Hawaii Electric Light Co. announced Thursday it is ready to receive offers for expanding geothermal power on the Big Island by up to 50 megawatts.
Bids are due April 30 and the power utility expects to make a decision 120 days afterward.
Expanding geothermal power, though controversial, has been seen as a way for the island to produce more low-cost, renewable energy while reducing its dependency on oil.
HELCO President Jay Ignacio said the Thursday release of its request for proposals, part of the bidding process, marks an exciting time for the utility.
“We believe that the pricing for the energy from geothermal can be lower cost,” he said.
Ignacio said it can also help secure reliable service and offset oil-power production.
Geothermal energy is produced by pumping water deep into the earth, where it comes into contact with volcanically heated rock and becomes steam.
The steam is pumped through the plant to produce electricity before being reinjected into the ground.
HELCO has a contract with Puna Geothermal Venture, the state’s only geothermal power plant, for 38 megawatts of electricity. That accounts for about 20 percent of the island’s energy needs.
The company solicited comments for expanding geothermal development on the island in June 2011. Twenty companies responded.
Ignacio said it’s unclear how many will submit bids.
HELCO is requiring bidders to have secured a site for a power plant.
At least two potential bidders have looked at property in Puna, the island’s most volcanically active area.
It’s been about 20 years since PGV, located off Kapoho Road, was built. But geothermal critics in the district remain vocal and are promising a fight if selected for another plant.
“There’s probably going to be a big fight over this,” said Bob Petricci, a geothermal critic, adding that litigation and civil disobedience actions are both possible.
Opponents say they are concerned about release of hydrogen sulfide and other gases. Other concerns include industrializing the rural area through the construction of more power plants.
PGV says its plant operates on a closed system.
Releases have been known to occur but the state Department of Health has found the facility to not be a public health concern. Geothermal critics believe air quality testing has been inadequate.
The slopes of Hualalai in Kona have also been noted as a potential geothermal site.
State Sen. Russell Ruderman, D-Puna, another geothermal critic, said it would make more sense to locate a plant on that side of the island, due to both opposition in Puna and shorter transmission distances.
“If they choose Puna they are going to have the biggest fight we are going to see on their hands,” he said.
“We are hypersensitive and very, very knowledgeable and organized about it.”
Ignacio said bidders are required to address environmental, cultural and health concerns.
“We are going to review that as part of the evaluation process,” he said.
HELCO says new contracts will not be tied to the price of oil, allowing for lower prices.
Twenty-five of the 38 megawatts of power HELCO buys from PGV is tied to oil, the result of a federal law regarding renewable energy development from the 1970s.