The U.S. Department of Energy has committed to guaranteeing a $117 million loan for a wind farm that hopes to break ground this year in the hills across from the shrimp farms near Kahuku.

At 30 megawatts, the project would be the largest wind energy endeavor undertaken on O'ahu and would include an innovative battery system to help with electricity load stability.

"It's just great news for the people of Hawai'i," said Ted Peck, state energy administrator.

"It's one more step toward loosening the shackles of fossil fuel."

The project by Kahuku Wind Power LLC comes as the state pursues a goal of getting 40 percent of its electricity from renewable sources by 2030. Kahuku's steady winds have become the focal point of developers looking to put in wind farms, just as the area was a test site for wind turbines in the 1980s.

Peck said the project by Kahuku Wind Power has the distinction of being the first wind farm project to earn one of the Energy Department's loan guarantees. The commitment will help Kahuku Wind, a unit of Newton, Mass.-based First Wind, gain financing for the project from lenders.

The loan guarantee is conditioned on the project obtaining regulatory permits and clearances, including clearing an environmental assessment that is now in the process of taking public comments.

"It makes it significantly easier to obtain financing," said John Lamontagne, First Wind spokesman.

Loan guarantees provide assurances that the government will pick up obligations for the debt should the borrower fail.

"We're hoping to start construction this year," Lamontagne said.

The project calls for installation of a dozen 2.5-megawatt Clipper Liberty turbines on about 575 acres, most of which is owned by First Wind. The three-blade turbines would sit on conical tubular steel towers 260 feet high, with turbine blades reaching a maximum of 460 feet at the zenith of their motion.

The site would also house facilities for the operation of the wind farm and a battery storage system that will hold about an hour of energy.

"It helps smooth out the periods when wind slows down," Lamontagne said.

First Wind estimates the project will have the capacity to generate enough energy to power 7,700 homes and eliminate use of about 155,000 barrels of oil annually. Much of Hawai'i's electric power comes from fuel- and diesel-fired generators and is one reason why almost 90 percent of the state's energy comes from imported petroleum.

The project would also reduce air pollution here. "This investment will create jobs and cut our dependence on oil, while promoting America's leadership in the global race for the clean energy industries of tomorrow," U.S. Energy Secretary Steven Chu said in a press statement announcing the loan guarantee.

The developer estimates that about 200 construction workers would be employed building the wind farm, with another six to 10 people employed for its operation.

Power generated by the more-than-$117-million facility will be sent into the grid owned by Hawaiian Electric Co., which last year signed an agreement to buy the wind farm's power. That accord is now being examined for approval by the state Public Utilities Commission.

HECO spokesman Peter Rosegg said the wind farm will be the biggest independent power project on O'ahu since HPower began operations in 1987.

He said more such projects are on the way, with HECO close to picking more renewable providers to generate 100 megawatts of electricity on O'ahu.

He said that group will include other wind farms, but could not release more details. At least one other has been proposed for Kahuku. That 25-megawatt project by West Wind Works LLC has drawn some criticism from some Kahuku residents who say it will be too noisy for nearby homes.

First Wind also operates the 30-megawatt Kaheawa wind farm on Maui, where it is proposing to install another 21 megawatts worth of turbines. It also is pursuing a 200-megawatt wind farm on Moloka'i that would provide power to O'ahu through an undersea cable that also has been proposed by the state.