Tidal power, also called tidal energy, is a form of hydropower that converts the energy of tides into electricity or other useful forms of power. The first large-scale tidal power plant (the Rance Tidal Power Station) started operation in 1966. Harnessing the power of ocean tides has long been imagined, but countries are only now putting it into practice. A demonstration project planned for Puget Sound will be the first tidal energy project on the west coast of the United States, and the first array of large-scale turbines to feed power from ocean tides into an electrical grid. University of Washington researchers are devising ways to site the tidal turbines and measure their environmental effects. Brian Polagye, UW research assistant professor of mechanical engineering, will present recent findings this week in an invited talk at the American Geophysical Union’s annual meeting in San Francisco.