U.S. Department of Energy - Energy Efficiency and Renewable Energy

Water Power Program

Harnessing Tidal Power, While Protecting Marine Life

August 3, 2011

Below the surface of U.S. coastal waters could be the energy needed to power your clothes dryer and other appliances. Some say tides have the potential to power about 5% of U.S. households by producing nearly nine gigawatts of renewable energy.

A pilot project to test this potential is in the works in Washington state's Puget Sound. The Snohomish County Public Utility District was awarded a $10 million grant from DOE to install two tidal energy turbines on the floor of Admiralty Inlet, a trough of fast-moving water about 35 miles northwest of Seattle. Much like how wind turbines convert wind energy, the project's underwater turbines will generate electricity from ebbing and flowing tidal waters. At peak tidal currents, the two turbines could generate more than one megawatt of electricity, enough to power about 700 American homes. See the Energy Blog post.