To meet its renewable energy goals, the U.S. Navy plans to sign deals within the next few years for 1 gigawatt's worth of renewable energy projects, a service official said today, outlining a timeline that hinges on President Obama's reelection.

To allow adequate time for environmental reviews and construction, projects will need to be awarded by 2014 or 2015, William Tayler, the Navy's director for offshore energy, said today during a conference in Washington, D.C.

Navy Secretary Ray Mabus outlined his goal of getting 50 percent of the service's electricity from renewable sources by 2020 in October 2009. That target far exceeds legal mandates set by Congress. In recent weeks, the political leadership of the Air Force and the Army have set their own 1 GW goals, even as some GOP lawmakers have criticized the military's green energy efforts (Greenwire, April 11).

In addition to being the largest energy consumer in the federal government, the military is especially attractive to the renewable energy industry for its unique legal authority to sign power-purchase agreements that last up to 30 years. Other agencies are limited to 10-year agreements.

So far, the military has been concentrating on solar energy projects in the southwestern United States, where sunshine is plentiful and state incentives make renewable energy more economically competitive (Greenwire, Jan. 16).

But with most of its bases along the shoreline and several positioned on islands where the price of electricity is elevated, the Navy is especially interested in ocean energy technologies. In an interview with Greenwire, Tayler said the interest is a matter of both price and security.

Many island bases rely on overseas fuel shipments, which can be vulnerable to interruption, Tayler said. He pointed to Diego Garcia in the Indian Ocean as an example. The base there is a strategic launching pad into Asia, Africa and the Middle East, but the region is prone to political instability and natural disasters.

Tayler said his office plans to ink deals for solar energy projects in the near term, then turn its focus to emerging technologies like those that harness power from the sea. The service has previously invested in tests of ocean thermal energy technologies, which produce power based on the difference in temperature between surface water and deep water. Now, though, Tayler said the service is focusing on wave power.

Speaking today to an audience of ocean power developers, Tayler said the main challenge will be for ocean energy systems to increase their energy density.

"You've got to get the power density up so I don't have huge areas of the water with things bobbing around in there where I can't send a ship in," he told industry representatives. "You've got to get your density up so we can get fewer units out there and possibly locate them next to offshore wind farms and piggyback on the transmission line coming into shore."