Hawaiian Electric Co. is reviewing nine proposals for renewable energy projects that would provide 100 megawatts or more of electricity for O'ahu.

HECO, which in June issued a call for such proposals from developers, said it's received plans for biomass power generation, ocean power, solar power and wind power projects and is checking them for completeness before starting an evaluation process.

"We are pleased with both the number and variety of bids from renewable energy developers eager to bring more than 100 megawatts of clean, alternative electricity for O'ahu," said Hawaiian Electric spokesman Peter Rosegg.

"Our goal is to move as quickly as responsibly possible to add a diverse selection or portfolio of renewable electric sources on the grid of this island."

Under the Hawaii Renewable Portfolio Standards law, HECO and its subsidiaries are required to generate or purchase electricity from renewable resources. That includes having renewables provide 10 percent of net electricity sales by 2010 and 15 percent by 2015. By 2020, the utility is to get 20 percent from renewables.

The projects have become more important as the price of oil has surged, taking Hawai'i's nation-leading electricity prices along with it. Most of the state's electricity — an estimated 85 percent — is generated from petroleum, contributing to the state's dependence on oil.

"Every new renewable energy project is a good opportunity to reduce our dependence on oil," said Rick Rocheleau, director of the Hawaii Natural Energy Institute at the University of Hawai'i.

"A hundred megawatts is a significant amount of power."

The 100 megawatts would be a significant step forward in renewable generation for O'ahu and the state. It is being requested at a time when HECO is progressing toward installation and operation of its own 110-megawatt biofuel-fired generation unit.

Currently, the 46-megawatt HPower garbage-to-energy plant at Campbell Industrial Park is O'ahu's only major renewable energy producer, but projects already under consideration include a 30-megawatt windfarm on the North Shore, a 6.2-megawatt steam turbine generator at Campbell Industrial Park and an up-to-100-megawatt ocean thermal energy conversion facility at Kahe Point.

Rosegg declined to release the scope of the latest proposals or their developers. Among the developers is thought to be Castle & Cooke Inc., which last month was said to be interested in submitting a plan. Castle & Cooke has talked about building the state's largest windfarm on Lana'i and transmitting the power to O'ahu by undersea cable.

Hawaiian Electric has not set a deadline for completing the evaluations, but has targeted getting the power starting in the 2010 to 2014 timeframe. It could choose multiple projects and might go over or below the 100 megawatts it is seeking.