KANEOHE BAY, Hawaii — Off the coast of Hawaii, a tall buoy bobs and sways in the water, using the rise and fall of the waves to generate electricity.
The current travels through an undersea cable for a mile to a military base, where it feeds into Oahu’s power grid — the first wave-produced electricity to go online in the U.S.
By some estimates, the ocean’s endless motion packs enough power to meet a quarter of America’s energy needs and dramatically reduce the nation’s reliance on oil, gas and coal. But wave energy technology lags well behind wind and solar power, with important technical hurdles still to be overcome.
To that end, the Navy has established a test site in Hawaii, with hopes the technology can someday be used to produce clean, renewable power for offshore fueling stations for the fleet and provide electricity to coastal communities in fuel-starved places around the world.
“More power from more places translates to a more agile, more flexible, more capable force,” Joseph Bryan, deputy assistant secretary of the Navy, said. “So we’re always looking for new ways to power the mission.”
Hawaii would seem a natural site for such technology. As any surfer can tell you, it is blessed with powerful waves. The island state also has the nation’s highest electricity costs and has a legislative mandate to get 100 percent of its energy from renewables by 2045.
Still, it could be five to 10 years before wave energy technology can provide an affordable alternative to fossil fuels, experts said.
Developers are still working to come up with the best design. Some buoys capture the up-and-down motion of the waves, while others exploit the side-to-side movement. Industry experts said a machine that uses all the ocean’s movements is most likely to succeed.
Also, the machinery has to be able to withstand powerful storms, the constant pounding of the seas and the corrosive effects of saltwater.
Jose Zayas, a director of the Wind and Water Power Technologies Office at the U.S. Energy Department, which helps fund the Hawaii site, said the U.S. could get 20 to 28 percent of its energy needs from waves without encroaching on sensitive waters such as preserves.
“When you think about all of the states that have water along their coasts … there’s quite a bit of wave energy potential,” he said.
Wave energy technology is at the same stage as the solar and wind industries were in the 1980s. Both received substantial government investment and tax credits that helped them become energy sources cheap enough to compete with fossil fuels.
The test project near Kaneohe Bay represents the vanguard of U.S. wave energy development. It consists of two buoys anchored a half-mile to a mile offshore.
One of them, the Azura, which extends 12 feet above the surface and 50 feet below, converts the waves’ movements into up to 18 kilowatts of electricity, enough for about a dozen homes. Northwest Energy Innovations of Portland plans a version that can generate 500 kilowatts, or enough to power hundreds of homes.
