OCEN 201Introduction to Ocean &

Coastal Engineering

Renewable Marine Energy (2)Jun Zhang

jzhang@civil.tamu.edu

2

Cost of Ocean EnergyCost of Ocean Energy

<Carbon Trust Report, 2006>

2

3

Status of Ocean Energy TechnologiesStatus of Ocean Energy Technologies

Demonstration scale

Cost estimate from

20-75cents/kWh for WEC and 5-

30cents/kWh for TEC. More realistic

estimation may be at its high end

More Research is needed not more

hype

Current Status Design and Maintenance:

1) Robustness and efficiency of

energy generator

2) Corrosion and survivability

3) Economics

Environmental impacts: ecology

(e.g. Shiwa tide power plant)

Transmission: Integration into the

grid (intermittent energy generation

and long distance)

Storage of Energy

Issues

Water Program Restarted in FY 2008

FY07 FY08 FY09 FY10 Recovery Act

$0M $10M $40M $40M - $60M? $32M

Appropriations address both conventional hydro (CH) and marine and hydrokinetic technologies (MHK)

Recovery Act focused on conventional hydropower for short-term impacts

Technology Definitions

Marine and Hydrokinetic (MHK): energy from:• Waves• Water currents (tides, rivers, ocean currents, man-made channels)• Ocean thermal energy (OTEC)

Program Areas and FundingProgram Areas and Funding

Ocean Energy Development in USOcean Energy Development in US

(Courtesy of Mr. Hoyt Battey, US (Courtesy of Mr. Hoyt Battey, US DOE)DOE)

Technology Development: Address technical barriers to device design, development, testing, and integration Market Acceleration: Address non-technical barriers to development, siting, and deployment

Marine & Hydrokinetic TD, $15.55,

41%

Marine & Hydrokinetic MA, $10.44,

28%

Conventional Hydro TD, $4.10, 11%

Program support, $2.66,

7%

Conventional Hydro MA, $4.86, 13%FY2009 Water Budget $37.6M

FY09 Water Budget AllocationFY09 Water Budget Allocation

Development in US

• System Deployment and Testing

– Facilitate the deployment and testing of full scale MHK prototypes and components

– Support the development of integrated test centers

– Generate data on performance, reliability and impacts

• Cost Reduction and System Performance/Reliability

– Support design and development of scale systems and components

– Develop design and testing protocol, support developers who follow it

• Understand Environmental Effects

– Collect/disseminate data on environmental impacts to reduce deployment costs and environmental effect

• Resource Assessments

– Determine the available, extractable, and cost-effective water resources in the US

• Develop Evaluation and Performance Standards

– Characterize, evaluate and compare the wide variety of MHK technologies; continue IEC/IEA standards development

MHK Program PrioritiesMHK Program PrioritiesDevelopment in US

FY2008 MHK ProjectsFY2008 MHK Projects Technology Development Projects

2008 Funding Opportunity Announcement, Topic Area 1: Advanced Water Power Renewable Energy In-Water Testing and Development Projects

– WaveConnect Wave Energy In-Water Testing and Development Project (Pacific Gas & Electric Company)

– Development and Demonstration of an Oscillating Water Column (OWC) Power System (Concepts ETI, Inc).

– Improved Structure and Fabrication of Large, High-Power Kinetic Hydropower Systems and Rotors (Verdant Power Inc).

– Puget Sound Tidal Energy In-Water Testing and Development Project (Snohomish County PUD)

– Advanced Composite OTEC Cold Water Pipe Project (Lockheed Martin)

– Northwest National Marine Renewable Energy Center (OSU/UW)

– National Marine Renewable Energy Center in Hawaii (U of Hawaii)

Development in US

FY2008 MHK ProjectsFY2008 MHK Projects Market Acceleration Projects

2008 Funding Opportunity Announcement, Topic Area 2: Marine and Hydrokinetic Renewable Energy Market Acceleration Projects

– Guidelines for Developers and a Framework for Siting Marine and Hydrokinetic Energy Projects (Pacific Energy Ventures, re vision, PCCI)

– Wave Resource Assessment (Electric Power Research Institute -- EPRI)

– Tidal Resource Assessments (Georgia Tech Research Corporation)

– International Standards Development for Marine and Hydrokinetic Renewable Energy (Science Applications International Corporation)

Report to Congress: Potential Environmental Effects of Marine and Hydrokinetic Energy Technologies

International Energy Agency, Ocean Energy Systems (IEA-OES) Annex IV, Assessment of Environmental Effects and Monitoring Efforts for Ocean Wave, Tidal, and Current Energy Systems

Jobs and Economic Development Index (JEDI) modeling

Development in US

FY2009 Funding OpportunitiesFY2009 Funding Opportunities

Industry-led Projects

Topic Area 1: MHK Energy Conversion Device or Component Design and Development

Topic Area 2: MHK Site-specific Environmental Studies and Information

Topic Area 3: Advanced Water Power Market Acceleration Projects/Analysis and Assessments

Laboratory-led Projects

Topic Areas 1 & 3: Supporting Research and Testing (MHK, CH)

– Computational tools/models to predict device/array behavior; advanced materials, device testing and validation codes

Topic Areas 2 & 4: Environmental Assessment and Mitigation Methods

– Tools and studies to predict, evaluate, and minimize environmental impacts

Development in US

Barriers and Actions to OvercomeBarriers and Actions to Overcome

Despite the increased interest and research and development activities, ocean energy technologies remain high risk and at an early stage of development.

Several technical and non-technical barriers are currently restricting development of ocean energy technologies.

–Lack of sufficient demonstration of prototypes in the marine environment

–Cost of connecting ocean energy systems to electricity networks impacts on demonstration projects

–Lack of understanding on environmental impacts

–Absence of internationally recognized standards for development, testing and measurement

Ocean energy technology could contribute to meeting cost-effective, sustainable and secure energy demands in the long term provided governments and device developers act to overcome the barriers identified and reduce the high cost and high risk associated with thesetechnologies.

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Wave Energy Resource DistributionWave Energy Resource Distribution

2,000TWh/year of energy, the equivalent of 10% of the world electricity consumption, could be harvested from the world’s oceans (CRES, 2006)2,000TWh/year of energy, the equivalent of 10% of the world electricity consumption, could be harvested from the world’s oceans (CRES, 2006)

Resources

Estimate of Wave Energy ResourceEstimate of Wave Energy Resource

• Wave Energy Density

Average wave energy per unit area it has unit (work/per unit area)

•Wave Energy Flux through unit length at ocean surface

•Wave Energy Resource (Energy Flux * Time per unit length) Time of the wave at this height (per year) and per length of

the wave field normal the wave direction, kw*hr/m/year

2 21 1

2 8E gA gH

2 2 2N-m/m (J/m ),or lb-ft/ft

(Jole/s/m, W/m)

Wave Group Velocity

g

g

F EC

C

Example of Estimating Wave Energy ResourceExample of Estimating Wave Energy Resource

1 1

2 2

3 3

4

Near a coast area, the year-long wave characteristics are described below

Jan - Mar H = 5 m, T = 10s

Apr - Jun H = 4 m, T = 8s

July - Sept H = 3 m, T = 6s

Oct - Dec H = 6 4

2 21 1

1

1 1

m, T = 12s

What is Wave energy resource per unit length at this area?

1Jan - Mar H 31.56 /

8Assuming deep water C 7.81 /

Energy Flux per unit length = *C 246.5 /

In three m

g

g

E g kN m m

m s

E kw m

5

onths (, the total energy flux per unit length

246.5 / *90 (days)*24 (hr) 5.324*10 /kw m kwhr m

Example of Estimating Wave Energy ResourceExample of Estimating Wave Energy Resource

1 1

2 2

3 3

4

Near a coast area, the year-long wave characteristics are described below

Jan - Mar H = 5 m, T = 10s

Apr - Jun H = 4 m, T = 8s

July - Sept H = 3 m, T = 6s

Oct - Dec H = 6 4

22 2

2 2

m, T = 12s

What is Wave energy resource per unit length at this area?

Apr-Jun 20.2 / , in deep water C 6.25 /

Energy Flux per unit length = *C 126.3 /

126.3 / *91 (da

g

g

E kN m m m s

E kw m

kw m

5

23 3

3 3

5

ys)*24 (hr) 2.757*10 /

July-Sept 11.36 / , in deep water C 4.68 /

Energy Flux per unit length = *C 53.21 /

53.21 / *92 (days)*24 (hr) 1.175*10 /

g

g

kwhr m

E kN m m m s

E kw m

kw m kwhr m

Example of Estimating Wave Energy ResourceExample of Estimating Wave Energy Resource

24 4

4 4

5

Oct-Dec 45.45 / , in deep water C 9.37 /

Energy Flux per unit length = *C 425.8 /

425.8 / *92 (days)*24 (hr) 9.402*10 /

Hence, each year, Energy Flux per unit len

g

g

E kN m m m s

E kw m

kw m kwhr m

5

5 5 5 6

6

gth = 5.324*10

2.757*10 1.175*10 9.402*10 1.866*10 / per year

Average Energy Flux over unit length

1.866*10 / / (365*24 ) 213.0 /

If the wave field is 10 km wide, then the wave energy a

kwhr m

kwhr m hr kw m

10

t this area

per year is equal to 1.866*10 per year.kwhr

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Storage (and Transport) of Renewable EnergyStorage (and Transport) of Renewable Energy

Because renewable energy such as wind, wave and current energy, in general is not steady, the issue of storage of their energy become an important issue. The benefits of storage are significant, especially in integrating distributed power generation. Storage protects against mistakes in forecasting, removes barriers in connecting renewable sources to a variety of grids, shifts demand peaks by storing off-peak energy to sell back to the grid during peak times, provides frequency regulation and deters expensive grid upgrades.

Storage of Renewable EnergyStorage of Renewable Energy

The followings are a few ideas1.Large Battery System (High Performance Hydroxyl Conductive Membrane For Advanced Rechargeable Alkaline Batteries, High Energy, Low Temperature Rechargeable Battery for Load Leveling Application, & Nanostructured Cathode for Magnesium Ion batteries)  

2.Compress Air (For example, pumping pressured air into a massive case for storage) http://www.physorg.com/news188048601.html http://www.youtube.com/watch?v=dGd7PIC09AM3. Grid-scale Storage Project (pumping hydropower http://www.youtube.com/watch?v=iFdVX0NIPDE )

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Storage of Renewable EnergyStorage of Renewable Energy

4. Superconducting Magnetic Energy Storage http://www.youtube.com/watch?v=QU05d43dw6g

5. Combination the renewable energy device with other large energy consumption device (not only for storage but also saving transport cost)

1. Fuel Cell (use spare energy to produce Hydrogen & Oxygen from water)2.Desalination of sea water using renewable energy http://www.youtube.com/watch?v=bIrXKyWF8Nw3. Storage thermal energy (ice water, hot water and melting salts)4. Liquefy natural gas or industries consuming heavy power

19

The successful commercial deployment of all kinds of RE (renewable energy) devices depends on the cost.

The following is an example of the cost of a fixed offshore wind turbine.

The figure shows the breakdown of total system cost

Economic Assessment of RE Devices

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Items in the total cost

1)Support Structure (24%)2)Wind Turbine (33%)3)Grid Connection (Cable) (15%)4)O&M (operation and Maintenance) (23%)5)Others (5%)

Economic Assessment of RE Devices

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Storage Examples

http://www.youtube.com/watch?v=RlfDXAuhjwU

http://www.youtube.com/watch?v=JgmbPf1Jd-8

http://www.youtube.com/watch?v=hCywnjG9tes&feature=related

http://www.youtube.com/watch?v=Ra5WTItC0_4