Hawaii Electric Light Co.’s recently launched search for developers to expand geothermal energy production on Hawaii island emphasizes the potential benefits of locating new production facilities on the west side of the island where population growth is the fastest.
However, the island’s lone geothermal plant is in the isolated Puna District in the southeastern part of the island, and power is lost when electricity is transmitted long distances. Losses associated with sending electricity from the plant more than 100 miles to some areas in West Hawaii ultimately adds to the cost of power for ratepayers.
The Puna Geothermal Venture plant on the east rift zone of Kilauea volcano has the only proven commercially viable geothermal resource in the state. However, in its draft request for proposals, or RFP, HELCO identifies four other areas with geothermal potential, including a spot on the slopes of Hualalai overlooking Kailua-Kona.
"Assuming new geothermal generation is added by one or more selected bidders in the Kilauea east rift zone and Hualalai, it is critical to note that there are significantly more HELCO system constraints associated with adding generation in the east region of the island compared with the west region," HELCO officials wrote in the draft RFP.
HELCO on Nov. 9 launched the process to select a bidder or bidders to supply up to 50 megawatts of geothermal generating capacity. That would be in addition to the 38 megawatts already provided to HELCO by Puna Geothermal Venture. A single megawatt can provide enough power to supply the energy needs of about 650 Hawaii island homes.
HELCO’s 80-page draft RFP lays out specifications for the project and what potential developers will be required to deliver. The document includes a table laying out the geothermal potential for four areas on the island.
Of the total 1,396 megawatts of estimated generating capacity, more than half — 778 megawatts — is in the east rift zone, according to a consultant’s study quoted in the report. The other areas are the Kilauea southwest rift zone, 393 megawatts; Mauna Loa southeast rift zone, 125 megawatts; Mauna Loa northeast rift zone, 75 megawatts; and Hualalai, 25 megawatts.
Officials from Innovations Development Group, which bills itself as a specialist in socially responsible energy development, said they plan to bid on the project. The company is not ruling out any location on the island, including the Hualalai area, said Mililani Trask, a consultant working with IDG on its bid.
Trask said IDG will urge the Public Utilities Commission to act as expeditiously as possible in approving a bidder or bidders so that residents can enjoy the benefit of geothermal energy, which can produce electricity at a much lower cost than the petroleum-based fuels used for most of the island’s power.
HELCO’s timetable is to select a winning bidder or bidders by summer and have new geothermal facilities operating sometime between 2018 and 2023.
"IDG will be looking at ways to shorten that timetable," Trask said. "We’re dealing with a crisis on Hawaii island with the high electricity costs. Everyone needs to be marching double time on this."
Trask credited state Sen. Malama Solomon (D, Hilo-Honokaa) for pressuring the PUC to speed the RFP process. Solomon in October presented PUC officials with a petition signed by 1,200 Hawaii island residents urging the state and electric utilities to quicken the transition from fossil fuels.
Mike Kaleikini, plant manager for Puna Geothermal Venture, said the company has not yet committed to submitting a bid for the additional geothermal capacity.
"We want to take a look at what’s in the RFP. Once we’ve had a chance to review it, we’ll have something to say," Kaleikini said.
One of the main advantages of geothermal compared with solar- and wind-generated energy is that the steam from the geothermal wells produces consistent power similar to that of a traditional oil-fired power plant. Solar power is available only during daylight hours, and even then the electrical output of photovoltaic panels can vary, depending on cloud cover. Similarly, the energy produced by a wind turbine can vary with wind speed.
Another plus with geothermal is cost, with a state consultant estimating such power can be produced at a cost of 7 cents to 8 cents per kilowatt-hour. That compares with 21.8 cents per kilowatt-hour that HELCO has agreed to pay developers for solar electricity. (HELCO residential customers paid 40.4 cents a kilowatt-hour in October.)
However, prospecting for geothermal resources in Hawaii can be expensive, with the typical project requiring drilling of one or more test wells through layers of rock to depths of 6,000 feet or more.
