What is ocean energy?

Ocean energy refers to a range of technologies that utilize the oceans to generate electricity. Many ocean technologies are also adaptable to non-impoundment uses in other water bodies such as lakes or rivers. These technologies can be separated into three main categories:

Wave Energy Converters: These systems extract the power of ocean waves and convert it into electricity. Typically, these systems use either a water column or some type of surface or just-below-surface buoy to capture the wave power. In addition to oceans, some lakes may offer sufficient wave activity to support wave energy converter technology.

Tidal/Current: These systems capture the energy of ocean currents below the wave surface and convert them into electricity. Typically, these systems rely on underwater turbines, either horizontal or vertical, which rotate in either the ocean current or changing tide (either one way or bi-directionally), almost like an underwater windmill. These technologies can be sized or adapted for ocean or for use in lakes or non-impounded river sites.

Ocean Thermal Energy Technology (OTEC) OTEC generates electricity through the temperature differential in warmer surface water and colder deep water. Of ocean technologies, OTEC has the most limited applicability in the United States because it requires a 40 degree temperature differential that is typically available in locations like Hawaii and other more tropical climates.

Is ocean energy commercially viable now?

Yes, but thus far, on a small scale and not in the United States:

? The LIMPET project, a 500 kw shore-based wave plant in Scotland has been feeding power to the grid for 5 years at a cost of 7 cents a kilowatt/hr. Another 600 kw project similar to LIMPET on Island of Pico in the Azores is operational.

? The Pelamis, a Scottish wave energy converter has been feeding power to the grid in Scotland since August 2004 – and recently announced plans to construct a 2.25 MW plant off the coast of Portugal.

? An Australian company, Energetech, has deployed a 500 kw wave energy device in Port Kembla, Australia which will feed power into the Australian grid.

What is the status of US wave, current and tidal projects?

A number of such projects in the United States have been proposed and are on the cusp of deployment:

? New Jersey based Ocean Power Technologies has operated a test wave energy buoy off the coast of Hawaii for the U.S. Navy and plans to interconnect to the grid by the end of the year.

?  Washington state based Aqua Energy has proposed a 1 MW pilot project for the Makah Bay off the coast of Washington state. The project is currently in the midst of what is now verging on a three year permitting process at the Federal Energy Regulatory Commission. (FERC)

? New York based Verdant Power is undergoing licensing at FERC and intends to deploy six units of a tidal/current project located in the East River and supply power to customers on Roosevelt Island imminently, once all regulatory clearances have been obtained.

? Australian based Energetech has formed a subsidiary in Rhode Island which has received funding from the Massachusetts Trust Collaborative and has planned a 750 kw project for Port Judith Rhode Island. Permitting has not yet commenced.

Are these projects discussed above the start of real commercialization?

Yes – or at least that’s what the Electric Power Research Institute (EPRI), perhaps the nation’s most prominent utility research collaborative, concluded. An EPRI Report released in January 2005 found that “wave energy is an emerging energy source that may add a viable generation option to the strategic portfolio.” Among the benefits of wave that the report identified are that it is environmentally benign, has a low profile and is generally not visible and is more predictable than solar and wind so it is more dispatchable to the grid. In light of the success of its wave energy report, EPRI has now embarked on a second stage of exploring the energy potential of tidal and current ocean and coastal resources.

The EPRI report found that presently, the cost of power from ocean technologies ranges from 7 cents to 16 cents/kw in a low case scenario. But these costs are expected to decline as the industry matures and as economies of scale make ocean projects less costly. To compare, back in 1978 wind energy cost 25 cents/kwh to produce – but now costs between 4.5 and 6 cents/kwh. Wave is already less costly than wind. Moreover, the EPRI report found that if wave had obtained the same government subsidies as wind, it would be a far more advanced technology than at present.

Can ocean energy technologies be used in fresh water like lakes or rivers?

Yes, and the potential for using non-impounded hydrokinetic resources is tremendous. I emphasize the terms non-impounded and hydrokinetic for two reasons.  The first is that non-impounded resources means that you don’t have to dam a river to capture the power from free flowing water.  Secondly, when using hydrokinetic devices to capture energy, understanding the physics and the environment is important.  The U.S. wind power industry learned that when their wind turbines moved fast they would kill birds.  By slowing the blades down using the equivalent of gear systems they found they could extract the energy from the wind, and not have the impact on birds.  There were also advances in the design of the poles that hold the wind turbines that helped protect the environment.

Moreover, fresh water power resources are abundant. A 2004 U.S. Dept. of Energy Study showed that states like Idaho, Missouri, Ohio, and many others are high on the list of having substantial available free flowing freshwater hydro resources.

Nearly Half of Americans Unaware of Power From the Sea

Cambridge,Massachusetts—A recent survey conducted by Opinion Dynamics Corporation shows that nearly half of Americans are not aware of the vast potential of generating electricity from the motion of waves, tides, and currents.  However, when asked if the federal government should be funding ocean energy projects, seventy percent (70%) of the 900 registered voters contacted by telephone voiced their support.  When asked to factor in  ocean energy’s potential help in reducing America’s dependency on foreign sources of energy, eighty-one percent (81%) said that they would be more likely to support increased funding.

“There is a surprising amount of support for federal funding,” stated Sean O’Neill, Executive Director of the Foundation for Ocean Renewables (www.foroceanenergy.org). “At the same time, it shows we have a lot to do to get the word out that ocean renewables will help us on our path to energy independence,” he added. The survey was conducted March 14 and 15, 2006 and included a random sample of 900 registered voters, nationwide. 

1.         When I mention the words, “ocean energy”, what comes to mind?

(Wave power, electric power from waves) 19%
(Renewable energy) 12
(Tidal power, electric power from tides) 9
Oil rigs & drilling/Gas 8
Ocean power/Energy from the sea 3
Hydro power/Hydro electricity 2
Tsunami(s)/Hurricanes 1
Alternative energy 1
Wind mills/Wind power 1
Global warming
Salt to fresh water conversion
Spills/Pollution
Conservation/Environment
(Other) 3
(Don’t know) 42
(Refused) 1

2.         In fact, “ocean energy” is a term used for a renewable means of electricity generation achieved by capturing the energy contained in moving water due to tides, waves, currents, and even ocean temperatures. In general, do you think the federal government should invest more public money in the further development of “ocean energy”, or not?

Yes, federal government SHOULD invest more 70%
No, federal government SHOULD NOT invest more 16
(Combination, depends) 6
(Don’t know) 8

3.         If you knew that further development of “ocean energy” could help reduce America’s dependence on foreign sources of energy, would you be much more likely to support increased funding of “ocean energy” by the federal government, somewhat more likely, or wouldn’t it make any difference to you?

Much more likely 55%
Somewhat more likely 26
No difference 14
(Don’t know) 5