Wave power goes online in Hawaii
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 kilometre 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 the U.S.’s energy needs and dramatically reduce reliance on oil, gas and coal. But wave energy technology lags behind wind and solar power, with important technical hurdles still to be overcome.
To that end, the U.S. navy has established a test site in Hawaii, with hopes the technology can someday be used to produce clean, renewable power for offshore fuelling stations for the fleet and provide electricity to coastal communities in fuelstarved 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 during an event at the site. “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 highest electricity costs in the U.S. — largely because of its heavy reliance on oil delivered by sea — and has a legislative mandate to get all 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 say.
“You’ve got to design something that can stay in the water for a long time but be able to survive,” said Patrick Cross, specialist at the Hawaii Natural Energy Institute at the University of Hawaii at Manoa, which helps run the test site.
Wave-energy technology is at about 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.
But while the U.S. government and military have put about $334 million US into marine energy research over the past decade, Britain and the rest of Europe have invested more than $1 billion, according to the Marine Energy Council, a trade group.
The European Marine Energy Centre in Scotland, for example, has 14 grid-connected berths that have housed dozens of wave and tidal energy devices from around the world over the past 13 years, and Wave Hub in England has several such berths. China, too, has been building and testing dozens of units at sea.
Though small in scale, the test project near Kaneohe Bay represents the vanguard of U.S. wave energy development. It consists of two buoys anchored a kilometre offshore.
One of them, the Azura, which extends four metres above the surface and 17 metres below, converts the waves’ vertical and horizontal movements into up to 18 kilowatts of electricity, enough for a dozen homes. The firm working with the navy, Northwest Energy Innovations of Portland, Oregon, plans a version that can generate at least 500 kilowatts, or enough to power hundreds of homes.