MA'ALAEA, Maui — Just weeks after 20 giant turbines began spinning on the slopes of the West Maui Mountains above McGregor Point, Maui's first wind farm is producing its full 30 megawatts of power, or enough for 11,000 households.

The Kaheawa wind-energy project is expected to produce 9 percent of Maui Electric Co. needs, eliminating the need for 244,000 barrels of imported oil annually.

It is the first of two large-scale wind farms to be developed on Maui. MECO will get an additional 40 megawatts from a Shell Oil Co. project proposed for a remote corner of 'Ulupalakua Ranch on Haleakala. The $200 million Auwahi wind farm is expected to provide enough power for 15,000 homes.

At full capacity, both wind farms will provide more than 20 percent of MECO's electricity. The utility already is receiving 6 percent of its power from bagasse burning by the Hawaiian Commercial & Sugar Co. mill in Pu'unene.

The $70 million Kaheawa project is jointly owned by Maui-based Makani Nui Associates, whose partners are Kent Smith and Hilton Unemori, and Boston-based UPC Wind.

The renewable-energy firm sells electricity to MECO at half what it would cost the utility to produce the same amount of electricity using imported oil, but consumers are not likely to see a difference in their power bills anytime soon, according to MECO President Ed Reinhardt.

The utility is still figuring out what impact the new energy producer will have on its power-generating operations, Reinhardt said.

"So far it has met its projected output, but we're still working through some of the bugs," he said.

Reinhardt also noted that when there's no wind, the turbines won't be contributing any electricity to the power grid. Kaheawa officials are confident that will be a rare occurrence, since winds at the site consistently blow an average of 24 mph.

Mike Gresham, president of Makani Nui, said at first glance the project looked like a risky proposition because it was proposed for a steep ridge running from the 2,000- to 3,200-foot elevation with no access except by a rough trail, the parts and equipment had to be shipped in from around the globe, and there was no crane large enough on the island to erect the 180-foot-tall towers and 117-foot-long rotors.

Construction of a four-mile dirt and gravel road on a mountainside with an average 15-degree grade proved the most daunting challenge of the project, costing $6 million and resulting in $11,100 in state penalties when the road was cut wider than allowed and excavated dirt and boulders ended up in a gulch.

State and federal approval also was needed since the project sits on state conservation land and there was a risk to four protected species known to frequent the area.

Officials said the Kaheawa wind farm is the first in the country to be built with a state and federally approved habitat conversation plan. The 20-year plan established actions to minimize the potential for collisions with wildlife during construction and operation of the facility, in particular the Hawaiian hoary bat, or 'ope'ape'a; the Hawaiian goose, or nene; the Hawaiian petrel, or 'ua'u; and the Newell's shearwater, or 'a'o.

The company has hired a full-time wildlife biologist and will provide at least $384,000 for conservation efforts.

Kaheawa began phasing in its wind turbines in early June, and by the end of the month it had produced 6 million kilowatt-hours of power and saved MECO 10,000 barrels of oil.

A formal commissioning ceremony was held Friday.

Reach Christie Wilson at cwilson@honoluluadvertiser.com.