Ocean Power: Major promise for the future


Wave Energy

The moving waves of the ocean can be used to power a turbine. There are many types of wave-energy systems. Some use the up and down motion of the wave to power a piston that moves up and down inside a cylinder. Others .... The total power of waves breaking on the world's coastlines is estimated at 2 to 3 million megawatts. In favorable locations, wave energy density can average 65 megawatts per mile of coastline.

Tidal Energy

Tidal energy traditionally involves erecting a dam across the opening to a tidal basin. The dam includes a sluice that is opened to allow the tide to flow into the basin; the sluice is then closed, and as the sea level drops, traditional hydropower technologies can be used to generate electricity from the elevated water in the basin.

La Rance Station in France makes enough energy from tides (240 megawatts) to power 240,000 homes. It began making electricity in 1966. It produces about one fifth of a regular nuclear or coal-fired power plant. It is more than 10 times the power of the next largest tidal station in the world, the 17 megawatt Canadian Annapolis station.

Ocean Thermal Energy Conversion (OTEC) Systems

A great amount of thermal energy (heat) is stored in the world's oceans. Each day, the oceans absorb enough heat from the sun to equal the thermal energy contained in 250 billion barrels of oil. OTEC systems convert this thermal energy into electricity by using the difference in temperature to make energy. A difference of at least 38 degrees Fahrenheit is needed between the warmer surface water and the colder deep ocean water. urce is called Ocean Thermal Energy Conversion or OTEC. It is being demonstrated in Hawaii.

More info on OTEC can be found on the archive pages for the Natural Energy Laboratory of Hawaii at: www.hawaii.gov/dbedt/ert/otec-nelha/otec.html

This is an excerpt from a report by the Electric Power Research Institute (USA) titled A Compelling Case for Investing in Wave Energy RD&D, published 14 January 2005.

'In addition to economics there are other compelling arguments for investing in offshore wave energy technology. First, with proper siting, converting 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 minimise the 'Not In My Backyard' issues that plague many energy infrastructure projects, from nuclear to coal and to wind generation. Because these devices have a low profile and are located at a distance from the shore, they are generally not visible. Third, because wave energy is more predictable than solar and wind energy, it offers a better possibility than either solar or wind of being dispatchable and earning a capacity payment.

A characteristic of wave energy that suggests it may be one the lowest cost renewable energy source is its high power density. Processes in the ocean concentrate solar and wind energy into ocean waves, making it easier and cheaper to harvest. Solar and wind energy sources are much more diffuse, by comparison. Lastly, since a diversity of energy sources is the bedrock of a robust electricity system, to overlook wave energy is inconsistent with national needs and goals. Wave energy is an energy sources that is too important to overlook.'

Ocean information reproduced from US Department of Energy http://www.eere.energy.gov/RE/ocean.html

FERC to Streamline Ocean Energy Permitting Process for Pilot Projects

Vancouver, Canada, July 23rd, 2007 - The United States Federal Energy Regulatory Commission (FERC) announced a proposal to shorten the permitting process for pilot ocean energy projects to as little as six months.  As part of its proposal, FERC will convene a public hearing on licensing pilot projects in Portland, Oregon on Oct. 2, 2007.

The proposal made by FERC is for projects five megawatts or less, removable or able to shut down on relatively short notice, located in waters that have no sensitive designations, and for the purpose of testing new hydro technologies or determining appropriate sites for ocean, wave and tidal energy projects.

To date, the regulatory process has been one of the primary hurdles to the commercialization of offshore wave energy.  Trial projects have taken years to move through the permitting process, taking away valuable time in enacting a technology that shows great promise in reducing dependence on fossil fuels.