Two reports assessing wave and tidal resources in the U.S. released today by the Department of Energy (DOE) suggest that water power—including conventional hydropower and wave, tidal, and other resources—could provide 15% of the nation’s electricity by 2030.

The two reports—"Mapping and Assessment of the United States Ocean Wave Energy Resource" and "Assessment of Energy Production Potential from Tidal Streams in the United States"—were described by the DOE as “the most rigorous analysis undertaken to date to accurately define the magnitude and location of America’s ocean energy resources.”

The U.S. uses about 4,000 TWh of electricity per year, about 6% of which is generated by hydropower resources. According to the reports, the DOE estimates that the maximum theoretical electric generation that could be produced from waves and tidal currents is about 1,420 TWh per year—or about a third of the nation’s total annual electricity usage.

The DOE notes cautiously, however, that “not all of the resource potential identified in these assessments can realistically be developed.”

The two reports calculate the maximum kinetic energy available from waves and tides off U.S. coasts that could be used for future energy production, and which represent largely untapped opportunities for renewable energy development in the U.S. The West Coast, including Alaska and Hawaii, have especially high potential for wave energy development, while significant opportunities for wave energy also exist along the East Coast. “Additionally, parts of both the West and East Coasts have strong tides that could be tapped to produce energy,” the DOE concludes.

Earlier this year, the DOE announced the availability of its national tidal resource database, which maps the maximum theoretically available energy in the nation’s tidal streams. This database contributed to the "Assessment of Energy Production Potential from Tidal Streams in the United States" report, prepared by Georgia Tech.

The wave energy assessment report, titled "Mapping and Assessment of the United States Ocean Wave Energy Resource," was prepared by the Electric Power Research Institute (EPRI), with support and data validation from researchers at Virginia Tech and the DOE’s National Renewable Energy Laboratory (NREL). The report describes the methods used to produce geospatial data and to map the average annual and monthly significant wave height, wave energy period, mean direction, and wave power density in the coastal United States. NREL incorporated the data into a new marine and hydrokinetic energy section in its U.S. Renewable Resource atlas.

The DOE said it now plans to release additional resource assessments for ocean current, ocean thermal gradients, and new hydropower resources in 2012.

Sources: POWERnews, DOE