State and federal officials are holding public meetings starting tomorrow on an environmental study of the proposed transmission of wind energy from Maui County to Oahu by undersea cable. The project could cost $1 billion, officials estimate.

But the environmental group Life of the Land said government officials should be looking instead at generating electricity through ocean thermal energy conversion.

"OTEC would cost less," said Henry Curtis, executive director of Life of the Land.

The study, funded with up to $2.9 million in federal stimulus money, is intended to help the state meet its 2030 goal of providing 40 percent of its net electricity sales through locally generated renewable energy.

The plan is to have wind energy provide up to 400 megawatts of electricity via undersea cable.

State official Allen Kam said wind energy transmitted by undersea cable is one of a variety of options using alternative energy technologies to meet the state’s renewable-energy goal.

He said preliminary studies show Maui County has "world-class winds."

"The wind is strong, steady … and pretty much always on," said Kam, a manager with the Hawaii Interisland Renewable Energy Program, part of the state Department of Business, Economic Development and Tourism.

Curtis, however, said that in terms of reliability, OTEC tops wind and solar.

OTEC uses the temperature differential between cold, deep seawater with warm surface water to generate power through the transfer of heat. In the 1980s and 1990s, an experimental plant at Keahole Point on the Big Island accessed deep water just offshore through a pipe, but the project was dropped because it was too costly compared to cheap oil.

Kam said he’s unaware of any commercial-scale OTEC projects today.

Josh Strickler, the state’s facilitator of renewable- energy programs, said the state continues to support OTEC research on the Big Island but the technology is still in the testing stages.

"I would love to see OTEC come on line, but it’s just not there right now," he said.

Kam said a developer of an undersea cable project would still have to prepare a separate environmental impact statement and give the public the opportunity to comment on the project.

What is currently under review is a state and federal "programmatic" EIS, which would provide information that could be useful to a prospective undersea cable developer and help to quicken the development of a separate environmental study, Kam said.

The potential entry sites for the cable include northeast and south-central Molokai, northeast Lanai and Kahului Harbor on Maui.

The landing site of the cable on Oahu could be located on the east side of the Mokapu Peninsula at the Marine Corps Base and the leeward side between Pearl Harbor and Honolulu Harbor.

Kam said Castle & Cooke wants to develop a large wind farm on Lanai, and First Wind is interested in developing a wind farm on Molokai that could transmit energy through undersea cable.

The state said some 20 undersea electrical transmission cables are in operation around the world, including a Tasmania-Australia link, the Cross-Sound Cable between Long Island and New York, and the Trans Bay Cable in San Francisco.