Economies of Scale Could Swell Ocean Energy

The study was carried out by Electric Power Research Institute (EPRI), in collaboration with the DOE's National Renewable Energy Laboratory (NREL) and energy agencies and utilities from six states. EPRI was established in 1973 as an independent, non-profit center for public interest energy and environmental research. Their members represent over 90 percent of the electricity generated in the United States.

Conceptual designs for 300,000 MWh plants (nominally 120 MW plants operating at 40 percent capacity factor) were performed for five sites: Waimanalo Beach, Oahu, Hawaii; Old Orchard Beach, Cumberland County, Maine; WellFleet, Cape Cod, Massachusetts; Gardiner, Douglas County, Oregon; and Ocean Beach, San Francisco County, California.

The study determined that wave energy conversion may be economically feasible within the territorial waters of the United States as soon as investments are made to enable wave technology to reach a cumulative production volume of 10,000 - 20,000 MW. (Land-based wind turbines, in comparison, generate 40,000 MW.)

"Wave energy will first become commercially competitive with land-based wind technology at a cumulative production volume of 10,000 or fewer MW in Hawaii and northern California, about 20,000 MW in Oregon and about 40,000 MW in Massachusetts," said Roger Bedard, ocean energy project manager. "Maine is the only state in the five site study whose wave climate is such that wave energy may never be able to economically compete with a good wind energy site."

This forecast was based on the output of a 90 MW Pelamis wave energy conversion plant design and application of technology learning curves that will enable cost savings. The forecast results have convinced the project team of the rationale for investment in wave energy technology research and development, including demonstration projects to prove the feasibility of wave energy conversion technology in actual sea-state environments.

Bedard explained that there are several compelling arguments for investing in offshore wave energy technology. First, with proper siting conversion of ocean wave energy to electricity is believed to be one of the most environmentally benign ways to generate electricity.

Second, offshore wave energy offers a way to minimize the 'Not in my backyard' (NIMBY) issues that plague many energy infrastructure projects. Wave energy conversion devices often have a very low profile and are located far enough away from the shore that they are generally not visible.

Third, wave energy is more predictable and consistent than solar and wind energy, offering a better possibility of being dispatchable by an electrical grid systems operator and possibly earning a capacity payment.

A characteristic of wave energy that suggests that it may be one of the lowest cost renewable energy sources is its high power density. Processes in the ocean concentrate solar and wind energy into ocean waves, making it easier and cheaper to harvest, according to the research team. Solar and wind energy sources are much more diffuse, by comparison.

Wave power was delivered to the electrical grid for first time in August 2004. The electricity was generated by a full-scale, pre-production Pelamis prototype in Orkney, Scotland by Ocean Power Delivery Corporation.

"Wave energy is an emerging energy source that may add a viable generation option to the strategic portfolio," said Hank Courtright, EPRI's VP, Generation. "The bedrock of a robust electricity system is a diversity of energy sources, and wave energy could provide an energy source that is consistent with our national needs and goals."

The offshore wave energy reports can be accessed at the following link.