ict and power (electricity) prof. rahul tongia school of computer science cmu 17-899 fall 2003

ICT and Power (Electricity)

Prof. Rahul TongiaSchool of Computer Science

CMU17-899 Fall 2003

Rahul Tongia, CMU 2

Topics for Discussion Electricity and Development Power for ICT ICT for Power

Rahul Tongia, CMU 3

Fundamentals Electricity is a form of energy (kWh) Does not exist in usable forms

Conversion usually requires prime movers (steam turbines, water turbines, etc.)

Access to fuels (primary energy) is a key issue for developing countries

Electricity is only about 125 years old Widespread use is much more recent

US required special programs Rural Electrification Administration (REA) [now Rural Utilities

Service] TVA

Electricity from the grid can not be easily stored (AC) Most electronics use DC

Rahul Tongia, CMU 4

What’s Special about LDCs?

Very low levels of Electrification 2 billion+ lack electricity Bad quality, intermittent, and often expensive power if

available Lower Level of Economic Development

Large rural agricultural sector Large quantities of crop residues: primary energy source Special needs for agricultural services (e.g., pumping water ~

1/3 of India’s electricity) Heavily subsidized in many countries

Industrial-Political Organization State-centered economies

State-owned enterprises (SOEs) handle not just power but much of the economy

Weak formal institutions E.g., regulatory institutions, courts, corporate governance

Rahul Tongia, CMU 5

Energy-Economy Correlation

1

10

100

1000

10000

1 10 100 1000 10000 100000Primary Energy (Trillion BTU)

GD

P (

Bil

lio

n $

)

North America

Developing

W. Europe

FSU/E. Europe

OECD Asia/Pacific

China

USJapan

Turkmenistan

Russia

India

Brazil

Germany

New Zealand

Mexico

South Korea

Australia

Bangladesh

Pakistan

1996

Calculated from EIA Data

Rahul Tongia, CMU 6Source: WEO 2002

0

100

200

300

400

500

600

700

800

900

1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 2025 2030

Peo

ple

wit

ho

ut

Ele

ctri

city

Acc

ess

(mill

ion

s)

(Lack of) Access to Electricity

East Asia (China)

Sub-Saharan Africa

South Asia (India)

Rahul Tongia, CMU 7

Investments in LDC Power Sector

Source: World Bank (2003)

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Where Does Electricity Go? US

~ 1/3 residential, 1/3 industrial, 1/3 commercial Developing Countries

Varies significantly by country Typically higher shares for non-residential (function of large,

centralized design) Grid penetration to rural areas is very low

Kenya used to have more homes served by Decentralized Generation (DG) than the grid (mainly solar)

In reality, a fair amount is lost along the way, or stolen!

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Electricity in LDCs

Source: World Bank (2003)

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How Much Electricity Does ICT Use? Numbers as high as 13% of US

electricity were claimed End users, servers, networking, etc. Later debunked

ICT – Energy (Power) linkages Greater Service Economy, even in

developing countries But, increased globalization


What Consumes Power (ICT Applications)? Components of an ICT solution

Computing Display

CRT 80 W normal 10 W suspend LCD 15-25 W normal 5-10 W suspend

Storage variable Uplinking 12 W Wifi 40 W VSAT

Role of advanced technologies Chips (processor is largest component)

Pentium 4 uses 50+ watts! LCD screens, OLEDs, etc. Wireless

Cognitive Radios – reduce power to lowest required level But, emitted power is << power drawn from supply

100 mW is legal limit for WiFi Laptops – much less power but less robust (?)


Details of Desktop Power AGP video card - 20-30W PCI video card - 20W AMD Athlon 900MHz-1.1GHz - 50W AMD Athlon 1.2MHz-1.4GHz - 55-65W Intel Pentium III 800MHz-1.26GHz - 30W Intel Pentium 4 1.4GHz-1.7GHz - 65W Intel Pentium 4 1.8GHz-2.0GHz - 75W Intel Celeron 700MHz-900MHz - 25W Intel Celeron 1.0GHz-1.1GHz - 35W ATX Motherboard - 30W-40W 128MB RAM - 10W 256MB RAM - 20W 12X or higher IDE CD-RW Drive - 25W 32X or higher IDE CD-ROM Drive - 20W 10x or higher IDE DVD-ROM Drive - 20W

SCSI CD-RW Drive - 17W SCSI CD-ROM Drive - 12W 5400RPM IDE Hard Drive - 10W 7200RPM IDE Hard Drive - 13W 7200RPM SCSI Hard Drive - 24W 10000RPM SCSI Hard Drive - 30W Floppy Drive - 5W Network Card - 4W Modem - 5W Sound Card - 5W SCSI Controller Card - 20W Firewire/USB Controller Card - 10W Case Fan - 3W CPU Fan - 3W

Source: FLECOM


Standalone (DG) Power What are the options if If AC power is unavailable?

Backup or primary supply? Non-Conventional Sources of Power

Issues of Scale For ICT or more (single point or village level)?

Local availability Solar

Only 3-5 hours equivalent per day (1 kW INPUT/m2 of panel; ~10% efficiency) Wind

Windspeeds vary by location; highest efficiency for megawatt class turbines Biomass

Conversion options limited, typically require tens of kW size Microhydel

Location sensitive, and typically 10s of kW Diesel

Expensive to run, typically AC output


Designing a DG system Battery Life examples

Alkaline (from Duracell)NOMINAL VOLTAGE (volts) RATED CAPACITY (ampere-

hours)D 1.5 15C 1.5 7.8AA 1.5 2.85AAA 1.5 1.15

Gets very expensive, quickly, even if rechargeable Lead-acid batteries give much more power and are standardized

Limits on dischargeability - ~20 kWh total charge Matching supply to demand

AC grid – “infinitely” flexible Power storage is key

Else peak capacities must be matched Intermittency issues for many DG systems

Theft is a major concern for DG design (!)


Designing a DG system (cont.) Solar Systems

Components PV modules (in series, in panel form) Power Conditioning Equipment (economies of scale) Housing (with or without directionalizing)/mounting Batteries – most expensive operating costs* Inverter – if AC is required

Costs Capex at small scale is ~5/peak watt Gives an operating cost around 20-30 cents/kWh

* cell phone example – Obsolescence of equipment vs. battery


Designing a DG system (cont.)

Hours per day operational 12Days back-up required 3 (1 current day plus 2 days of no sun)

Power needs 50 Notebook PC20 Communication15 Lighting15 Other*

100 Watts AVERAGE

3,600 W-hrs required to charge up per day

Equivalent peak sunlight 5 hrs per day

System size calculation 720 peak watts5 $/peak watt

3,600 $ Capex

Sizing - 1 meter panel 1,000 W input (peak)10% efficiency (net)100 W electricity out (peak)

Thus need 7.2 sq. m panel


ICT for Electricity Systems Two main issues

Supply << Demand Requires investments of billions

Ability to pay is limited Often, power companies are loss-making; some of

that is inefficiency Where can ICT contribute?

Components of power sector vertical Generation Transmission Distribution Consumption


Conventional Wisdom One can not do real-time power flow

management (transactions and billing) for transmission level flows Today, pools operate based on historical or

aggregated information One can not measure demand (usage) from

all consumers in real-time with high granularity

What has changed to make these outdated – the growth of IT technology


Focus here on Distribution/Consumption IT is already extensively used in

generation/transmission in developed countries

Other Synergies Stringing Optical Fibers along power lines Smart Cards (pre-payment)

Found extensive use in S. Africa in Black Townships (12 years experience)

Can link to other utilities or consumer services (pre-paid cell-phone cards are very popular)


Using IT to Enable Sustainability

Sustainability has many components Resource utilization

Efficiency and loss reduction are sine-qui-non Economic viability

Theft reduction Management

IT can improve power sector distribution, consumption (utilization), and quality of service Requires a change in mindset, and the

willingness of utilities to innovate


Case study on IT for power sector improvement in India India today has the world’s largest number

of persons lacking electricity 400 million (equivalent to Africa’s unserved!)

Reforms began in 1991 Vertically integrated government department

monopolies are being broken Initial focus was on generation New realization that distribution is the key to

India’s power sector viability Newer entities should be run as businesses

Many parallels to other developing countries


India’s Power Sector Overview

5th largest in the world – 107,000+ MW of capacity But, per capita consumption is very low

350 kWh, vs. world average over 2,000 kWh 40% of households (60% of rural HH) lack electricity

In very dire straits Supply << Demand

Blackouts are common, with shortfall estimated between 10-15% Most utilities are heavily loss-making, with an average rate of

return of negative 30% or worse (on asset base) High levels of losses = 25+%

Technical losses – poor design and operation Commercial losses (aka theft) often over 10%


Reasons for the problems Agricultural sector

Consumes 1/3 of the power, provides <5% of revenues Pumpsets are overwhelmingly unmetered – just pay flat

rate based on pump size Adds to uncertainty in technical losses vs. commercial losses

and usage Utilities lack load duration curves to optimize

generation and utilize Demand Side Management All generation is assumed to be baseload, and priced

accordingly Leads to poor energy supply portfolio

Doesn’t send correct signals to consumers, either Utilities end up using just average costing numbers, not

recognizing the marginal costs


Idea – use IT for power sector management Posit – If new meters are to be installed,

why not “smart” digital meters, which are also controllable, and communications-enabled? Incremental costs would be low

Instead of just quantity of power, can also improve quality of power

Analysis presented is based on collaborative work with a major utility in India (name withheld for confidentiality reasons)


Quality of Power India is focusing on quantity of power only

Current “shortfall” numbers are contrived Based only on loadshedding with minor correction for frequency Do no factor in peak clipping fully Do not account for lack of access (e.g., over 60% of rural homes lack

connections) Quality norms are often missed

Voltage – often deviates by 25+% Frequency – often deviates by 5% (!)

Even farmers pay a lot for their bad quality power (around 1 cent/kWh implicit, even higher in some regions)

Use of voltage stabilizing equipment Additional capital costs (in the multiple percent range) Efficiency losses (2-30% lost!)


Power Quality: ITI CBEMA Curve


Why the Focus on Distribution? It’s where the consumer (and hence, revenue) is High losses today

Technical losses, 10+ % in rural areas DSM and efficiency measures possible Use of standards required

Use a combination of technology, industrial partnership, and regulations

Learn from experiences elsewhere Bulk of India's consumption is for just several classes of

devices Pumpsets Refrigerators Synchronous motors Heating (?)


US Refrigerator Efficiency Standards

Similar standards can be established for “smart appliances”

Source: www.standardsasap.org


Future of Appliances and Home Energy Automation Networks

Incremental cost of putting networking and processors into appliances approaching a few dollars Could allow time of use and full control (utility

benefit/public good/user convenience) Link to a smart distribution system

Micro-monitor and Micro-manage every kWh over the network E.g., refrigerators – don’t operate or defrost during peaks (5% of

Indian electricity usage) 5% peak load management could lead to a 20% cost reduction

Feasible, as most peak loads are consumer-interfaced Bimodal peaks in India, residential driven

Italy is already implementing such a system (ENEL)


Objectives and design goals for a new IT-enabled Implement a basic infrastructure to…

Micro-measure every unit of power across the network Allow real-time information and operating control Devise mechanisms to control the misuse and theft of

power through soft control

Which would… Reduce losses Improve power quality Allow load management Allow system-level optimization for reduced costs Increase consumer utility, satisfaction, and willingness to

pay


Additional Benefits A system which will offer

Outage detection and isolation Remote customer connect & disconnect Theft and tamper detection Real time flows

To allow real time pricing Suitability for prepayment schemes Load profiling and forecasting Possible advanced communications and services

Information and Internet access Appliance monitoring and control

Managing such “extra” power (from theft) is enough to give subsistence connectivity to the poor

Requires ICT to determine and manage the margin effectively Telecom is special – very short-run low marginal cost; in electricity it is

much more difficult

Access(440, 220, or 110 V)

Low Voltage

Smart Meter(Can be off-site outside user

Control; Is partly a modem)

Secondary

Distribution

Voltage

House

House

Users

Distribution(~11 kV)

Medium Voltage

Couple

r

Coupler

Coupler

~ 20 km Last Few Hundred Meters

Substation

Data Center

Distribution Transformer

(pole or ground)

Coupler

Sub-Transmission and Transmission

(> 11 kV)

LV Concentrator

Network Schematic

Uplink


Components of the solution

One segmentation – locational At consumer

Meter/Gateway Meter could be pole-side if required

In home network Needed connect to enabled devices (appliances) Eventually, homes would also have Decentralized

Generation available (?fuel cells, flywheel storage, etc.)

Access (low voltage distribution) From gateway to a concentrator, on user side of

distribution transformers – Using PowerLine Carrier (PLC)


Solution Components (Cont.)

Concentrator upwards Concentrator – Each Distribution Transformer (aka

Low Voltage Transformer) feeds on the order of 100-200 homes in India (as in Europe). In contrast, US Distribution Transformers feed 5-10 users.

Communications medium Over Medium Voltage PLC to the Sub-station

or Wireless

Limited Coverage in Developing Countries Substation upwards (uplinking)

Usually based on leased lines or optical fiber


Technologies for various segments In-Home Network

Appliances Emerging Standards are talked about by appliance

companies (Maytag, Samsung, GE, Ariston etc.) Using Simple Control Protocol (or other appropriate “thin”

protocols) Meters

Solid-State meters exist, but not yet the norm in developing countries

Most have communications capabilities for external ports

Lowest cost solution (if feasible) – PLC – target 5$ incremental cost


Technologies for various segments (cont.) Access

Low Voltage PLC is available today Being explored for Internet access, in fact

(Megabits per second) MV

Crossing through transformers remains a technical challenge

Going long distances an issue Uplinking

Availability of optical fiber or leased lines can be met through planning


Technologies vs. Capabilities

Accuracy Theft Detection

Communications Control Capabilities

Electro-mechanical Meter

low (has threshold issues for low usage)

poor expensive add-on nil

Digital (solid state)

high Node only external Limited Historical usage reads

only

Next Gen. Meter (proposed)

Arbitrarily high

High (network

level)

Built-in (on-chip)*

*Can do much more than Automated Meter Reading (AMR)

Full (connect/dis-

connect); Extending

signaling to appliances

Real-Time control; DSM


Design Model and Business Case Only target specific users

All agricultural (almost one-third of the load) All Industrial and larger commercial users Only the larger-size domestic users

Estimated 2/3 of homes only use <50 kWh per month Include every network node that needs

monitoring and/or control Substations Transformers Capacitor banks Relays

etc.


Design Model and Business Case (cont.) Investment in long run only a few thousand

rupees per targeted user (Target <75$ capex) When amortized, implies requirement of

improvements in system of only a few percent! Savings will come from

Lower losses/theft Increased sales possible Lower operational costs Load management Better consumer experience (and hence, possibility for

higher tariffs) Future interaction with smart appliance and smart home

networks Possibly new services


Economics of case system

Estimated System (Rural-centric)

62 Consumers (all classes) per Distr. Transformer

98 Distribution Transformers per Sub-Station

Number of Nodes Equipment cost ($) Cost ($)Domestic (applicable) 200,000 75 15,000,000 Commercial 383,000 75 28,725,000 Agricultural 673,000 75 50,475,000 High-TensionDistribution Transformers 70,306 500 35,153,000 Substations 714 5,000 3,570,000

132,923,000 Other IT and infrastructure (capitalized) 10,000,000

142,923,000 15% <-annualized rate incl. Amortization

Needed Savings 21,438,450$ annually

11,625,000,000 kWh sold annually0.06 Electricity Rate ($/kWh) <- Average only;

697,500,000$ Annual CostsExcludes peak

3.1% <- Need improvements worth savings potential


Economics (cont.) 6-7 year payback on investment

(conservative) possible with just 3% improvement in system

Savings will come from Theft Reduction Time-of-Day and DSM measures (peak

reduction) System Quality, reliability, and uptime Higher Collection


Challenges Protocols

Use of thin protocols to reduce capex for embedded systems Security – PLC can be a shared medium

PLC How to couple around transformers or other obstacles How to go long runs with low errors (and high enough bandwidth) –

Shannon’s theorem provides a limit Noisy line conditions in many developing countries

Appliances Need for standards to bring down costs and ensure inter-operability

Design – Should the PLC signals pass through the meter/gateway directly to appliances?

How active or passive should consumer behavior modification be?

Costs (as always)


Challenges – Implementation and Management Utilities are typically risk-averse They face increased regulatory uncertainty

Without some portions of a market, how do they benefit?

Will they (should they) pass all pricing information on to the consumer?

Developing country management issues Utilities were typically State Owned Enterprises (SOEs) Utilities were run with social engineering goals

Increased automation, control, and sophistication (and theft detection) poses risks to the large cadre of current employees


A New World for Power Systems Includes “smarts” for significant

improvements in efficiency New services can be enabled once the

appropriate infrastructure is in place Segmentation of development allows

independent, modular innovation, e.g., home automation and appliances

Developing countries (esp. Asia) can lead the way through leap-frogging

ict and power (electricity) prof. rahul tongia school of computer science cmu 17-899 fall 2003

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