renewable mix infra structure

8/8/2019 Renewable Mix Infra Structure

http://slidepdf.com/reader/full/renewable-mix-infra-structure 1/62

The Last Word: Will India Be the Next

Big Green Growth Market?By Klaus Peter Müller and Pratik Kadakia | October 4, 2010 | 0 Comments

By 2020 India aims to generate 15% of its electricity from renewable sources, excluding large

hydroelectric power plants, a goal that could pave the way for overseas investment.

India In 2009 India's installed renewable energy capacity, excluding large hydroelectric power plants,

was about 16 GW. In terms of installed wind capacity it ranked fifth in the world with more than 11

GW.

But despite this impressive set of figures, total power produced by this capacity currently accounts

for less than 2% of the total power produced in India. Assuming continued strong growth in electricity

consumption, India would need an installed renewable energy capacity of some 100²110 GW to

reach its 2020 target, meaning a capacity ramp up of about 8 GW/year.

As challenging as this may seem, other countries have already successfully demonstrated how to

quickly increase renewable energy growth rates in a relatively short period of time. For example,

since Germany's renewable energy law was passed in 2000 its installed renewable energy capacity

has grown at a compound annual rate of 16% from 11.9 GW in 2000 to 39.9 GW in 2008. Over the

same period, the total power produced in Germany from renewable sources soared by over 150%.Before the law was enacted, the country had only managed to achieve single digit growth rates for

renewable installations between 1990 and 2000.

Meanwhile, China has for the past five years doubled its installed wind capacity year-on-year, adding

13 GW in 2009. Latest official Chinese statistics show that the nation's renewable energy capacity is

now increasing at a faster pace than that of its coal plants.

Investors might look back and remember how India has in the past failed to achieve declared

ambitious growth targets in its power sector. For instance it fell about 40% short of its 2007²2008

capacity addition programme target, while the implementation of several of its infrastructure projects

have been beset with troublesome issues such as land acquisition.

However, there are five good reasons to believe that India will achieve ambitious renewable energy

growth rates soon.

Vast Renewable Resources



and the company, which also includes a majority holding in German manufacturer REpower, is the

third largest supplier globally and in 2009 held 10% of the market.

Threats from Climate Change

India is the fourth largest carbon emitter in the world and if its reliance on conventional energycontinues, emissions will increase further. The country's carbon dioxide emissions are expected to

triple by 2030 if the current dominance of conventional resources in the energy mix continues. The

country's National Action Plan on Climate Change has categorically called for keeping the per capita

greenhouse gas emissions below that of developed countries at any given point in time. By 2020,

India aims to reduce its emission intensity to 25% of the 2005 levels. Power from green energy plays

an important role in the portfolio of options pursued under the National Action Plan on Climate

Change.

However, players in Indian green electricity generation still face a number of critical challenges

today, some of which traverse all renewable technologies. These include inconsistent and unreliableincentive schemes; limited grid infrastructure/connectivity; difficulty in passing on the additional cost

of renewable power to final consumers; outdated or unavailable resource maps; as well as the

currently limited size and scale of domestic component production.

Meanwhile, some issues are more technology-specific. Wind faces hurdles in grid infrastructure and

power evacuation, a shortage of human talent and R&D capability, as well as difficulties in

recovering payments from distribution utilities.

Solar's problems, meanwhile, come from the high initial capital expenditure required and the fact that

a significant number of the most suitable sites are in remote regions which can add complexity to the

output transportation issue which may require additional transmisison infrastructure. Elsewhere

biomass has feedstock availability issues and low feed-in tariffs, while small hyrdoelectric power

plants face complex bureaucratic hurdles.

These challenges mean that decisive steps need to be taken in order to overcome the growth

barriers first and foremost by adapting the legislative framework and the introduction of a set of

renewable energy laws with clear guidelines. In addition, the industry would benefit from focusing on

creating a market for renewable energy by introducing renewable purchase obligations and securing

preferential grid access for renewable energy output.

The industry could also draw support from the strengthening of country's grid infrastructure throughthe introduction of a strict grid code and clear roles and responsibilities for the evacuation

infrastructure along with ownership and maintenance.

Evolving the grid infrastructure into smart grids would facilitate net-metering, which in turn could

significantly increase distributed power generation from renewable sources, especially wind and



solar. And by introducing land reform, sites that are rich in renewable energy resources could be

reserved for power generation.

The issues raised could be overcome with government support and industry leadership in the near

future and therefore investors should be positioning themselves already today to benefit from this

growing market.

Klaus Peter Müller is Partner in the Global Energy & Chemicals Competence Center with Roland

Berger Strategy Consultants. Pratik Kadakia is Practice Head Energy & Chemicals with Tata

Strategic Management Group.

R enewables Continue R emarkableGrowthBy Janet Sawin, Eric Martinot, David Appleyard | September 27, 2010 | 14 Comments

Renewables had another banner year in 2009, with policy, investment and market

development activity across a spread of nations - as recorded in the REN21 Renewables 2010

Global Status Report.

London, UK By 2010, renewable energy had reached a clear tipping point in the context of global

energy supply, concludes the 'Renewables 2010 Global Status Report'. With renewables comprising

fully one quarter of global power capacity from all sources and delivering 18% of global electricity

supply in 2009, the latest release of the definitive assessment of the state of the global renewable

energy industry from the Renewable Energy Policy Network for the 21st Century (REN21) details thecurrent status and key trends of global markets, investment, industry and policies related to

renewable energy.

Investment in new renewable power capacity continued to increase during 2009, despite challenges

posed by the global financial crisis, lower oil prices, and slow progress with climate change policy.

For the second year in a row, more money was invested in new renewable power capacity than in

new fossil fuel capacity. The renewable generating capacity installed over the past two years

accounts for nearly 50% of total generating capacity added to the world's grids over this period.

Furthermore, the rapid adoption beyond the industrialised world means that today more than half of

the existing renewable power capacity is in developing countries.

These trends reflect strong growth and investment across all market sectors including power

generation, heating and cooling, and transport fuels. Grid-connected solar PV has grown by an

average of 60% every year for the past decade, increasing 100-fold since 2000. During the period

from year-end 2004 through 2009, consistently high growth year-after-year marked virtually every

other renewable technology as well. During those five years, annual growth rates averaged 27% for



wind power capacity, 19% for solar water heating, and 20% for ethanol production. Indeed, as other

economic sectors declined around the world, existing renewable capacity continued to grow during

2009 at rates close to, or exceeding, those in previous years. Market growth for some technologies -

including wind and concentrating solar power, and solar water heating - exceeded their five-year

averages in 2009. Annual production of ethanol and biodiesel increased 10% and 9%, respectively,

despite layoffs and ethanol plant closures in the United States and Brazil. Biomass and geothermal

for power and heat also grew strongly last year.

Much more active policy development during the past several years culminated in a significant policy

milestone in early 2010 with more than 100 countries having some type of policy target and/or

promotion policy related to renewable energy in place. Most countries have adopted more than one

policy and there is a significant diversity of policy mechanisms in use at national, state/provincial and

local levels to advance renewable energy. In addition, many of the new targets enacted in the past

three years call for shares of energy or electricity from renewables in the 15%-25% range by 2020.

Renewable Energy Extends Its Reach

Recent trends also reflect the increasing significance of developing countries in advancing

renewable energy. Collectively, developing countries now account for almost half of the countries

with some sort of policy to promote renewable power generation, and they have more than half of

global renewable power capacity. Today China leads the world in several indicators of market

growth. India ranks fifth worldwide in total existing wind power capacity and is rapidly expanding

many forms of rural renewables such as biogas and solar PV, while Brazil produces virtually all of

the world's sugar-derived ethanol and has been adding new biomass and wind power plants.

Renewables markets are growing at rapid rates in several other developing countries such as

Argentina, Costa Rica, Egypt, Indonesia, Kenya, Tanzania, Thailand, Tunisia and Uruguay, to namea few.

The geography of renewable energy is changing in ways that suggest a new era of geographic

diversity. For example, wind power existed in just a handful of countries in the 1990s but now

operates in over 82 countries. Outside of Europe and the US, other developed countries like

Australia, Canada and Japan are seeing recent gains and broader technology diversification. The

developing world is experiencing a similar trend and, for example, today at least 20 countries in the

Middle East, North Africa and sub-Saharan Africa have active renewable energy markets. This

geographic diversity is boosting confidence that renewables are less vulnerable to market

dislocations in any specific country.

Meanwhile, leadership in manufacturing is shifting from Europe to Asia as countries like China, India

and South Korea continue to increase their commitments to renewable energy. In 2009, firms in

China produced 40% of the world's solar PV cell supply, 30% of the world's wind turbines (up from



10% in 2007), and 77% of the world's solar hot water collectors.

Figure 1. Installed capacity by region and technology for 2009

Renewables Investment Remains Robust

Greatly increased investment from both public-sector and development banks is also driving

renewables development. Excluding large hydro, total investment in renewable energy capacity was

about US$150 billion in 2009, up from the revised $130 billion recorded in 2008. Investment in new

renewable power capacity in both 2008 and 2009 represented over half of total global investment in

new power generation. However, investment in utility-scale renewable energy additions dropped 6%

in 2009 from the 2008 level, despite 'green stimulus' efforts by many of the world's major economiesand increased investments from development banks in Europe, Asia and South America.

All told, again excluding large hydro, the world invested $101 billion in new utility-scale renewable

energy development in 2009, compared with $108 billion in 2008. In 2009 there was also investment

of some $50 billion worldwide in small-scale projects such as rooftop solar PV and solar hot water.

An additional $40-$45 billion was invested in large hydropower.

Renewable energy companies invested billions of dollars in plant and equipment to manufacture

solar modules, wind turbines and other generating devices during 2009. Venture capital and private

equity investment in clean energy companies totalled $4.5 billion, down from $9.5 billion in 2008,

while public market investment in quoted clean energy firms reached $12.8 billion, up from $11.8

billion. Government and corporate research, development, and deployment spending on clean

energy technology in 2009 is estimated at $24.6 billion, up around 2% from 2008, the bulk (68%) of

which went to energy-efficiency technologies.



Germany and China were the investment leaders in 2009, each spending roughly $25-$30 billion on

new renewables capacity, including small hydro. They were followed by the US, investing over $15

billion, and Italy and Spain with about $4-$5 billion each.

The wind energy sector continued to be the hands-down leader, receiving 62% of the global total

invested - $62.7 billion in 2009, up from $55.5 billion the year before. Most of the growth was due toChina's rapid capacity expansion, increased investment activity in the wind sector in Latin America,

and a handful of large utility-backed offshore wind deals in the UK.

These gains were offset by a $5.6 billion drop in solar power asset investment, to $17.1 billion in

2009, and a plunge in biofuels spending, down to $5.6 billion from $15.4 billion in 2008. Lower

investment in PV in 2009 was due to several factors. One was the behaviour of prices along the

value chain, with PV module prices falling by some 50% over the year, bringing the dollar value of

financial investment down with them. Other factors included the Spanish government's cap on PV

project development at the end of the boom associated with the pre-September 2008 tariff, and the

shortage of debt finance for utility-scale projects in Europe and the US, which also affected windfarms. Concerns about scheduled reductions in feed-in tariff support for PV in some countries

actually spurred on developers rather than holding them back. Indeed, Germany witnessed a

spectacular end-of-2009 spurt in small-scale PV project construction.

In 2007, biofuels commanded 22% of global asset finance, with investment totalling $19.6 billion.

However, the sector slipped to $15.4 billion in spending in 2008 and just $5.6 billion in 2009,

representing only 5% of global project investment. An oversupply in US ethanol continued to

smother investment in the biofuels sector in 2009. Things may soon turn around as both Brazil and

the United States continue to follow ambitious biofuels targets. Brazil's state-owned oil company

Petrobras has moved into the ethanol sector, and US plants bought under bankruptcy auctions in2008 and 2009 have begun slowly to resume operation.

The decline in asset investment in biofuels relegated the sector to fourth place among the renewable

energy sectors in 2009. Stepping up to third place, after wind and solar, was biomass (including

waste-to-energy), with a rise in investment to $10.4 billion, from $9 billion in 2008.

In Europe, Brazil and elsewhere, the brightest feature for project investors during 2009 was the

expanded role of public sector banks. The European Investment Bank (EIB) and Germany's KfW

Banking Group, in particular, significantly raised their lending to renewable energy. The European

Bank for Reconstruction and Development (EBRD) played an active role in project finance, albeit not

on the scale of the EIB and KfW, as did the Brazilian National Bank of Economic and Social

Development (BNDES) for Brazilian projects (though its lending declined relative to 2008 levels).

This strong contribution by the public sector was all the more needed, because many commercial

banks - from Europe to the United States and elsewhere - found it impossible to sustain the 2008

level of lending to renewable energy projects. Overall, development assistance for renewables in

developing countries surged in 2009, up to $5 billion from $2 billion in 2008. For example, the World



Bank Group, including the International Finance Corporation and the Multilateral Investment

Guarantee Agency (MIGA), saw the largest increase to date in finance from previous years. Finance

rose fivefold in 2009 as $1.38 billion were committed to new renewables (solar, wind, geothermal,

biomass and hydro below 10 MW) and another $177 million to large hydropower.

Expanding the Reach of Policies and Targets

Growth in renewables is inevitably supported through government policy. Renewable energy policies

existed in a few countries in the 1980s and early 1990s, but policy support began to emerge in many

more countries, states, provinces, and cities during the period 1998-2005, and even more so during

2005-2010.

Many countries have adopted national targets for shares of electricity production. Targets are

typically for 5%-30% of electricity from renewable sources, but they range from 2%-90%. Many

historical targets have aimed for the 2010-2012 timeframe, but targets aiming for 2020 and beyond

have multiplied in recent years.

Developing nations now make up more than half of the countries worldwide with renewable energy

targets. The 'Renewables 2007 Global Status Report' counted 22 developing countries with targets,

a figure that had expanded to 45 by early 2010. Developing countries' targets are also becoming

increasingly ambitious. For example, China aims for 15% of final energy consumption from

renewables by 2020, even as total energy demand continues to grow at nearly double-digit annual

rates.

Several countries have adopted targets at state/provincial and regional levels - and at other levels as

well - with many mandated through renewable portfolio standards (RPS) and other policies.

In 2008, all 27 EU countries confirmed national targets for 2020, following a 2007 EU-wide target of

20% of final energy by 2020. It appears that many countries won't meet their 2010 targets by the end

of the year, although this won't be known immediately due to data lags. Nonetheless, some EU

countries were close to or had already achieved various types of national 2010 targets early in the

year, including France, Germany, Latvia, Spain and Sweden.

City and local governments around the world are also enacting renewable energy promotion policies.

Hundreds of cities and local governments have established future targets for renewables; urban

planning that incorporates renewables into city development; building codes that mandate or

promote renewables; tax credits and exemptions; purchases of renewable power or fuels for publicbuildings and transit; innovative electric utility policies; subsidies, grants, or loans; and many



information and promotion activities.

Figure 2. Growth in renewables capacity, annual and five-year average

Supporting Renewable Electricity Generation

At least 83 countries - 41 developed/transition countries and 42 developing countries - have some

type of policy to promote renewable power generation. The 10 most common policy types are feed-

in tariffs (FiTs), renewable portfolio standards, capital subsidies or grants, investment tax credits,

sales tax or VAT exemptions, green certificate trading, direct energy production payments or tax

credits, net metering, direct public investment or financing, and public competitive bidding.

The most common policy currently in use is the feed-in tariff, which has been enacted in many new

countries and regions in recent years. By early 2010, at least 50 countries and 25 states/provinces

had adopted FiTs over the years, more than half of which have been enacted since 2005.

Strong momentum for feed-in tariffs (FiTs) continues around the world as countries enact new

policies or revise existing ones. For example, France adopted a tariff for building-integrated PV that

was among the highest in the world (¼0.42-¼0.58/kWh). Other countries that adopted or updated

FiTs included the Czech Republic, Germany, Greece, India, Ireland, Japan, Kenya, Slovenia, South

Africa, Taiwan, Thailand, Ukraine and the UK. In some countries, tariffs were reduced in response totechnology cost reductions, market slowdowns and concerns about foreign manufacturer market

share; indeed, reductions were more prevalent in 2009 and early 2010 than in previous years.

Renewable portfolio standards (RPS) - also called renewable obligations or quota policies - exist at

the state/province level in the US, Canada and India, and at the national level in 10 countries:

Australia, Chile, China, Italy, Japan, the Philippines, Poland, Romania, Sweden and the UK.



Globally, 56 states provinces, or countries had RPS policies in place by early 2010. Most RPS

policies require renewable power shares in the range of 5%-20%, typically by 2010 or 2012,

although more recent policies are extending targets to 2015, 2020 and 2025. Most RPS targets

translate into large expected future investments in renewable generation, although the specific

means (and effectiveness) of achieving quotas can vary greatly across countries or states.

Investment tax credits, import duty reductions and/or other tax incentives are also common means

for providing financial support at the national level in many countries, and at the state level in the

United States, Canada and Australia. Many tax credits apply to a broad range of renewable energy

technologies, such as Indonesia's new 5% tax credit adopted in early 2010, and a new 2009 policy in

the Philippines for seven-year income tax exemptions and zero-VAT rates for renewable energy

projects.

Energy production payments or credits, sometimes called 'premiums', also exist in a handful of

countries while capital subsidies and tax credits have been particularly instrumental in supporting

solar PV markets. Net metering (also called net billing) is an important policy for rooftop solar PVand laws now exist in at least 10 countries - including a growing number of developing countries. A

few jurisdictions are also begining to mandate solar PV in selected types of new construction

through building codes.

Supporting Renewable Heating & Transport

More countries are also adopting policies to support renewable heat and transport. The primary

focus of heat-related measures has been solar water heating, and mandates for solar hot water in

new construction represent a strong trend at both national and local levels. For years Israel was the

only country with a national level mandate, but Spain followed in 2006 with a national building code

that requires minimum levels of solar hot water in new construction and renovation. Solar thermal

systems must meet 30%-70% of energy needs for hot water, depending on climatic zone,

consumption level, and backup fuel. Many other countries have since followed suit. South Korea's

new 2010 mandate requires on-site renewable energy to contribute at least 5% of total energy

consumption for new public buildings over 1000 m2, for example. Other countries with solar hot

water targets include Morocco and Tunisia.

Capital subsidies for solar hot water are now a common policy in many states and countries. At least

20 countries, and probably several more, provide capital grants, rebates, VAT exemptions, or

investment tax credits for solar hot water/heating investments, including Australia, Chile, Japan, New

Zealand, Portugal, Spain, and Uruguay.

In the transport sector, mandates for blending biofuels into vehicle fuels have been enacted in at

least 41 states/provinces and 24 countries at the national level. Most mandates require blending

10%-15% ethanol with gasoline or 2%-5% biodiesel with diesel fuel. Mandates can now be found in

at least 13 Indian states/territories, nine Chinese provinces, nine US states, five Canadian provinces,

two Australian states, and at least 14 developing countries at the national level.



In addition to mandated blending, several targets and plans define future biofuel use. Countries with

production or use targets include the US, the UK, Japan, China and South Africa. Targets for

renewable energy's share of transportation energy exist in at least four EU countries at the national

level (Belgium, Croatia, France and Portugal), as well as the EU-wide target of 10% of transport

energy by 2020, covering both sustainable biofuels and electric vehicles.

Basis for Optimism

Almost all renewable energy industries experienced manufacturing growth in 2009. It must be

conceded, however, that many capital expansion plans were scaled back or postponed.

The REN21 Renewables 2010 Global Status Report reveals that for the second year in a row, in

both the United States and Europe, more renewable power capacity was added than conventional

power capacity from fossil fuels or nuclear. China added a staggering 37 GW of renewable power

generation capacity in 2009, more than any other country in the world, to reach 226 GW installed.

Globally, nearly 80 GW of renewable power capacity was added, including 31 GW of hydro and 48GW of non-hydro capacity.

Indeed, wind power additions reached a record high of 38 GW - China was the top market, with 13.8

GW added. Solar PV additions reached a record high of 7 GW - Germany was the top market, with

3.8 GW added. And many countries saw record biomass use - notable was Sweden, where biomass

accounted for a larger share of energy supply than oil for the first time. And biofuels production

contributed the energy equivalent of 5% of world gasoline in 2009.

Even the most cynical observer must acknowledge this is a success story by any means, let alone

under the current economic climate. Renewable energy is now breaking into the mainstream of

energy markets thanks to hundreds of new government policies, accelerating private and public

investment, and numerous technology advances achieved since the first Renewables Global Status

report was released in 2005.

Despite the continuing advances highlighted in this year's report, the world has tapped only a

fraction of the vast renewable energy resources available to us. Further strengthening of policy

support can help drive the massive scale up in renewables needed for the sector to play a major role

in building a stable, secure and enduring low-carbon global economy.

David Appleyard is chief editor of Renewable Energy World. Janet Sawin is research director (2008-

2010) and lead author of the REN21 Renewables Global Status Report. She is also a partner at

Sunna Research and a senior fellow with the Worldwatch Institute. Eric Martinot is research director

emeritus and lead author of the REN21 Renewables Global Status Report. He is also a senior

research director at the Institute for Sustainable Energy Policies and a senior fellow with the

Worldwatch Institute.



Most of the investment data was provided by Bloomberg New Energy Finance (BNEF). See also the

UNEP/BNEF report Global Trends in Sustainability Energy Investment 2010 , which was released

jointly with the REN21 report.

Sidebar: Renewables Investment Trends in 2010

The first quarter of 2010 found the renewable energy sector largely out of the limelight, following the

inconclusive Copenhagen climate change conference in December 2009. However, investment

continued at a level significantly above that of a year earlier. Investment in clean energy assets (not

including large hydro) was $29.5 billion in the first quarter of the year, some 63% above that in the

same period of 2009. It was up from $26 billion in the fourth quarter of 2009, a strong result given

the continuing uncertainties in the world economy and the financial markets and the impact of the

Northern Hemisphere winter on project progress. The highlights of the first quarter included a

healthier figure for asset finance in the United States, at $3.5 billion from $2.3 billion in the fourthquarter of 2009, helped by a $394 million construction debt package for a California wind farm and

another big number for China, $6.5 billion, reflecting its investment in wind 'mega bases' and smaller

projects. The quarter was also notable for a continuation of the recovery in venture capital and

private equity investment in clean energy. This reached $2.9 billion, up from $1.7 billion in the fourth

quarter of 2009 and $1.5 billion in the first quarter of 2009.

Mix'n'Match Hybrids BoostR

enewable Load FactorsBy Elisa Wood | October 4, 2010 | 4 Comments

Hybrid energy systems are emerging in both utility-scale plants and on-site generation

applications, wedding green technology with fossil fuels or other renewables to enhance

supply and cut emissions.

Barboursville, Virginia, USA Policymakers often portray energy sources as nearly at war with one

another in an epic struggle of green versus brown, with the winner ultimately powering the world. But

in today's real world of grid operation, renewable and fossil fuel resources are treated more as allies,

as pieces of a puzzle, which when fit together properly, keep on the lights with minimum impact onprices and the environment.

Sometimes this means placing power plants strategically on an electric grid. Fossil fuel plants and

wind farms, for example, might be sited near one another to ensure reliability. Or, increasingly, grid

planners look to the cutting edge approach of building hybrid power plants, one facility that combines

two technologies, such as coal and solar, gas and solar, wind and solar, or more conventional



biofuel and coal. Such pairings allow the virtues of one fuel type to compensate for the failings of

another.

"We're in a fairly early stage in the evolution of the hybrid combination projects. There are still

problems to work out, but there is motivation to do this," said Roger Rosendahl, a partner at DLA

Piper , which specialises in global project finance.

Indeed, the march toward hybridisation has led the Electric Power Research Institute to launch two

demonstration studies in the US on solar energy and fossil fuel combinations, aimed at providing

information for utilities that want to build similar projects. The demonstrations are underway in New

Mexico at the 245 MW Escalante coal-fired plant and in Nevada at the 1102 MW Chuck Lenzie gas-

fired plant. These hybrid systems inject steam heated by solar energy into the steam cycle of the

fossil plants. The fossil fuels provide steam when the sun isn't shining. When it is shining, the solar

power offers a lower-cost, low-emissions energy source.

The idea of using two fuels in the same plant is not new; for decades the power industry has useddual-fuel gas- and oil-fired plants. When natural gas is in short supply, plant operators switch to oil.

Similarly, the pulp and paper industry has for years operated on-site generators that can use coal or

woody byproducts as fuel.

"It is less of a technology play and more of a maturation of the industry. People are figuring out how

to do these things using more or less conventional technologies," says Maurice Gunderson, senior

partner at CMEA Capital. "The reason for doing the flexible-fuel power plants is different from the

reason for doing the gas-supplemented solar. The gas-supplemented solar is for firming up the

supply when the cloud comes over. And the flexible fuel is primarily driven by the need to generate

power given the fuel you have available that day."

So the newer hybrid plants tend to hold answers to larger grid problems, particularly how to maintain

reliability while introducing renewable energy into a system that Gunderson says in the US is more

like a "pile of spaghetti" than carefully drawn lines. "The hybrid energy projects of today are really

addressing a very particular problem: intermittency," adds David Huard, chairman of Manatt,

Phelps & Phillips' Energy, Environment and Natural Resources practice. "Most renewable forms of

energy, not all, have a period of time in which they have less reliability or production of power,

especially if they are in a remote location," he says.

Connecting an intermittent source of power into transmission line is "very inefficient and expensive",

he says, which lends weight to the idea of using a hybrid approach in grid planning. But hybrid

systems have their own problems, particularly in defining how much of a hybrid's power can be used

to meet state renewable portfolio standards in the US. "What do you call this? Is this renewable? If

it's renewable for 16 hours a day but the dirtiest stuff on earth for 8 hours, do you average?" says

Huard.



While problems of definition have yet to be resolved, hybrid systems are cropping up worldwide

using various technologies.

Italy's New Molten Salt Hybrid

In Italy, Enel made history in July by unveiling the Archimede power plant in Sicily, which thecompany said is the first combined-cycle gas/solar thermal electric plant to use molten salts for heat

transfer.

Like several other concentrating solar power plants, Archimede uses heated molten salts to store

energy, so that at night or in overcast conditions it can still produce electricity. What's unique about

the project is that the molten salts are not only used to store energy, but also to capture the sun's

heat. Archimede contains 30,000 m of parabolic mirrors that heat the transfer fluid pipes. By using

the molten salts to capture heat, the plant can operate at higher temperatures (up to 550°C) than if it

used oil for energy capture. Enel estimates that the 5 MW solar portion of the plant saves about

2100 tonnes of oil equivalent annually.

In Colorado, Xcel Energy is now testing a demonstration hybrid solar-coal plant. The Colorado

Integrated Solar Project adds parabolic-trough technology, developed by Abengoa Solar , to Unit 2 of

the coal-fired Cameo Generating Station. Eight rows of solar troughs decrease the 49 MW plant's

use of coal and lower its carbon dioxide emissions. The $4.5 million pilot project will attempt to

discern if the approach is commercially viable and efficient.

"If this project produces the successful results we expect, this type of solar thermal integration will

help move the use of solar energy one step closer to being a potential technology for improving the

environmental performance of coal-fired power plants for Xcel Energy and for utilities around the

country," said Kent Larson, Xcel vice president and chief energy supply officer.

While the Archimede plant is cutting edge, other hybrid technologies have been around for years,

such as coal-fired/biofuel hybrid plants, which offer one of the simplest ways to utilise biomass. No

specialised technology is necessary, nor is much modification made to existing coal plants. Biomass

is simply burned in the furnace of a conventional coal plant.

Such plants are more prevalent in Europe than in the US. Europe has roughly 100 coal

firing/biomass units, many operating commercially, according to the European Biomass Industry

Association. The International Energy Agency reports that the US has about 40 coal-firing/biomass

plants and Australia has 10.

Biomass/coal combinations, however, sometimes come under criticism from environmental groups.

They admit that hybrids emit less carbon dioxide than plants solely fuelled by coal, but argue that

biofuels could extend the life of less-efficient coal plants that would otherwise be retired because of

high emissions.



Moreover, biomass from wood is under increased scrutiny in the US. The state of Massachusetts

may prohibit utilities from using wood-fuelled plants to meet its renewable portfolio standard, except

in combined heat and power plants. The state's Department of Energy Resources is contemplating

the rule change based on a report from the Manomet Centre for Conservation Sciences that says

biomass may not be carbon neutral, depending on how trees are harvested, and could increase

greenhouse gases more than coal-fired generation over the long term.

Pairing Green With Green

Meanwhile, new and more innovative combinations of fuel and technology are being matched into

hybrid operations.

California company Skyline Solar has developed an all-solar hybrid that the company says uses the

best aspects of tracked photovoltaics and concentrating solar power to lower energy costs through

higher energy yield per peak watt installed. "The product we are commercialising is a hybrid with a

rack PV system using conventional flat plate silicon and parabolic trough solar thermal," says BobMacDonald, Skyline Solar's co-founder and chief technology officer. "We are using a lot of the

attractive attributes of CSP, but we are using silicon based flat panels that focus sunlight."

Skyline calls its technology High Gain Solar (HGS). Manufactured with the same materials as

traditional solar panels, but smaller in size, the systems include a backing plate, silicon cells,

encapsulant, and junction box. What's different is that the HGS system includes a metal heat sink

that allows passive convection cooling.

The application works best in projects up to 20 MW, which makes HGS projects ideal for

municipalities and manufacturers, says MacDonald. In addition, because the components are PV

rather than CSP, they are "human scale" versus the "Jurassic scale" of a typical CSP plant, he says.

As a result, Skyline project components are easier to manufacture and transport than CSP, the

company claims.

In Turkey, Solimpeks Solar Energy has also merged solar electric and thermal energy capture into

one technology, called the Volther hybrid solar collector, designed for buildings. Water circulates

near the PV panels to absorb their heat. The hot water can then be used in the building. By

producing both electricity and heat from the same panel, such hybrid systems offer a quicker return

on investment, according to Solimpeks. The water absorption also acts to cool the PV panel,

increasing its conversion efficiency and longevity.



A hybrid solar PV/solar thermal installation in Instanbul (Credit: Solimpeks)

California company PVT Solar offers a variation on this theme with its Echo solar system, which

combines PV and thermal solar for homes. Rather than capturing the heat by running water througha copper tube, which could damage the roof if it leaks, Echo uses a computerized fan to draw hot air

from under the solar panel at a rate of about 14 m³/m. The air is used to heat the home or its hot

water.

Gordon Handelsman, PVT Solar president, says Echo is highly efficient because it uses the same

panel to produce both electricity and heat. While a solar panel typically converts 15% of sunlight to

energy, with the rest lost as heat, the Echo system hit 50%, he says.

A typical 2 kW system produces more heat than a home can use, he says. "We don't run out of

electricity; we run out of load." The company has field-tested the systems, beginning in 2004 with aUS Department of Energy grant. By the first quarter of this year it had 50 systems on rooftops, and

has been adding them at a rate of about 50 per month. Meritage Homes, a major American home

builder, is incorporating the system in relatively modestly priced homes ² under $180,000 ² in the

Phoenix, Arizona area. The Echo system also can be found in Utah and soon California, says

Handelsman.

Meanwhile, Urban Green Energy has developed a wind/solar hybrid to light up streetlamps. The

Sanya Wind Solar Hybrid Streetlamp combines a 600 W vertical-axis wind turbine with 80 W solar

panels, and a battery bank that can store up to five days worth of energy. The lamps can also be

hooked up to a grid, feeding off any excess energy produced and providing emergency backup in

case of prolonged periods of low wind, although the company expects the units to generate energy

365 days a year.

Urban Green Energy, which had orders to ship the units to South Korea, Poland, the US, and the US

Virgin Islands, says the lamps are customised to specific locations with the goal of making the

streetlamps as maintenance-free as possible. Those using the units include a US Air Force base in



Kansas, a girls' school in the Great Rift Valley in Kenya, and the Raising Malawi Academy for

Girls, an orphan care initiative sponsored by performer Madonna.

Common Ground for Cows and Computers

An even more futuristic possibility for hybrid energy pairs energy-hungry data centres and grass-hungry cows. Hewlett-Packard researchers presented a paper in May at the ASME International

Conference on Energy Sustainability in Phoenix, Arizona that found a medium-size dairy farm, one

with about 10,000 dairy cows (that's about 200,000 tonnes of manure per year) could fulfil the

energy needs of a 1 MW data centre. The system would even have enough power left over to

support the needs of the farm.

The researchers propose a combined heat and power system that would provide power to the data

centre, which would in turn feed its waste heat back into the CHP system. The heat from the data

centre would speed up the anaerobic digestion of the manure to create methane gas for generating

electricity for the data centre.

HP's model addresses the problem that farmers have in disposing of cow manure. It may even make

the farmers some money: Researchers suggest farmers would break even within two years, and

make roughly $2 million a year selling waste-derived power to data centres. The idea of co-locating

data centres and farms makes sense, given that Google, Yahoo, Microsoft and others have begun to

build on inexpensive rural land, the study said.

"The idea of using animal waste to generate energy has been around for centuries, with manure

being used every day in remote villages to generate heat for cooking. The new idea that we are

presenting in this research is to create a symbiotic relationship between farms and the IT ecosystem

that can benefit the farm, the data centre and the environment," said Tom Christian, principal

research scientist of HP's Sustainable IT Ecosystem Lab.

Hybrids as Transitional

One of the most talked about US hybrid projects is being built by renewable energy leader, Florida

Power & Light. Called the Martin Next Generation Solar Energy Centre, the plant will use 75 MW

parabolic troughs to supplement its natural gas. The project broke ground in 2008 and is scheduled

to be finished in 2010.

The fossil/green hybrid may not be an end in itself, but could prove to be transitional, a vital stepaway from fossil fuel dependency to a renewable energy future, says QGEN, a Boston-based

development company. CEO Wael Almazeedi, who also founded international energy development

company BTU Power, plans to sell hybrid designs as intellectual property. Still somewhat in stealth

mode, QGEN was close to finalising a hybrid industry consortium as REW went to press. The

consortium's objective is to lead the way in hybrid design and development.



On its website, QGEN says we stand at "a watershed moment" in energy history. Transition to clean

energy "will require more than disruptive new energy technologies; the energy industry is not known

for embracing radical change. It will also require game-changing evolutionary technologies such as

hybrid generation in which state-of-the-art renewable energy technologies are integrated into

conventional fossil fuel plant designs. Hybrid generation will ensure that renewable energy

technologies are commercially competitive by deploying them as a complement to existing fossil fuel

plants, rather than an outright substitute."

At some point renewable energy may be the outright substitution for fossil fuels. But for now it

appears plenty of room exists for fossil fuels and green supply to work in a kind of détente that

brings new efficiency to the power grid.

plants, the economics of the integrated solar steam cycle applications were favorable.

"

Solar PV technology owes its existence as we know it to Edmund Bequerel, Albert Einstein, and

other historical figures. Today, this spirit of technological advancement and ingenuity is alive and

well.

The photoelectric effect was first noted by a French physicist, Edmund Bequerel, in 1839, who found

that certain materials would produce small amounts of electric current when exposed to light. In

1905, Albert Einstein described the nature of light and the photoelectric effect on which photovoltaic

technology is based, for which he later won a Nobel prize in physics. The first photovoltaic module

was built by Bell Laboratories in 1954. It was billed as a solar battery and was mostly just a curiosity

as it was too expensive to gain widespread use. In the 1960s, the space industry began to make thefirst serious use of the technology to provide power aboard spacecraft. Through the space programs,

the technology advanced, its reliability was established, and the cost began to decline. During the

energy crisis in the 1970s, photovoltaic technology gained recognition as a source of power for non-

space applications.



In this section, we salute a few of the technologists that have made this incredible journey possible,

and those who have more recently joined the incredible worldwide effort that is making PV a viable

competitor to existing power generating technologies.

To get a better understanding of what today¶s top technologists see as the key drivers and

challenges in PV today, we asked them to answer take a few questions about the major trends in thephotovoltaics/solar power industry today, and key challenges facing the industry not only in terms of

technology, but in economics and politics as well.

Charlie Gay, Applied Materials

Charlie Gay was named president of Applied Solar and chairman of the Applied Solar Council at

Applied Materials, Inc. in 2009. Gay is also a co-founder of the Greenstar Foundation, an

organization that delivers solar power and internet access for health, education and microenterprise

projects to small villages in the developing world. Greenstar has been recognized for its innovation

by the World Bank, the Stockholm Challenge, the Technology Empowerment Network and the TechMuseum Awards.

Gay began his career in 1975 designing solar power system components for communications

satellites at Spectrolab, Inc. and later joined ARCO Solar, where he established the research and

development program and led the commercialization of single crystal silicon and thin film

technologies. In 1990, Gay became president and chief operating officer of Siemens Solar Industries

and from 1994 to 1997, he served as director of the U.S. Department of Energy¶s National

Renewable Energy Laboratory, the world¶s leading laboratory for energy efficiency and renewable

energy research and technology. In 1997, Gay served as president and chief executive officer of

ASE Americas, Inc., and in 2001 became chairman of the advisory board at SunPower Corporation.

Gay has a doctorate degree in physical chemistry from the University of California, Riverside. He

holds numerous patents for solar cell and module construction and is the recipient of the Gold Medal

for Achievement from the World Renewable Energy Congress.

We asked Gay to answer take a few questions about what he saw as the major trends in the

photovoltaics/solar power industry today, and key challenges facing the industry in terms of

technology as well as economics and politics. Here¶s what he said:

³As you know, I¶ve been in this industry for 35 years, and I¶ve seen a lot of promising starts that

didn¶t amount to much. This time is different: we¶ve entered the zone of inflection and LCOE iscompetitive to gas-firing plants at 15 cents kWh, with more than 50% drop in just the last three

years. It¶s very, very gratifying to watch this transpire.

³Moving forward, the industry will continue to drive down cost-per-watt, largely through increasing

the conversion efficiency and reducing manufacturing costs. As we advance efficiencies, we need to



tighten integration of equipment, materials and process. To do this will require greater sophistication

and automation for line balancing yield management, materials handling and integrated MES.

³Meanwhile, a lot has been written about China as a producer of PV wafers, cells and modules. It¶s a

trend we are watching unfold this year, with over 80% of new orders originating in Asia, dominated

by China. They are also becoming a leading consumer of solar PV energy as the Chinesegovernment has been active in putting a policy framework in place to emerge as a #1 consumption

market.´ Gay said.

As far as major technical challenges facing the photovoltaics industry moving forward, Gay said

these are primarily associated with the need for higher efficiencies and increased manufacturing

productivity.

³Regarding conversion efficiencies, most roadmaps are being implemented on a continuum of

technical improvements. Today, using screen printing technology, innovative double printing

techniques are making contact lines ever finer, minimizing the amount of light blocked from gettinginto the solar cell. We¶ve also entered the stage of expanding the use of selective emitters, some of

which are facilitated by screen printing and by new materials for forming the junction.

³We¶re also seeing the back of the cell receive more attention for various kinds of back contact

configurations where more reflective metallization is possible through simplified back etching of cells,

and the high reflectance properties of using aluminum.

³As we strive to improve efficiency, another area being looked at is minimizing surface

recombination. Surface recombination of course happens on the front and the back of the solar cell,

and we¶re developing unique solutions that allow optimal processing for both front and to back

properties where the different conductivity types require different film properties.

³Beyond process, there is also a movement toward improving factory automation for better

metrology and inspection -- and the capability to make and handle thinner wafers, which helps bring

down the direct cost of materials in the use of silicon.

³This next generation of PV solar is really a solutions game that far more complex than just tool

making. And it¶s precisely why I joined Applied Materials. Applied has the unique perspective and

experience to deliver precisely these kind of manufacturing solutions to market, having successfully

done the same for both the semiconductor and display industries.

³Now it¶s solar¶s turn to move from boutique to mainstream. I remember when it took the industry a

week to manufacture a single megawatt. Today the industry can crank out a megawatt in 30

minutes,´ he said.

What are the major economic/policy/regulation challenges facing the photovoltaics industry moving

forward? Gay said a number of specially crafted policies and incentives are needed to create a more



robust foundation for growth. ³For example, strong government support for renewables in Germany

and China has turned these countries into global leaders in this market. However, despite the

economic and global policy challenges and uneven progress worldwide in 2009, the market for solar

PV grew 60% year-over-year and the outlook for 2010 remains positive. We¶re expecting a range of

30-50GW of new manufacturing capacity to be added over the next three years. So we believe that

the solar market is still very dynamic and poised to grow,´ Gay said.

Daniel M. Kammen, U of California, Berkeley

Daniel M. Kammen is the Distinguished Professor of Energy at the University of California, Berkeley,

where he holds appointments in the Energy and Resources Group, the Goldman School of Public

Policy, and the department of Nuclear Engineering. Kammen is the founding director of the

Renewable and Appropriate Energy Laboratory (RAEL) and the co-Director of the Berkeley Institute

of the Environment. In April 2010 Kammen was named by Secretary of State Hilary R. Clinton to be

the first Clean Energy Envoy to the Americas.

Kammen received his undergraduate (Cornell A., B. ¶84) and graduate (Harvard M. A. ¶86, Ph.D. ¶88)

training is in physics. After postdoctoral work at Caltech and Harvard, Kammen was professor and

Chair of the Science, Technology and Environmental Policy at Princeton University in the Woodrow

Wilson School of Public and International Affairs from 1993 to 1998.

He then moved to the University of California, Berkeley. Kammen directs research programs on

energy supply, transmission, the smart grid and low-carbon energy systems, on the life-cycle

impacts of transportation options including electrified vehicles and land-use planning, and on energy

for community development in Africa, Asia, and in Latin America. Daniel Kammen is a coordinating

lead author for the Intergovernmental Panel on Climate Change (IPCC), which won the Nobel Peace

Prize in 2007. Kammen is the co-developer of the Property Assessed Clean Energy (PACE)

Financing Model: energy efficiency and solar energy financing plan that permit installation of clean

energy systems on residences with no up-front costs. PACE was named by Scientific American as

the #1 World Changing Idea of 2009 (co developer with Cisco¶s DeVries). Kammen serves on the

National Technical Advisory Board of the U. S. Environmental Protection Agency. He hosted the

Discovery Channel series µEcopolis, and had appeared on Frontline, NOVA, and twice on ¶60

Minutes¶. Kammen is the author of over 220 journal publications, 4 books, 30 technical reports, and

has testified in front of state and the US House and Senate over 30 times.

Kamen said he¶s very excited two trends in the photovoltaics/solar power industry today. ³One is the

steady push for $/watt parity with fossil fuels, through cost/watt innovations, building integrated cells,

and markets that reward peak demand coincidence. The incredible wave of technical innovations in

conventional cells, thin-film, and nano-solar technologies make this a very hopeful path,´ he said.

³The second is a broader push to rationalize energy markets so that rates reflect both externalities

(e.g. the REGGI carbon market, and California's soon-to-be-launched one) and actual supply and

demand -- real-time pricing -- and both are vital innovations that reward clean energy, and in many

ways solar in particular.´



Kammen said the biggest technical challenge facing the industry is low $/watt, not necessarily

highest efficiency. ³Thin film solar, and nano-solar both show incredible potential, and what is really

needed are the sustained research support -- both from the public and private sectors -- to bring

these to market,´ he explained.

The major economic/policy/regulation challenges facing the photovoltaics industry moving forward?³Clearly we have to overcome the up-front cost barrier, which is why I've been working so hard on

PACE financing (see http://rael.berkeley.edu/financing ) as this make the up front funds available to

break the cost/lifetime logjam

that keeps solar out of everyday energy and construction markets,´ Kammen said. ³ALL new homes

come with a solar option, built into the overall cost.´

T erry Bailey, Soliant Energy

Dr. Terry Bailey is president, chairman and CEO of Soliant Energy. Prior to leading Soliant Energy,

Bailey spent five years with Evergreen Solar as Senior Vice President of Marketing and Sales. Whileat Evergreen Solar, he participated directly as part of the senior management supervisory team in

the conception, design and execution of several solar factories. Specifically these included a 100MW

solar wafer factory located in Wuhan, China; a 450,000 sq. ft., 160MW factory located in Devens,

MA, consisting of three distinct fab areas for solar wafer production, solar cell production and solar

module production; and two wafer, cell and module fabs of 30MWp and 60MWp respectively located

in Thalheim, Germany. These efforts grew Evergreen's (and German joint venture EverQ's) sales

from 3MW per year to 250MW in four years, and created a total backlog of over 1GW of take-or-pay

orders, representing $3 billion of value.

Bailey earned a Ph.D. in analytical chemistry from Florida State University, specializing in nuclear

magnetic resonance research and computer system graphics integrations. He holds a B.S. in

Chemistry from the University of Alabama.

Bailey said while there are many trends that could be detailed, two stand out in his mind: Maturation

and stratification. ³While certainly still an infant compared to the power industry as a whole, PV is

beginning to settle into the existing structures and no longer must run maverick all the time versus

the entrenched technologies and utilities. As a result of both governmental programs and pressures,



and hopefully enlightened self interest, the utilities are structuring ways to integrate and properly

utilize the intermittent renewable energy sources, including solar. Slowly, banks and other sources of

financing are coming to understand PV and therefore how to value it and provide capital

appropriately to those wishing to deploy PV. This is certainly simpler and more advanced in Europe,

but even in the US there are welcome trends in this direction. The companies in our industry which

are pioneering PPA structures and then evolving them to optimally fit the market requirements are

creating increased value, not only for themselves but for the industry in total. Our little ecosystem is

still fragile but is finding its fit within the larger macro environment to ensure long term sustainability,

rather than bursts of activity generated almost solely from governmental largesse.

³The solar power industry can be discussed at the gross macro level, but the interesting trend is the

appropriate stratification which is occurring as part of the natural evolutionary development,

Darwinian PV if you will. An overriding driver of the industry is and should be to reduce the cost per

kWh generated, but layered on top of this is stratification of the different solar power technologies

into market and application slices where they best fit. This stratification is not perfectly clean, not will

it be so in the near future, but the trend is certainly there based on the core performance differentialsfor different technologies as well as the ever present pressures of government. A few examples may

suffice to make the point.

³If there is a specific demand for a very high energy output, with local energy storage then a molten

salt heliostat based system may be the best solution, but you would certainly never put this in or

near a heavily populated area, nor of course in an area with low DNI. If you have unlimited land

space, and no restrictions on shading the ground beneath, perhaps a thin film based array would

best suit the requirements. However if there is a requirement to maintain agricultural capability

beneath a PV array, and there is sufficient DNI, then a high concentration PV solution would fit best.

If you have limited area, such as on a commercial rooftop, land fill etc and the desire is greatestenergy density, or max kWh/kW installed then a specialized rooftop high concentration PV solution

would fit best in a good DNI area.

³So while a general purpose, lowest cost least common denominator PV solution is certainly

dominant in many areas, evolution has taught us that in specialized habitats the winner is a

specialized solution. The point is that there is no one right answer, but a more right answer for each

application and different technologies stratifying in this way is a natural and beneficial path for solar

power in general as it takes its place more prominently in the overall power industry,´ Bailey said.

In terms of major technical challenges facing the photovoltaics industry, Bailey agrees that cost per

Watt rises above all else. ³While there are innumerable individual technical challenges for each

different form of PV, at the top level the overriding challenge will remain reducing the LCOE, or cost

per kWh delivered by solar, such that the initial capital costs of an installation are readily perceived

as nominal and acceptable to the market. In general of course this means continually reducing costs,

increasing performance, or preferably both. It is important to note that cost reduction should

absolutely not be looked at as solely at the PV panel level. In the end the cost which matters is the

total installed system cost. Therefore it is both permissible and desirable for changes at the panel



level which may add cost, but which allows for a net reduction in the total installed system cost. Of

course the various pieces of the value chain must appropriately share in the benefits or there is no

real reason for panel manufacturers to add cost to their product,´ Bailey said.

More specifically, Bailey sees the following challenges as critical:

y Thin film generally should have a COGS advantage but must continue to dramatically

increase solar conversion efficiency to take advantage at the total installed system cost and

LCOE levels and stay ahead of others. Depending on the specific thin film technology

discussed then there are also issues to be solved to perfect the form factor of the product,

flexible for some applications for instance, while maintaining extremely long working lifetimes

of the product.

y Crystalline silicon is approaching the practical limits of performance without some radical

breakthroughs. For this technology continued reduction of COGS is the primary challenge.

There are some efforts to effect this not just with decreased silicon costs and base

performance but semi-passive low concentration schemes.y High Concentrating PV must continue to exploit the significant solar efficiency advantage

offered by multi-junction cell technology. There is increasing participation by companies, both

start-up and extremely large, in pushing the limits of this cell technology well beyond the

current ~40% efficient cells being sampled. Many roadmaps from these companies show

paths to ~50% cells in the reasonable future. High concentration PV by definition means two

axis tracking is required, so continued technical development in trackers and form factor is

required in order to reduce COGS while maintaining pointing tolerance sufficient to service

continually increasing concentrations levels of 1,000X and more.

The major economic/policy/regulation challenges facing the photovoltaics industry moving forward?Bailey says it¶s rapid fluctuations. ³The industry would be much better served with a less lucrative,

steady set of policies and regulations, than those which foster excessive growth too quickly. We

have been, and still are, dependent to a large degree on government programs to drive the growth in

PV. Unfortunately, government regulation generally also means increased costs in many ways,

especially when those programs are not uniform. This is especially apparent in the US where the

complexity of policy and economic programs can be staggering and certainly sometimes an obstacle

for adoption of solar while at the same time providing one of the underlying economic drivers. It does

our new industry no good to complain that all other energy sources have always been more

subsidized in reality than solar, although this is quite true. Rather our path to success will continue to

be to push for reasonable enabling government support of this remarkable distributed and unlimited

energy generation until the economics of solar are overwhelmingly favorable to the market, Bailey

said.

Ajeet Rohatgi, Suniva, Georgia T ech

Dr. Ajeet Rohatgi is a Regents' Professor and a Georgia Power Distinguished Professor in the

School of Electrical Engineering at the Georgia Institute of Technology (Georgia Tech), where he



joined the ECE faculty in 1985. He is the founding director of the University Center of Excellence for

Photovoltaic Research and Education (UCEP) at Georgia Tech. Dr. Rohatgi is also the Founder and

CTO of Suniva, Inc. a manufacturer high-efficiency, low-cost monocrystalline PV cells, using unique

processes and techniques that evolved from his work at UCEP. Dr. Rohatgi continues his research

interests in the development of cost and efficiency roadmaps for attaining grid parity with silicon PV,

and innovations in cell design and technology.

Under Dr. Rohatgi's leadership, Suniva has accomplished several industry firsts and achievements

in manufacturing, technology, research, and development, including the fastest ramp-up to 100MW

production in the industry; the raising of $130 million in capital following the formation of Suniva in

2007; the successful production of cell efficiencies exceeding 18%; pilot production of cell

efficiencies exceeding 18.5%, and R&D cell efficiencies exceeding 20%. Today, Suniva is the

highest cell efficiency producer in the U.S.

Dr. Rohatgi is an IEEE Fellow. He has published more than 370 technical papers in the PV field and

has been awarded 11 patents. Dr. Rohatgi has been widely recognized for his research anddevelopment contributions:

y Recipient of the 2010 Outstanding Achievement in Research Innovation Award, nominated

on behalf of the faculty of the School of Electrical and Computer Engineering

y Leadership in Technology award by Renewable Energy World for his achievements in

advancing the market for renewable energy in North America, 2010

y Envention Award by Atlanta Business Chronicle for conservation and pollution-curbing

efforts, 2009

y Hoyt Clarke Hottel Award by the American Solar Energy Society (ASES) award committee

for outstanding educator and innovator in the field of photovoltaics, 2009y Thought Leadership Award finalist by the Aspen Institute's 2009 Energy & Environment

Awards, 2009

y Climate Protection Award by the U.S. Environmental Protection Agency (EPA) for dedication

and technical innovation in PV, 2009

y One of The Five Most Influential People in Renewable Energy by Power Finance & Risk

Magazine, 2008

y Georgia Institute of Technology Outstanding Research Program Development Award, 2007

y William Cherry Award by the IEEE Photovoltaic Specialists Conference, 2003

y Rappaport Award by the U.S. Department of Energy/NREL, 2003

y Georgia Tech Distinguished Professor Award, 1996

y As part of the 1996 Olympic Games in Atlanta, Dr. Rohatgi and his team designed and

installed the world's largest grid-connected, roof-top PV system on the Georgia Tech Aquatic

Center

y Westinghouse Engineering Achievement Award, 1984

Rohatgi received a B.S. degree in Electrical Engineering from the Indian Institute of Technology,

Kanpur, in 1971, and a M.S. degree in Materials Engineering from the Virginia Polytechnic Institute



Now, in research being reported in the journal Proceedings of the National Academy of Science

(PNAS), Nocera, along with postdoctoral researcher Mircea Dinc? and graduate student Yogesh

Surendranath, report the discovery of yet another material that can also efficiently and sustainably

function as the oxygen-producing electrode. This time the material is nickel borate, made from

materials that are even more abundant and inexpensive than the earlier find.

Even more significantly, Nocera says, the new finding shows that the original compound was not a

unique, anomalous material, and suggests that there may be a whole family of such compounds that

researchers can study in search of one that has the best combination of characteristics to provide a

widespread, long-term energy storage technology.

³Sometimes if you do one thing, and only do it once,´ Nocera says, ³you don¶t know -- is it

extraordinary or unusual, or can it be commonplace?´ In this case, the new material ³keeps all the

requirements of being cheap and easy to manufacture´ that were found in the cobalt-based

electrode, he says, but ³with a different metal that¶s even cheaper than cobalt.´

But the research is still in an early stage. ³This is a door opener,´ Nocera says. ³Now, we know what

works in terms of chemistry. One of the important next things will be to continue to tune the system,

to make it go faster and better. This puts us on a fast technological path.´ While the two compounds

discovered so far work well, he says, he is convinced that as they carry out further research even

better compounds will come to light. ³I don¶t think we¶ve found the silver bullet yet,´ he says.

Already, as the research has continued, Nocera and his team have increased the rate of production

from these catalysts a hundredfold from the level they initially reported two years ago. In addition,

while the earlier paper and the new report focus on electrodes on the oxygen-producing side,

originally the other electrode, which produced hydrogen, included the use of a relatively expensive

platinum catalyst. But in further work, ³we have totally gotten rid of the platinum of the hydrogen

side,´ Nocera says. ³That¶s no longer a concern for us,´ he says, although that part of the research

has not yet been formally reported.

The original discovery has already led to the creation of a company, called Sun Catalytix, which aims

to commercialize the system in the next two years. And his research program was recently awarded

a major grant from the U.S. Department of Energy¶s Advanced Research Projects Agency - Energy.

F rank Dimroth, F raunhofer Institute for Solar Energy Systems ISE

Following his undergraduate degree in Zurich, Frank Dimroth began doctoral studies at theFraunhofer ISE in the area of experimental physics and received his Ph.D. in 2000 at the University

of Constance. Very early on, he was successful in the field of semiconductor epitaxy, and in 2007 he

was named manager of the group "III-V Epitaxy and Solar Cells," a group currently with 50

employees. At 39, he is the author of around 120 scholarly articles and the holder of nine patents for

photovoltaic cells. He has supervised numerous undergraduate theses and doctoral dissertations in

the area of photovoltaics. With Dr. Andreas Bett, department head and deputy director of Fraunhofer



ISE, he has been a driving force in the area of highly efficient III-V multiple-junction solar cells and

concentrator photovoltaics over the past ten years. In 2005 the two researchers were involved in the

establishment of Concentrix Solar GmbH, a spin-off of the Institute. The company produces

concentrator photovoltaic systems and has recently installed its first concentrator solar power plant

in Spain.

Notably, Dimroth also recently won the ³Fondation Louis D´ award, the highest-endowed award

presented in France for achievements in science, specifically for the metamorphic triple-junction

solar cell which has a record efficiency of 41.1%. "I am extremely pleased for my team and the entire

Institute in light of this outstanding research prize and the international recognition it brings for our

work," Frank Dimroth stated. "This prize shows us once again that we are on the right track toward

developing solar technologies. Concentrator systems have the potential to supply Southern Europe

with low-cost solar electricity in a matter of just a few years. With our work we are tackling an

important task for the future."

A multi-junction solar cell is created with the aid of processes similar to those used in thesemiconductor industry. "Our work involves a modern epitaxial process known as metal organic

vapour phase epitaxy," Dr. Dimroth explained. The process involves successively depositing solar

sub-cells on top of each other on a substrate of germanium. The result is a wafer-thin solar cell

structure just a few m thick, with a well-hidden complex inner structure of up to 50 monocrystalline

layers. With the development of metamorphic crystal growth, Frank Dimroth and his colleagues have

made it possible to use a larger range of III-V compound semiconductors to grow multi-junction solar

cells. This makes the solar cells better adapted to the spectrum of wavelengths found in sunlight.

To date, multi-junction solar cells have been used in space technology to supply satellites with

energy. To tap into the high potential efficiencies for regenerative power generation here on earth,Frank Dimroth and his colleagues came up with a special design: They developed a photovoltaic

concentrator module that uses Fresnel lenses to concentrate solar radiation by a factor of 500 onto

triple-junction solar cells only 3 mm2 in area. This reduces the costly semiconductor surface area

required and makes III-V multi-junction solar cells for electricity generation an attractive alternative in

regions rich in direct sunlight. Prof. Eicke R. Weber, Director of Fraunhofer ISE, is convinced: "We

expect that high-efficiency concentrator technology - in addition to photovoltaics using crystalline

silicon and the classic thin-layer technology - will become established as a third technology for cost-

efficient generation of solar electricity in the sunny regions of the world."

When asked to describe the major trends in the photovoltaics/solar power industry today, Dimroth

said it was a difficult question to answer. ³I am not even sure if there is one major trend in the PV

industry except for the unbroken strategy to grow fast and to prove that PV can cover a substantial

part of our energy need,´ he said. ³Cost reduction by further integration, scaling and growth is still

the main driver in this industry. A movement towards utility scale installations in the MW power range

is certainly a trend which can be observed. With the major drop in PV system prices over the last

years, competition has been growing in most of the market segments putting pressure on innovation



(especially through the Euro-CIS breakthrough in the early 90s, his remarkable combination of

device and material and general technology knowledge and ideas, make him the central figure in the

coming of age of CIGS as a serious thin film solar cell option. His work laid the basis for many a

company that is now pursuing CIGS technologies and did so on a global scale.´

Schock recently received the ³Becquerel Prize´ following his plenary lecture on ³The Status and Advancement of CIS and Related Solar Cells´. The first pioneer tests on chalcopyrite-based solar

cells took place under his direction as early as 1980, and were to make solar energy more efficient

and more competitive.

At present, Hans-Werner Schock¶s group is researching new material combinations of abundant,

environmentally friendly chemical elements and is continuing to refine solar cells based on these

materials. The solar cells developed at HZB under Hans-Werner Schock¶s leadership hold several

efficiency records: CIS cells in the high-voltage range (12.8%), flexible cells made from plastics

(15.9%) and conventional CIGSe cells (19.4%). The aim is for ³solar cells to be integrated into

buildings, for example, no longer as an investment, but as a matter of course,´ says Schock.

The ³Becquerel Prize´ was first awarded in 1989 on the occasion of the 150th anniversary of

Becquerel¶s classic experiment on the description of the photovoltaic effect. With it, French physicist

Alexandre Edmond Becquerel laid the foundation for the use of photovoltaics.

Ely Sachs, 1366 T echnologies, Inc.

Emanuel ³Ely´ Sachs is the Chief Technical officer of 1366 Technologies Inc, a company he founded

together with Frank van Mierlo. The goal of 1366 is to make silicon solar cells cost competitive with

coal generated electricity.

Ely Sachs is also a Professor at MIT, specifically the Fred Fort Flowers and Daniel Fort Flowers

Professor of Mechanical Engineering at MIT. Dr. Sachs is totally focused on PV for his research and

he supervises a growing PV research group at MIT. The group is currently pursuing projects in wafer

fabrication, surface texturing for light trapping, metallization, and light trapping at the module design

level. He also aims to drastically reduce the cost of wafer manufacturing through a new

groundbreaking kerfless wafering technology called Direct Wafering.

Sachs is the inventor of "String Ribbon," a ribbon crystal growth process for making low cost

substrates for solar cells, which is now being commercialized by Evergreen Solar, Inc. of Marlboro,

MA.

Sachs co-invented Three Dimensional Printing, a manufacturing process for the creation of 3D parts

directly from a computer model in layers. 3D Printing is being commercialized in fields-of-use

including appearance models, ceramic molds for castings, direct metal tooling, end-use metal parts,

medical devices, and pharmaceuticals.



Sachs is also known for work in the area of Process Control of VLSI fabrication and is a co-inventor

of a plasma etch diagnostic tool now commercially available.

Sachs is the author or co-author of more than 110 technical papers and is the inventor or co-inventor

of more than 40 patents. Sachs was a Hertz Foundation Fellow and earned the Hertz Foundation

Doctoral Thesis Prize in 1983 for his work on String Ribbon.

Rajendra Singh, Clemson University

Rajendra Singh is the D. Houser Banks Professor & Director, Center for Silicon Nanoelectronics,

Holcombe Department of Electrical and Computer Engineering, at Clemson University in Clemson,

SC. He said he remembers back to 1973 during the days of oil embargoes when he decided to do

his PhD thesis on Solar Cells. ³The vision I had in 1980 is happening only now, 30 years later,´ he

said. ³The economic crisis of 2008, followed by recession or low economic growth in developed

economies and high growth in emerging economies, has changed the landscape of energy business

all over the world,´ he noted. That motivated him to write a book, titled ³Sustainable Energy for for Sustained Growth of Developed and Developing Economies.´

In his, Singh says he has examined ³every energy source and other than free fuel based PV and

wind there is no other solution. Due to inherent advantages, PV will take over wind and eventually

we will have PV as the dominant electricity generation technology. In our lab, we are also working on

solving electrical energy storage problem by the use of solid state capacitors based on giant

dielectric constant materials. Once we have the solution of electrical storage problem, virtual vertical

integration of the entire PV industry coupled with co-location of all component manufacturers and

ultra large scale PV manufacturing (Giga watt and higher scale) in a single location, PV generated

power will be cheaper than any other energy conversion technology. Thus the day is not too for

when PV as a solid state device will play the same role what CMOS has done for the world of today

that is based on global economy,´ he said.

The major trends Singh sees today is that the PV industry will continue to grab more and more share

of electricity generation throughout the world. ³Large scale solar farms will continue to dominate the

PV electricity generation and roof top PV will be only in the range of 25-30%,´ he said.

Singh said the most difficult technical challenge is to solve the electrical storage problem. ³Once we

have solved the problem of electrical storage (cost less than $0.25 per watt), ultra large scale PV

manufacturing and virtual vertical integration of PV industry can provide installed PV systems

(~minimum 5-10 MW systems) cost of about $2 to $2.50 per watt. At this price in addition to the

market of developed economies, there is a huge market of some 2.5 billion people who are forced to

rely on biomass -- fuel wood, charcoal and animal dung -- to meet their energy needs for cooking.

Providing clean energies to these 2.5 billion people by PV will create a market that will make PV

industry as big as electronics industry (~$1.5 trillion per year),´ he said.



The major economic/policy/regulation challenges facing the photovoltaics industry moving forward?

³The challenges are different for developed and emerging economies,´ Singh noted. ³For developed

economies the driving force is the job creation, energy security and reduction of carbon emission.

For emerging economies (China and India particularly) providing energy to meet the goal of 8-9 %

growth per year is the main issue. Throughout the world, financing PV projects is the most difficult

problem. Nuclear energy is not economical for any country and no more new nuclear reactors should

be constructed. However, in many parts of the world nuclear is still being considered as an option for

future generation of electricity. Due to the policies supported by various governments, investors do

not see the role of PV (free and clean fuel) as it should be in the 21st century. Current financing

mechanisms are inadequate to bring large sum of money in PV business. Policies need to be

created for flow of large capital in PV industry. Utilities should be forced (by legislation) to use more

and more PV (on an incremental basis) and the value of peak power generation must be recognized

throughout the world,´ he said.

Dan Arvizu, NREL

Dr. Dan Arvizu has been the director and chief executive of the U.S. Department of Energy's (DOE)

National Renewable Energy Laboratory (NREL) since January 15, 2005. NREL, in Golden,

Colorado, began operations in 1977 and is the DOE's primary laboratory for energy efficiency and

renewable energy research and development. NREL is operated for DOE by the Alliance for

Sustainable Energy, LLC (Alliance). Dr. Arvizu is President of the Alliance and also is an Executive

Vice President with the Midwest Research Institute, headquartered in Kansas City, Missouri.

After more than three decades of professional engagement in the clean energy field, Dr. Arvizu has

become one of the world's leading experts on renewable energy and sustainable energy. In the past

three years, he has testified before Congress four times, given state-of-technology presentations atthree Congressional caucus briefings, and keynoted 12 major national and international

conferences. As NREL's Director, he has established and implemented a new institutional strategy

to position the lab for higher impact and contributions to national energy challenges. In the past three

years, he has overseen an increase of more than 50% in the lab's operating budget and has helped

attract over $400M for new infrastructure.

In 2004, Dr. Arvizu was appointed by President Bush for a six-year term to serve on the National

Science Board, which is the governing board of the National Science Foundation and the national

science policy advisory body to the President and Congress. He chairs the Audit and Oversight

Committee and is the co-chair of the task force on "Building a Sustainable Energy Future: U.S.

Actions for an Effective Energy Economy Transformation."

Arvizu serves on a number of boards, panels and advisory committees including:

y American Council on Renewable Energy Advisory Board

y Energy Research, Development, and Deployment Policy Project Advisory Committee at the

Harvard Kennedy School

y Singapore Clean Energy International Advisory Panel



y Hispanic Engineer National Achievement Award Corporation

y Colorado Renewable Energy Authority Board of Directors

y Intergovernmental Panel on Climate Change Working Group III -- where he is currently

serving as a coordinating lead author on a special report on renewable energy.

Prior to joining NREL, Dr. Arvizu was the chief technology officer with CH2M HILL Companies, Ltd.Before joining CH2M he was an executive with Sandia National Laboratories in Albuquerque, New

Mexico. He started his career and spent four years at the AT&T Bell Telephone Laboratories.

ting Martin Green, University of New South Wales

Martin Green (born 1948) is an Australian professor at the University of New South Wales (UNSW),

where he is focused on the development of solar energy. He was born in Brisbane and was

educated at the selective Brisbane State High School, graduated from University of Queensland and

completed his PhD on a Commonwealth Scholarship at McMaster University in Canada, where he

specialized in solar energy. In 1974, at the University of New South Wales, he initiated the Solar Photovoltaics Group which soon worked on the development of silicon solar cells. The group had

their success in the early 80s through producing a 20% efficient silicon cell, which now has been

improved to 25%. e has published several books on solar cells both for popular science and deep

research, and has been recognized with different awards. He also serves on the Board of the

Sydney-based Pacific Solar Pty Ltd. (now known as CSG Solar), as Research Director.

Among the major awards won by Green: Pawsey Medal (Australian Academy); Award for

Outstanding Achievement in Energy Research; IEEE Cherry Award; CSIRO External Medal; IEEE

Ebers Award; Australia Prize (1999); Gold Medal from the Spanish Engineering Academy; Medal of

Engineering Excellence for Distinguished Achievement in the Service of Humanity from the World

Engineering Federation (Hannover, 2000); Millennium Award from the World Renewable Congress;

Right Livelihood Award; Karl Böer Solar Energy Medal of Merit Award from the University of

Delaware; Finalist, European Inventor of the Year (together with Stuart Wenham); Winner, 2008

Scientist of the Year Award; 2009 Zayed Future Energy Prize finalist.

Arvind Chel, Energy F orum

Dr. Arvind Chel is the president of the Energy Forum and a Senior Research Scholar at the Centre

for Energy Studies in New Delhi, India. The major trend that he observes is that the PV industry is

growing rapidly in both ceveloped and developing countries. ³Developed countries had already setup

grid connected PV systems since the cost of electricity in developed countries is much higher

compared to developing countries like in India due to subsidy on coal based power generation,´ Chel

said. Solar electricity prices are today around 30 cents/kWh, which is 2-5 times the average of

residential electricity tariffs in developed countries. ³Through the Jawaharlal Nehru National Solar

Mission in India, solar photovoltaic stand alone systems are going to be installed in large scale all

over the part of India. Water pumping, solar street lights are becoming popular in many places in

India both in government as well as the private sector. Cost of PV system has come down to 4.17



dollar/Wp or 4.11 Euro/Wp in August 2010 as compared to 27 dollar/Wp in 1982. The PV module

cost is around 50 - 60% of the total installed cost of a solar PV system. Therefore the solar module

price is the key element in the total price of an installed solar PV system. All prices are exclusive of

sales tax depending on the country or region can add 8-20% to the prices, with generally highest

sales tax rates in Europe,´ he said.

Chel says that, currently, BIPV systems have received wide attention from SolarFrameWorks BIPV

CoolPly system install at New England Patriot Place. The BIPV CoolPly system simultaneously cools

the roof and cools the solar modules in the summer. In the winter, the system provides additional

insulation preventing heat loss while optimizing power production to promote optimal power

production and energy conservation in commercial buildings.

Training and human resource development is another challenge for PV industry. Formulation of PV

module standards considering the life time problems and quality output issue with age of PV

modules.

The opportunity for photovoltaics is to identify a technology that eliminates the cost, product and

manufacturing challenges of existing inorganic approaches - while creating new capabilities. Current

inorganic materials have challenges including:

y Difficult and expensive to manufacture

y Limited substrate options - heavy glass or stainless steel

y Limited basic materials - some environmentally unfriendly like Cadmium

y Limited aesthetic options - black or blue only

y Heavy and cumbersome "picture frame" support elements

y

Extremely fragile.

The major economic/policy/regulation challenges facing the photovoltaics industry moving forward?

³Sales tax depending on the country or region can add 8-20% to the prices of PV modules which is

highest in Europe can act as barrier for PV technology penetration. New subsidization regulations

can make this industry sustain its market demand. The interplay between incentives and policy

support on the hand and technology cost point reductions through industry innovations and scale will

determine how PV industry grow in developing countries like India,´ he said.



Figure 1. Rigid solar module with silicon cells.

In developing a solar product, the operative word is designed-in, for many of the key components

that make up a particular module ² bus bars, contacts, blackout/protective film, back sheet

laminate, junction box attachment, wiring, packaging, or array interconnections ² depend on the

proper selection, conversion, and assembly of materials. Often the design process is complex, and

at times, custom materials must be developed and tested.

Role of the materials converter

A materials converter takes volume materials and converts them into finished parts for an end

product. In the case of solar, such parts include foil tapes slit to specification for bus bars, thermal

conductors and insulators, electrical insulators, adhesives for bonding layers, die-cut parts on

production rolls, foam tapes and precision cast foams, edge seals and edge delete tapes, and a host

of other materials that are cut, shaped, and formed to meet design and assembly requirements for

solar modules, or panels.

Figure 1 is a diagram of a rigid solar module with rigid silicon PV cells. Shown are the parts and

materials incorporated in an average assembly. Figure 2 is an illustration of a representative thin film

product. The actual materials used for a given application depends on the design of the module. In

Figure 2, for example, the specification may require that a blackout material be applied to the face of

the glass to prevent pre-energizing of the cells. On the other hand, where solar activation is not a



concern, a clear protective film may be called for instead. The choice of a particular back sheet

material ² usually a laminate ² may vary with the application as well.

Figure 2. Rigid solar module with thin-film cells.

The trend toward thin film is a boon for solar manufacturers. Whereas a manufacturer may be ableto turn out 100 rigid silicon modules a day, the same manufacturer ² with the bulk of the

engineering and materials supplied by a converter ² may be able to produce as many as 4,000

modules during the same timeframe based on thin film technology.

Materials converters who serve the solar industry are distinguished by the added services they offer

and the degree of involvement with customers above and beyond the production of parts that meet

particular manufacturing and performance specifications. For example, they often participate with

their customer in the design and development process to ensure the specification of materials and

parts that result in the most functional and cost-effective solution for the application. In such

instances, the knowledge of the converter is brought to bear with regard to the performancerequirements of the materials and manufacturing capabilities of the solar manufacturer. Depending

on the material, specifications may include temperature resistance; performance at upper

temperature limits; shear, tensile, and peel strength; outgassing; dielectric strength, thermal

conductivity; slitting widths, and tolerances. For example, typical requirements may include

temperature resistance of 180°C with an upper limit of 200°C; peel adhesion of 37 oz. per inch; Z

axis resistance of 56mohms; and shielding effectiveness of 80dB to 95dB from 1GHz to 18GHz (Fig.

3.)



For the converter, maintaining a state-of-the-art test facility is necessary as well. The facility enables

testing to governing specs ² typically UL specifications 1703 and 746, as well as others, in the U.S.

² not only to confirm incoming materials supplied by vendors, but also to certify that performance

specs are met by the materials and parts being delivered to the solar manufacturer. For global

applications, customers may mandate UL specs as well. IEC standards may also apply to ensure

both performance and safety in the design and manufacture of solar modules.

Converters are sometimes called upon for independent third-party testing services. In these

instances, the end user either lacks the capability to perform particular tests or is looking to meet

deadlines with offsite support. Occasionally, the end user wishes corroboration of results obtained

in-house.

In introducing a new material to a given process, the converter may choose to retain the proprietary

rights to the product, or may release the rights to the end user. In some instances, converters create

proprietary materials and composites in anticipation of a future need or application or to achieve a

performance or cost objective.

Ongoing research is also devoted to developing improved materials for existing end user

requirements. In such instances, where a notable advancement has resulted and been validated

through qualification testing, the end user may decide that performance improvements outweigh the

cost of changing production.

Optional services

While converters tend to concentrate on materials engineering and on producing sub-assembly

products that meet end user specifications, some companies offer extended services at the end of

the development cycle. Some converters also offer prototyping, production-run manufacturing, and

final assembly services, such as kitting and inventory control.



In addition to selecting the right materials, a converter can often help the solar panel manufacturer

by discovering how to process unique materials by customizing the manufacturer's process or

equipment. Using the converter's materials processing knowledge can help a manufacturer gain a

competitive advantage and cost-effectively handle a unique material.

Conclusion

Converters play an essential role in the manufacture of solar panels. Such companies are more than

parts manufacturers inserted between the supplier of materials and the manufacturer of the solar

panels. Not only do converters produce the parts needed to assemble a module, but they also often

participate in initial materials engineering. Many converters also have the capability to develop

materials to meet unique physical and performance requirements. They are also capable of

performing testing services that check incoming materials as well as products being delivered to

customers.

Most materials converters are problem solvers as well, from coming up with interleaf materials for flex panels to specifying foam tapes ² some exceedingly thin ² that stick under changing

environments with factors such as moisture, temperature, and vibration, while providing the desired

dielectric performance. Converters must also be aware of contamination, which can come from

many sources, not just the environment.

As third generation solar modules become an increasing challenge for manufacturers, especially

with the inroads being made in concentrator technology, converters will be called upon not only for

design and materials development and testing to ensure compliance with governing standards, but

also to provide expertise and support to optimize costs, minimize rejects, and meet manufacturing

schedules. Only with that level of assistance can solar cells evolve to the point of competing with, as

opposed to augmenting, conventional methods of power generation.

Rick Traver received his Bachelor's degree in business administration from California State U. and

is a technical field representative at Fabrico, 4175 Royal Drive, Suite 800, Kennesaw, GA 30144

USA; ph.: 678-202-2700 ; [email protected]

Solar and Energy Storage - A PerfectMatchBy John Battaglini, International Battery and Michael F. Reiley, Wailuku, HI | October 19, 2010 |



Stabilizing the Grid

While wanting more energy produced by renewables, managing its generation is an issue. The Maui

Electric Company (MECO), like other utilities across the islands, has expressed great concern about

renewable power sources posing a threat to overall grid operations. Intermittent power takes time to

ramp up and can go offline on cloudy or still days. This situation causes the utilities to boostproduction sporadically. Therefore, energy storage can directly impact grid stabilization, lessening

peak demands and providing back-up power during power outages.

According to the Energy Storage Council, the Department of Energy (DOE) estimated in 1993 that

energy storage could have a $57.2 billion positive impact from the widespread use of "high-density

storage devices to« store power during off-peak periods and deliver it when loads exceed

generating capacity." The Council has since updated this forecast to $175 billion over the next 15

years. Interestingly, Japan and Europe far outpace the U.S. in energy storage with 15% and 10%,

respectively. The U.S. falls way behind with just 2.5%; the U.S. is playing catch-up, but not for long.

Putting Energy Storage to the Test

Recently, utilities and system integrators in the U.S. have initiated several demonstration pilot

programs to prove the viability of energy storage and its potential impact on the grid. Besides grid

stabilization and load leveling, storage systems can potentially provide back-up power to thousands

of residential and commercial customers, especially when solar or wind is not available.

Figure 2. International Battery's lithium ion technology is ideal for high-power ramp up/down and power smoothing applications. Battery systembehaved very well under 3C conditions.



Another key driver for energy storage is the renewable portfolio standard (RPS) adopted by states in

order to significantly increase the amount of electricity generated by renewables. According to the

DOE, as of May 2009, there are 24 states plus the District of Columbia that have RPS policies in

place. Together, these states account for more than half of the electricity sales in the United States.

The state of Maine has an aggressive goal of 40% by year 2017. California wants to reach 33% by

2030, and many other states want to reach between 15% and 20% in the next five years and

beyond. And as mentioned earlier, Hawaii has an aggressive mandate of 70% from renewables by

2030.

As an example, the Maui Economic Development Board (MEDB) recently wanted to assess the

effectiveness of storing solar energy. International Battery teamed with solar integrator HNU Energy

in Maui to develop a solar power generation and energy storage system for the MEDB (Fig. 1). HNU

Energy has become a leader in Maui's rapidly growing green economy and specializes in

commercial and residential photovoltaic systems as well as high efficiency LED lighting. Working as

a team, a renewable energy system for the MEDB was developed and is comprised of sixty 224W

photovoltaic panels, a bi-directional three-phase inverter system, and a state-of-the-art charge-controller network provided by HNU Energy. In addition, a 48V, 16.4kWh lithium-ion-based energy

storage system was integrated - complete with battery management and controls - to store the

energy generated from the solar array.

The energy storage system includes four battery modules, totaling 32 160Ah lithium iron phosphate

(LFP) cells and a battery-management system (BMS) that is integrated into a standard Electronics

Industry Alliance (EIA) style 19" portable rack mount chassis and enclosure (Fig. 2). The large-

format lithium ion batteries were chosen because of their proven high-energy density, robust thermal

and cycling performance, as well as easy system expandability.

The success of the MEDB project has garnered attention from a wide group of Hawaii renewable

energy stakeholders including national labs, utilities, the PUC, and multi-megawatt scale solar and

wind providers. Ramp up/down and power smoothing are of special interest for bringing large

renewables onto the grid without destabilization. These applications require high power and energy

with the ability to discharge the batteries at rates that are multiples of the battery capacity (C-rate).

Lab data, shown in Fig. 2, demonstrates the ability to meet a 5MW ramp up/down requirement of

three and five minutes, respectively. A single battery charge handled multiple ramp up/down cycles.



Figure 3. HNU Energy's grid management graphical user interface (GUI).

The keys to overall system performance are knowing the health and charge state of the individual

battery cells, as well as understanding the temperature, depth of discharge and charging status.

HNU Energy engineered an interface between the grid and International Battery's BMS, providing

maximal flexibility to transition seamlessly between being grid-tied and off-grid. Figure 3 illustrates agraphical user interface (GUI) developed by HNU Energy to remotely monitor and control the BMS

and grid interface. Voltage and temperature for every battery can be remotely monitored and

controlled. Load balancing and power smoothing are continually optimized to ensure grid stability

and maximum battery service life.

Community Energy Storage Project

Another future outcome of the Smart Grid is community energy storage (CES). Coined by the utility,

American Electric Power, CES is part of the utility's gridSMART demonstration project. This project,

funded in part by $75 million DOE stimulus funding, will be deployed to 110,000 AEP customers in

northeast central Ohio. The idea is to provide the utility and its customers many benefits, including

load leveling, back-up power, support for plug-in electric car deployment, and renewables as well as

grid regulation and improved distribution line efficiencies.

As part of this first-of-its-kind project, AEP and system integrator, S&C will test large-format lithium

ion batteries (Li-Ion). Different from their smaller counterparts used in flashlights and IPods, large-

format lithium ion prismatic batteries (Fig. 3) provide the right-size building blocks to deliver higher



amounts of energy and scale up as energy demands increase. Of course, controlling and

understanding the state of the batteries is vital, and that's where highly intelligent battery

management comes in to play. Using state-of- the-art software and electronics, today's advanced

battery monitoring systems can tell users the exact state of the battery, state of health, charging

status and temperature. This project is currently underway and will integrate a broad range of

advanced technologies in the distribution grid, utility back-office and consumer premises with

innovative consumer programs. The outcome is to demonstrate the many benefits of a Smart Grid

for consumers and the utility. In fact, CES holds the promise of becoming an integral component of

the smart grid.

The Need for Efficient, Scalable Energy

As the Smart Grid transforms associated industries, the role and significance of energy storage will

continue to increase. And, while there are different storage solutions such as flywheels, compressed

air and hydro as well as various battery technologies, large-format lithium ion cells are leading the

way in many high energy applications because of their near 100% efficiency, scalability andversatility. The energy storage market made huge strides during 2009. Of the $185 million granted

from the DOE for 16 projects, $83.1 million was allocated to 11 battery-related projects.

Conclusion

Energy storage systems need to be robust and dependable. Today's advances in battery

technology, combined with superior methods of monitoring and managing batteries, take energy

storage to a much higher level of integration in smart energy applications. From an economic and

environmentally sustainable perspective, the future looks bright for the combination of renewables

with energy storage - a perfect match.

Acknowledgment

gridSMART is a sales mark of American Electric Power.

John Battaglini received his MBA from Villanova U. and an MS in electrical engineering from

Clemson U. and a BS in electrical engineering from Drexel U. and is VP of Business Development at

International Battery, 6845 Snowdrift Road, Allentown, PA 18106 USA; ph.: 610-366-

3925 ; [email protected]

Michael F. Reiley holds a BS in physics, an MS in optics and a PhD in electrical engineering and isthe President of HNU Energy, 1765 Wilapa Loop, Wailuku, Hawaii; ph.: 808-244-

7844 ; [email protected]



Solar Power R eliability and Balance-of-System DesignsBy Mike Fife, P.E., PhD, PV Powered Inc. | October 14, 2010 | 1 Comment

Balance-of-system component providers can significantly reduce the levelized cost of energy

by boosting device reliability.

Tulsa, Oklahoma, USA -- In order to compete more effectively with other energy sources, the solar

industry is focused on decreasing the levelized cost of energy (LCOE), a term that refers to the price

at which solar energy is valued taking into account all the lifetime costs of the solar power system.

This includes the cost of the initial investment, the cost of capital, the cost of system operations and

maintenance and repair costs. While there is much visibility on bringing down the purchase cost of

solar cell technologies, the cost of maintenance and repairs represents the major variable cost over

the lifetime of a photovoltaic (PV) system. In fact, although PV balance-of-system (BOS)

components (inverters, trackers, junction boxes, combiners and transformers) represent only about

10 percent of system costs, they have historically been responsible for up to 70 percent of system

failures.1,2,3,4 Fixed cost and downtime associated with these failures can have a significant

negative impact on solar power economics.

One of the most effective things that BOS component providers can do to help bring down the LCOE

is to increase the reliability of their devices in solar plant applications. Such a program needs to start

with an analysis of where failures can occur.

Sources and Likelihood of Failure

Some pioneering work to improve reliability was done by PV Powered Inc. in partnership with Boeing

on a project funded by the U.S. Department of Energy (DOE) under the Solar America Initiative

(SAI). As part of the project, a Boeing engineer performed a system-level failure analysis of a 10 MW

plant. A mathematical model of the whole plant was constructed using reliability data provided by the

component manufacturers for each subsystem (inverters, disconnects, fuses and so on).5 The model

takes into account the estimated probability of failure of all components and the estimated cost and

time to make repairs when a component fails.



Time to repair is a key element of the equation because it is directly related to calculating the

amount of energy lost during the outage. In some cases, the cost of lost energy production can far

outweigh the cost of the failed components.

It is well known in reliability engineering that equipment typically goes through three phases duringits fielded lifetime. A complete system-level failure analysis needs to take into consideration multiple

failure types. For example, one type of failure is "infant mortality" for which the probability of failure±

as the name implies±decreases with time as shown in the traditional "bathtub curve" (see Figure 2).

Random failures, such as those due to lightning strikes, have the same probability of occurring at

any time in the system's life. Finally, the probability of wearout failures, such as those due to contact

oxidation or moving parts wearing out, increases with time.

Because the probability of failure of the system as a whole increases with each component, the

number of parts in the system is a major variable contributing to system reliability. It stands to reason

that, all other things being equal, systems with fewer components will be more reliable than thosewith more components. And in this regard, there's a balance between adding devices that can

contribute to increasing the energy harvest and the contribution that the additional devices make to

increasing the chance of failure. For example, DC-DC converters placed between the arrays and the

inverters are being promoted as a way to increase power output from the arrays. But the additional

system components must be factored into the reliability equation. A similar observation can be made

regarding solar tracking systems that adjust the arrays for maximum irradiation.



For their part, inverter manufactures have different design philosophies resulting in different

component makeups and hence different reliability profiles for their products. Therefore, just asdeveloping a reliability model for a solar power system involves taking into account the reliability

profile of each system element, calculating the reliability of a particular system element (such as a

solar inverter) requires constructing a reliability model of each of its components. Some components

may be specially selected to withstand harsh environments and some may incorporate redundancy

so that a failure will not affect the operation of the system as a whole.

The operating environment that solar equipment is typically subjected to poses particular challenges

to component reliability. To accurately predict component stresses and associated wear-out

mechanisms that solar system electronics experience due to natural temperature cycles, a complex

time-dependent thermal modeling approach is required. This type of modeling allows component

temperature changes to be simulated over a long time period in a particular environment.

To accomplish this, factors such as solar heating, conduction and convection to and from each

component must be considered. Any active cooling system control parameters must also be

considered since they can affect component temperatures by, for example, turning on a fan.

Therefore, many component temperatures do not track ambient conditions, but instead follow a more

complex pattern that is a function of ambient temperature changes, geometry of the inverter power

profile and cooling control system setpoints. There are a number of methods that can be used to

perform thermal simulations. The preferred method at PV Powered is a custom Matlab program that

solves the heat transfer equations (convection, conduction and heating rate) given an input file

containing a set of component properties, thermal interaction parameters and cooling control lawparameters.

In calculating long-term component reliability under changing temperature conditions, simpler

constant-hazard-rate and mean-time-between-failure (MTBF) calculations that might apply in other

situations are not applicable. More advanced techniques such as cumulative damage modeling can

be used, however.



Improving Inverter Reliability

Because of the complexity of the problem and the need to optimize the results, PV Powered started

with a clean sheet of paper in designing its commercial and utility-scale inverters. The resulting

designs employ between 30 percent and 50 percent fewer components compared to other inverter

designs. With fewer components to fail the projected uptime of the system can be extended

accordingly.

Another contributor to the PV Powered inverters' reliability is a redundant cooling system. The

design principle behind this is to use a single airflow source with redundant fans that allow the

inverter to continue to operate at full power if one should fail. Variable fan speed control is used to

deliver the necessary amount of cooling air to assure long-term component reliability, but no more,

thus minimizing fan power and maximizing fan lifetime. Fan speed, energy use and temperatures are

remotely sensed and alerts and faults are generated if problem conditions occur. High capacity air

intake filters are used to keep entire inverter clean.

Protection against random events that affect solar system reliability is also a design consideration.

For example, lightning strikes have been found to be a significant cause of inverter damage. PVPowered exceeds recommended lightning protection measures internal to the inverter by

incorporating dual redundancy and failure detection. But lightning protection needs to be approached

from a system perspective and requires much more than just internal protection. Standards such as

IEC 62305 can be used as a guide for establishing system-level protection of PV systems from

lightning strikes.



Validating System Reliability

The theoretical reliability projections for solar system components can be validated through testing.

Two types of testing are performed at PV Powered: Accelerated life testing of designs can improve

reliability as part of the qualification process and stress screening is performed during production

testing to screen infant mortality defects. Accelerated life testing is performed by operating invertersat elevated stress levels chosen to rapidly and quantifiably accelerate degradation mechanisms.

Stress screening, also called burn-in, is performed at maximum inverter operating temperatures

under careful monitoring for abnormalities.

The most important thing that solar power component and system designers can do is understand

potential failure modes that can arise so that designs may be produced that minimize the chances of

those failures occurring. And by increasing the reliability of solar power systems, we're able to

decrease system downtime, which is a major contributor to the levelized cost of energy.

1. E. Collins, et al., "Reliability and Availability Analysis of a Fielded Photovoltaic System," 34thIEEE Photovoltaic Specialists Conference, Philadelphia, Penn., USA, June 2009

2. H. Laukamp, ed., Task 7 Report International Energy Agency IBI-PVPS 77-08: 2002,

"Reliability Study of Grid Connected PV Systems Field Experience and Recommended

Design Practice," Fraunhofer lnstitut fur Ware Energiesysteme, Freiburg, Germany, March

2002

3. N.G. Dhere, "Reliability of PV modules and balance-of-system components," Photovoltaic

Specialists Conference, 2005. Conference Record of the Thirty-first IEEE , vol., no., pp.

1570-1576, 3-7 Jan. 2005

4. L. M. Moore, and H. N. Post, "Five Years of Operating Experience at a Large, Utility-scale

Photovoltaic Generating Plant," Progress in Photovoltaics: Research and Applications, 20075. Russell W. Morris, and John M. Fife, "Using Probabilistic Methods to Define Reliability

Requirements for High Power Inverters," Proceedings of the SPIE vol. 7412 74120G-2, 2009

Dr. J. Michael Fife is director of Reliability for PV Powered. He has more than 15 years of experience

in technology development and failure analysis. His experiences include managing engineer at

Exponent Inc. and aerospace research engineering roles at the Air Force Research Laboratory

Electric Propulsion Group and NASA Dryden Flight Research Center. He is a licensed professional

engineer and holds M.S. and Ph.D. degrees in Aeronautics and Astronautics from MIT and a B.S.

from Texas A&M University

Superconducting SeaTitan Opens up aNew Path to 10 MW By Martin Fischer, AMSC Windtec | October 12, 2010 | 1 Comment



Superconductor generators represent a breakthrough in offshore wind energy economics,

with considerable weight and efficiency advantages as well as the tantalising prospect of

improved reliability.

Klagenfurt, Austria Installed wind generation capacity is currently doubling about every three years.But even greater growth is now foreseeable as high capacity offshore turbines of 10 MW or greater

start to become available.

Due to the development of such higher capacity wind energy systems, market forecasts for the

nascent offshore industry have been revised dramatically upwards. The industry, which accounted

for just 2 GW of the world's total 158 GW of wind power installed at the end of 2009, is expected to

enter a period of rapid and prolonged growth beginning mid-decade. For example, industry research

firm Emerging Energy Research currently projects that global offshore installed capacity will increase

to approximately 20,000 MW by 2015 and rise sharply to 104 GW by 2025.

Until now, the greatest challenges to developing offshore wind have included the practical size and

weight limitations of the wind turbine generators, gearboxes and blades, which must be transported

over roadways and then erected hundreds of feet in the air.

The power density advantage of superconductor wires, however, is now being applied to the wind

industry, offering an optimal solution to maximising the 'power per tower' for wind turbines, while also

overcoming size and weight barriers ² and reducing costs. With the ability to produce 10 MW of

power or more per tower, American Superconductor Corporation's (AMSC) SeaTitan promises to

be among the world's most powerful wind turbines.

The Next Target Application for Superconductors

SeaTitan's ability to maximise the power output per tower structure is facilitated by the elimination of

copper from the generator's rotor and the use instead of high temperature superconductor (HTS)

rotors. This enables the generator to be much smaller, lighter, more efficient and less expensive

than conventional large-scale wind turbine generators. Efficiency is further enhanced ² and

manufacturing and maintenance costs kept down ² by using a direct drive system, thus eliminating

the complex turbine gearbox, which tends to be the most maintenance-intensive component.

AMSC's wholly owned Austria-based subsidiary AMSC Windtec has developed proprietary wind

turbine designs that are utilised by more than a dozen manufacturers worldwide, including two of theworld's top 10 wind turbine manufacturers. The company has also long been the leader in the

superconductor arena ² producing superconductor wire that can carry 150 times more power than

conventional copper wire ² and holds the world's deepest patent portfolio for superconductor

rotating machines such as motors and generators.



Having invested over US$150 million in large superconductor rotating electric machines over the

past two decades, a dramatic pay-off occurred in 2009 when the company completed full-power

testing of an HTS motor designed for the US Navy.

Conducted at the US Navy's Integrated Power System Land-Based Test Site in Philadelphia, testing

of the world's first 36.5 MW (49,000 horsepower) HTS ship propulsion motor doubled the Navy'spower rating test record. Designed and built under a contract from the Office of Naval Research to

demonstrate the efficacy of HTS motors as the primary propulsion technology for future Navy all-

electric ships and submarines, Naval Sea Systems Command (NAVSEA) funded and led the testing

of the motor.

This 36.5 MW superconductor ship propulsion motor by AMSC and Northrop Grumman is the basis

of the SeaTitan

This same base platform is now being utilised for the HTS generators that will be at the heart of the

SeaTitan wind turbines. These systems have been demonstrated to have as little as half the

electrical losses of a conventional machine when at full power.

Superconductor generators additionally offer higher efficiencies than conventional machines over

their full range of operation while delivering lower lifetime ownership costs, due in part to their

enhanced reliability and improved Mean Time Before Failures (MTBF) figures. The HTS generator

technology is also planned to be applied to onshore wind turbines to offer the same power density

advantage.

Vast Potential Driving Interest in Offshore Wind

A key attribute of offshore wind energy is the fact that it is a large, and virtually untapped, clean

energy resource. Offshore winds are typically stronger and more stable than onshore, resulting in

significantly higher production per installed turbine. The North Sea, for example, has average wind

speeds up to 12 m/s, but these winds are often located far from the coast.

These resources might be exploited in the future with the development of floating turbine

foundations. Closer to the British coast, the wind speed falls to 8 m/s, about the average speed for a

good onshore project. Offshore wind also offers a range of other advantages:



Only fundamentally new approaches to turbine design, such as the SeaTitan, will achieve these

goals.

Design Characteristics and Projected Benefits

The hub height of the SeaTitan HTS turbine is approximately 125 metres with a tower top diameter of 5 metres and a tower base diameter of 7 metres. The tubular steel tower can rest on conventional

jacket foundations and deep-water foundations of various types. Technology, in conjunction with the

HTS generator, is what sets this design apart from existing generators, however.

As turbine sizes approach 10 MW and beyond, other types of direct drive generators, such as

permanent magnet and synchronous machines, get larger in diameter and weight, thus making them

more expensive to integrate in comparison with HTS technology. Direct drive generators, in

particular, obviate concerns over the effect of deflections in the main shaft since they do not

influence gear-to-gear contact and are compensated for by free movement in a large air gap.

Furthermore, vibrations set up by tooth engagement are eliminated, and lower rotational speedsreduce load cycles.

An artist's impression of the 10 MW SeaTitan machine from AMSC



AMSC Windtec, which provides licences and customised designs for onshore and offshore turbines,

anticipates licensing the new SeaTitan technology to multiple manufacturers. Benefits include:

High turbine power density: The HTS field winding produces magnetic fields higher than those of

conventional machines resulting in much smaller size and weight.

High partial load efficiency: HTS generators have higher efficiency at part load that results in apotential efficiency advantage of 10% or more at low speeds.

Low noise: HTS generators have lower sound emissions than conventional machines.

Harmonics: HTS generators have better power quality and in particular are free of harmonics.

Maintenance: In addition to negating the need for a gearbox, direct drive HTS generators will not

require the generator rotor overhaul, rewinding or re-insulation that is required with conventional

generators.

Simple mainframe: No decoupling between generator stator and mainframe housing is needed,

because rotor deflections are effectively absorbed by the large air gap.

Increased personal safety: The HTS generator rotor can be demagnetised during wind turbine

maintenance or potential wind turbine repairs. This significantly increases the personal safety of service employees compared to wind turbines with permanent magnet generators.

The weight savings attributable to HTS technology allows the generator to be placed directly above

the tower, enabling improved mainframe design and direct load transfer from hub to tower.

In most existing offshore wind turbines, a major failure mode is caused by the deflections of the rotor

shaft, which occur under turbulent wind conditions. To reduce damage, the housing of the gearboxes

or generators are decoupled from the mainframe in a complex way. This is not needed in an HTS

generator, because the large air gap can absorb all likely deflections, and the generator housing can

be directly integrated into the wind turbine mainframe.

This, combined with the small generator diameter, is the primary contributor to the strength and yet

the light weight and comparatively small size of the SeaTitan design. Furthermore, the HTS design

model requires only a single main bearing configuration as additional gearbox and generator

bearings are not required.

In addition, conventional permanent magnet generators require grease for the bearings and

tightening checks on fasteners, while conventional doubly-fed induction generators require cleaning

and replacement of brushes on the slip ring.

AMSC has incorporated a number of design solutions that ensure redundancy in the SeaTitan's

operation. In particular, the cryogenic cooling system must be as robust and reliable as possible so

that customers are not involved in additional services or maintenance. The refrigeration system

achieves high reliability by employing n+1 modular, single-stage GM coolers and long-life seals in its

helium transfer coupling.



In AMSC's experience with cooling transfer systems in both HTS transmission and large rotating

machines this component has presented excellent reliability in all cases. In addition, AMSC's design,

which uses more than one cryogenically cooled surface, promotes efficiency and ease of

maintenance. First, more than one cryogenically cooled surface in series allows each section to work

less to lower the temperature of the cryogenic fluid. Also, if one cryogenically cooled surface

malfunctions, the redundancy in the system is designed to be able to overcome the loss.

The refrigeration system additionally has no unusual environmental requirement or impact due to the

required cryogenic cooling components for an HTS generator. In fact, most serviceable components

are placed in the tower bottom for easier access and faster exchange. These accessible

components include power converters, the compressors for cryogenic cooling, the control cabinet,

and switchgear.

The Path Ahead for the Wind Industry

Maximising the potential of offshore wind power sites will require new technical approaches inturbine design to increase power density, reduce weight and lower maintenance costs. HTS

technology, having been proven in large ship propulsion motors and in many other electric utility

applications, is clearly one way to achieve these goals.

The SeaTitan will apply novel generator rotor technology and superconductor generator

technology to reduce system size and weight and lifetime costs. Ultimately, significantly lower

offshore wind development and maintenance costs will result from such developments. Indeed, the

SeaTitan HTS generator represents a path forward to achieve wind generator power ratings in the

10 MW range and beyond.

Martin Fischer is vice president of American Superconductor, general manager of AMSC Windtec

Exploring the secrets of superconductor technology

The basic HTS wire substrate is nickel tungsten. Various buffer layers are then applied before the

superconductor ² yttrium barium copper oxide ² and a very thin cap layer of silver are also

applied.



Superconductor wire alongside conventional copper equivalents

The winding is then cooled to an operating temperature of 30²40°K or around -235°C.

Compressors for the rotor refrigeration system represent a heat load which is about 0.4% of the

machine rating or some 40 kW for the SeaTitan. Nonetheless, the overall losses from the generator

(including the refrigeration units) are 40% less than those in conventional direct drive generators.

And there are significant advantages in terms of power density. For example, a 10 MW 10 rpm direct

drive PMG would be 10²12 metres in diameter. An HTS generator with an equivalent capacity will

be 4.5 metres in diameter.

At present the overall project is managed out of the company's AMSC Windtec division in Klagenfurt,

Austria, and generator development is being conducted at facilities in Devens, Massachusetts, US.

The company is in active discussions with test centres both in North America and in Europe to

perform the design testing and the intention is to commercialise these wind turbines by 2014 or

2015. This, of course, would require complete prototype testing prior to that.

Meanwhile, AMSC has recently announced an investment in advanced blade technology at Blade

Dynamics, which provides a potential blade platform for the SeaTitan. AMSC Windtec is also lining

up the other parts of the supply chain that would be needed for these wind turbines, like the towers,

foundations and nacelle.



Solar Array Design: Parallel WiringOpens New DoorsBy Michael Lamb, VP, Business Development, eIQ | August 30, 2010 | 20 Comments

The advent of parallel wiring architectures for solar arrays promises to create new levels of

freedom and flexibility for designers.

Tulsa, Oklahoma, United States -- For decades, designers of solar power systems have faced a

knotty set of interlocking challenges. Solar panels produce DC at relatively low voltages, but

inverters require a relatively high input voltage to be able to convert the power to AC and send it to

the grid. Solar panels can be wired in series to sum their voltages, but their combined output

fluctuates with even small mismatches among panels on a string.

Striking a balance between these factors is traditionally one of the grand challenges of solar power

system design and also a significant element in determining whether a given location is suitable for a

solar installation in the first place. However, today new doors are being opened by innovators in a

vibrant technology-driven industry and the advent of parallel wiring architectures for solar arrays

promises to create new levels of freedom and flexibility for designers.

Series: The Old Way

Series-wired systems are governed by the principles of voltage. A solar array must provide a high

enough voltage to enable its inverter to operate at an efficient level; this has traditionally requiredseries wiring, so that panel voltages sum. Similarly it is important to make sure that the system can

never go above the maximum voltage permitted by code, usually 600VDC in the U.S.

However, the inverter is sensitive to operating voltage levels. It can suffer major swings in efficiency

when the input voltage varies in relation to its fixed output voltage. The larger the variation, the

harder it is for the inverter to operate at optimal efficiency. Currently inverter efficiency is shown at a

single operating point when actual operating efficiency varies as system voltage changes, real

operating efficiencies can be off several percentage points from the optimal operating efficiency.

To accommodate these physical demands, all series-architected solar installations must abide by a

set of design rules. The result of these rules is to define the minimum-sized building block (string)

used for a given installation. Once this is defined, that exact footprint must be used for the entire

array. This can lead to serious challenges, as designers are forced to manage the always-unique

geometry of the proposed array location. In many cases, these challenges translate into increased

cost of deployment, smaller system sizes or even a decision to forego the installation completely.

The New Parallel Solar Universe



The enabling technology for parallel solar deployment is a new generation of low-cost, high-

efficiency electronic devices that allow a solar module to deliver a fixed DC voltage to a DC power

bus. This DC power bus can be set to the single best point for the inverter or can float to whatever

level the inverter requires, allowing the inverter to concentrate simply on optimizing its AC-to-DC

conversion efficiency, as opposed to worrying about what compromises it might need to make to

effectively harvest power from the solar modules. This mechanism provides an effective transport of

power to a central inverter where AC conversion efficiencies can be optimized.

In this parallel solar paradigm, the PV technology of the module no longer matters, as each module

operates with complete independence from its neighbors. Because each module can produce the

voltage level needed by the inverter, voltage summing with strings of modules is not needed. This

means that a solar array can now be designed and installed just like a lighting system. Each module

represents a current source and as long as the array¶s wiring is sized appropriately and its branches

are capable of handling the current produced, the system will work at optimum efficiency; no other

design rules apply.

What does this mean to the system designer? The biggest advantage is that systems can be built

using variable-sized blocks of modules ranging from 200 watts to 31,000 watts. This enables

designers to maintain installed cost targets while also taking complete advantage of all available

space at an installation site. If the geometry or aesthetics of a project require multiple azimuth

angles, different angles of tilt or shading, there is no longer a need to incur the costs or design

limitations of multiple inverters. The solar power system can accommodate the architecture of the

building, rather than requiring the building architecture to provide an ideal platform for the solar

array. Different PV module technologies can even be applied to a single inverter (that is, thin film

and crystalline).

But this new technology also allows us to think a little further out of the box. We now have a new tool

available for optimizing a system¶s production capabilities in multiple environments. We are only

scratching the surface of what we can achieve with this new capability. For example, rather than

using a technology like a tracker, we might use different materials technologies to optimize

production across multiple seasons and environmental conditions.

Mathematics of Parallel Solar Power System Design

Parallel solar design reduces the number of variables that need attention during solar power system

design. Voltage is no longer a factor, so Voc overhead and temperature drift are no longer concerns.

We are also freed from worry about the NEC 600V upper limit and its restrictions on the number of

modules we can wire together. This simplifies the calculation of wiring loads.

Three basic decisions must be made at the outset: size of the installation in kWh, modules to be

used and inverter to be used. With these in mind, we can start to envision the system. As an

example, let¶s consider a 180 kW building block using 30 kW units with 230 watt solar modules

operating at a Vmp of about 40 VDC. The math here is simple: we will need about 132 modules



(30,000/230 Ãâà 132). We will assume that the inverter¶s peak efficiency point is at about 330 VDC.

From this, we can calculate that at maximum power output, we will have to deal with 92 Amps of

current into our inverter (132 modules × 230W/330V = 92 amps (P/V=I)).

Thinking about this as a lighting circuit, we can look at using six branches of 15 Amps each, a

conservative level for #10AWG PV USE-2 or RHW-2 cable outside of conduit. Each branch wouldhave an inline 20 Amp fuse connecting it to a #4 AWG PV backbone that runs directly into the

inverter through a 125 Amp fused DC disconnect.

We can also go a bit larger and design a parallel solar power system for 500kW production capacity:

module power density, 230 W; voltage input to the inverter, 330 VDC; total power capacity of

system, 550,000 W.

This will tell us the number of modules we want to use: Total System Capacity/Module Power

500,000/230 = 2,174 modules.

To figure the total current the system will need to manage we take the total power and divide it by

the voltage. Modules×Module Power in Watts = System Power. System Power/Voltage to Inverter =

Current. Thus, 2,174×230/330 = 1,516 Amps.

From here it is a simple matter of working out the number of branches needed to manage the current

flow. If we assume use of three of our 180 kW building block circuits (506 Amps each) to connect to

our inverter, we can place their terminating points close to the array to minimize our use of conduit. If

we want to minimize our terminations, we could use #4 AWG PV wire into our building block

combiner units, with each handling 85 Amps.

To minimize I2R losses we can take a conservative approach and use 20-Amp in-line fuses

harnessed into the #4 AWG PV backbone, giving us six branches using #10 AWG PV. Each of our

three combiners then will have 167kW of power concentrated into a single pair of conductors,

handling a total run of 506 Amps into the central inverter. This array would need just six physical

field terminations at the combiners, and six at the inverter. If the combiners are placed strategically

at the edge of the array, the conduit runs would likewise be limited to three: one from each combiner

to the inverter (see figure 1, below).



The difference between parallel and series architecture for solar power system design is as simple

as the difference between current and voltage. In a series system, the voltage of the module drives

the design and therefore the economics of the installation. Parallel wiring lets the voltage be set as a

constant, which allows the system to be driven by current.

Current is a much easier variable to work with on several levels. First, it is a familiar, well-understood

design variable for designers and installers; the same one used in all lighting system design.

Second, the current variable is much easier to regulate and control with existing safety systems.

Third, we can optimize the efficiency of the DC-to-AC conversion by regulating the operational

voltage of the solar array to the voltage of the grid that the system is providing power to.

Perhaps most importantly, parallel solar wiring allows different PV technologies to feed a single

inverter. This promises to open new vistas for architects and system designers as they search for

better ways to integrate solar technology into our everyday lives. It will allow PV manufacturers tooptimize products for very specific environmental conditions without having to carry the load of an

entire system¶s production capacity. It may also make new materials more feasible by isolating each

module from the rest of the system, allowing it to work at whatever native voltage is most efficient for

that particular technology. All of these new possibilities open the door for innovation in the solar

market.

renewable mix infra structure

Documents