The push to generate more of Hawaii’s energy from renewable sources is picking up speed this year with a host of new green projects moving their way through the pipeline.

The biggest single factor will be wind power, with the state poised to add more than 100 megawatts of generating capacity from projects on Oahu and Maui in 2012. Rapid growth of residential and commercial photovoltaic installations is continuing, while new waste-to-energy and biofuel projects are also on tap for completion this year.

In addition, the electric utilities that service Hawaii island and Maui are seeking proposals from developers to expand the state’s electricity production from geothermal sources.

Hawaii’s reliance on high-priced oil for electricity generation has made the development of alternative energy sources attractive here. The additional investment needed to upgrade the state’s electrical grid to incorporate more renewable electricity will increase costs for ratepayers in the near future. But alternative energy proponents say reducing dependence on imported oil will provide more stable, and lower, energy prices over time.

While much of Hawaii’s energy policy has been focused on developing renewable resources, officials also are looking at bringing in natural gas as a cheaper alternative to oil to satisfy some of the state’s energy needs.

Wind and solar power, however, remain the dominant near-term responses to Hawaii’s dependence on fossil fuel.

First Wind LLC’s 69-megawatt Ka­wai­loa wind energy project, scheduled to begin operation on Oahu’s North Shore later this year, will be the state’s largest such facility. Boston-based First Wind also will begin operating a 21-megawatt expansion of its Kahe­awa wind project this summer on a ridge in the West Maui mountains. And across the Valley Isle on the slopes of Hale­akala, work has begun on another 21-megawatt wind energy project which Sempra Generation hopes to have completed by December.

Both solar and wind projects present challenges for electric utilities because the energy they generate is intermittent, meaning the output can vary widely depending on uncontrollable events such as cloud cover and fluctuations in wind speed.

Developers also are pursuing several renewable energy projects in Hawaii that will deliver a steady flow, so-called firm power, to utilities. The biggest is a 30-megawatt expansion of the HPOWER garbage-to-energy power plant due to be completed this summer at Campbell Industrial Park in West Oahu. The expanded facility will burn more than 800,000 tons of garbage a year and supply 8 percent of Oahu’s electricity needs.

The electric utility on Hawaii island, which already absorbs the highest amount of renewable energy in the state, has agreed to add 21.5 megawatts of firm generating capacity from a company that will produce power by burning locally grown eucalyptus trees. The project being developed by Hu Honua Bioenergy will produce enough power to supply 10 percent of the island’s energy needs.

Hawaii island also is home to the state’s newest and largest biodiesel plant. Pacific Biodiesel, founded on Maui 15 years ago, recently held a grand opening for a plant on Hawaii island that can produce 5.5 million gallons of biodiesel a year from a variety of feedstocks, from restaurant oil waste to seed crops such as jatropha. The biodiesel can be burned in vehicles or machinery that run on petroleum-based diesel.

Kelly King, Pacific Biodiesel’s director of communications and marketing, said the company has been able to maintain steady growth by keeping focused on what businesses and individuals have demanded in the way of liquid biofuel. Many of the companies that pursued other petroleum alternatives in the past, such as ethanol, have disappeared, she said.

"A lot of people jumped on the bandwagon five or six years ago. People were investing almost blindly, jumping into the fray to make money," King said. "Now we’re getting back to what makes sense. We call it the triple bottom line: the environment, the economy and social benefits."

Hawaii island also lays claim to having the state’s only geothermal plant, a facility owned by Puna Geothermal Venture that produces 38 megawatts of firm power. Hawaii Electric Light Co. is preparing to seek bids from developers to supply another 50 megawatts of geothermal generating capacity on the island. Maui Electric Co. also is looking to add geothermal power to its energy portfolio.