Scientists are set to begin testing for geothermal energy potential on Oahu and other Hawaiian islands. And what they find could change the direction of Hawaii’s energy policy.

Tests conducted several decades ago, show that the thermal energy lying below the Big Island’s volcanic rifts is enough to power the state’s electricity needs seven times over, according to a report by the Massachusetts Institute of Technology.

The newest of the Hawaiian islands, where hot lava still erupts from the Kilauea and Mauna Loa volcanoes, has been a natural focus for developing the resource. The Big Island is the site of the only geothermal plant in the state, run by Puna Geothermal Venture.

But the old studies show that lower-intensity resources exist on Maui and Oahu. And new technology that is better able to test for the resource could prove that the islands are also good locations for development.

Already, Ormat Technologies, the parent company of Puna Geothermal Venture, is exploring geothermal on Ulupalakua Ranch on Maui.

But on Oahu, there has been scant interest. The studies show that the resource isn’t enough to generate electricity for the island, according to Mililani Trask, an advisor to Innovations Development Group, which has been working to develop geothermal on the Big Island. However, Trask says the company has been looking at the potential for tapping geothermal in the Waimanalo area to power agricultural operations.

The new studies could aid developers in harnessing geothermal throughout the state. And if sufficient sources are found on Oahu for a power plant, it could change the energy mix for the island, which is home to the majority of the state’s population and has the highest energy needs.

Don Thomas, a geochemist and director of the University of Hawaii’s Center for the Study of Active Volcanoes, will be leading a team in the coming weeks composed of university researchers and scientists from the Lawrence Berkeley Lab, aided by $2 million in state funding and royalties from Puna Geothermal Venture.

“The technology we used quite a number of years ago, in terms of doing exploration has improved tremendously,” he said. “I think we have much better technology now to at least identify areas that have potential.”

On Oahu, Thomas’ team will be focused on exploration around the island’s dormant Waianae and Koolau volcanoes. Testing is expected to take place on the leeward side, around Lualualei Valley, and in the Kapaa area, and should be completed in about two years, said Thomas.

The state’s energy policy has taken various twists based on changing market conditions for renewable energy, political pressures and state regulatory rulings. Big Wind— a key part of the state’s renewable energy plan — hit significant snags last year. Biofuel companies have struggled while solar continues to soar. And pre-commercial, ocean thermal energy conversion, which could potentially power all of Oahu, continues to have a hard time with funding.

Amid this, and increased political pressure to move the state off oil as electricity prices remain at triple the national average, geothermal has sparked renewed attention. In recent years, leaders on the Big Island have thrown their support behind future development. And a plan hatched in the 1970s to bring geothermal energy from the Big Island to Oahu via undersea cables has attracted new interest.

But if geothermal potential is found on Oahu, depending on its quantity, it could make it unnecessary to connect the islands. The ocean shelf off the Big Island has a steep drop and engineers have worried about whether a cable is even feasible.

The state has argued that unless neighbor island resources are tapped and shared with Oahu, Hawaii will not be able to meet its clean energy mandate, which includes 40 percent renewable energy by 2030.

Hawaiian Electric Co. spokesman Peter Rosegg said it was premature to talk about what could happen if resources are found on Oahu. HECO provides electric service to all of Oahu and most of the neighbor islands. Kauai is the only island with its own electric utility.

“It would hardly be wise to speculate on the outcome of research that has not even begun yet,” Rosegg said by email. “Hawaiian Electric remains committed to getting Hawaii off our over dependence on imported oil through a wide variety of renewable energy sources including wind, solar, waste-to-energy, biofuels, hydro, ocean energy and geothermal energy where it is available.”

Thomas emphasized that there’s no guarantee that significant geothermal resources will be found on Oahu. While there was tremendous heat when the volcanoes were active, he said, it’s been at least a couple of million years since they were active and it’s not known how fast the heat has dissipated.

“With more sophisticated technology, there’s going to be a realistic and concerted effort to determine whether there are viable resources on Oahu, or not,” he said. “The work we did back in the late 1970s did show some encouraging indications. But in the context of today’s technology the tools we had were pretty crude. I really try to caution everyone that we really have some data, but it is too soon to say definitively that we have a resource or do not have a resource.”


Do you think more focus should be placed on developing geothermal on Oahu if tests shows it could be viable?

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