In 1881, King David Kalakaua of Hawaii and his entourage paid a late evening visit to Thomas Edison in New York. The king was unsure about electricity — he didn’t think the technology was reliable enough to light up Honolulu’s streets just yet — but after marveling at a chandelier buzzing with electric light, the group started bantering about how Hawaii could generate power. What about putting boilers atop a volcano? There was enough energy up there, a companion to the king mused, that it could illuminate the entire United States. He appeared to be joking, but Edison took the notion seriously. Nice idea, he told his visitors, but an undersea cable carrying power to the mainland would be far too expensive.
Honolulu got its new streetlights a few months later — powered, in the end, by a hydroelectric dam. The volcano thought would wait a century longer.
In the 1970s, geologists began drilling into the eastern rift of the Big Island’s Kilauea volcano, resulting, in 1993, in Hawaii’s first geothermal power plant, which is today called the Puna Geothermal Venture, or PGV. The 38-megawatt facility straddles the most active rift of Hawaii’s most active volcano and is, to this day, the state’s only geothermal plant, supplying just 3% of the islands’ energy. That status quo puzzles geothermal advocates elsewhere. The obvious comparison is to a volcanic sibling like Iceland, where the Earth’s radiant heat supplies 25% of the country’s consumer electricity needs and more than 70% of its overall energy.
“It’s been talked about for ages that at some point, Hawaii needs to have a reset on geothermal,” Mark Glick, Hawaii’s Chief Energy Officer, told me. “That time is now.” So far, that reset involves the governor’s office directing discretionary COVID relief funds with the aim of getting an essentially moribund industry off the ground. Five million dollars will go toward a drilling program to explore the geology of promising areas of heat, hopefully with results that encourage potential developers to make their own, bigger investments. Site selection is underway, with Maui and the Big Island at the top of the list, and Glick said local outreach will begin in the next few months.
That the vast underground heat resources of a place like Maui are only now getting even basic attention is “mind-boggling,” Glick said. But it’s also a reflection of decades of turmoil over all things geothermal in the state — clashes with neighbors, toxic incidents, failed dreams of grandiose infrastructure. That has to change, he added, if the state is serious about ditching its dirtiest forms of power generation quickly. Hawaii has committed to reaching a 100% clean energy portfolio by 2045, but was still producing as much as 80% of its electricity from burning petroleum by last year.
Like other states endowed with abundant heat, Hawaii was previously inspired to consider geothermal energy during the 1970s oil crisis. The state was dependent on imported fuel, and the regularly lava-spewing Kilauea, in particular, looked like “a no-brainer” for geothermal development, explains Roland Horne, director of the Stanford Geothermal Program and a noted historian of the industry.
Hawaii’s problem is that, in addition to being an island chain, it’s also a chain of separate electric grids. With no power lines connecting the Big Island — home to 14% percent of the state’s population — to any others, Kilauea’s energy was marooned. Initially, the state imagined unifying its disparate grids in parallel with geothermal development. But Edison, it turns out, was right about undersea cables, even relatively short ones. After a decade of planning and testing that included laying prototype wires across the 6,100-feet deep, 30-mile wide ‘Alenuihaha Channel between the Big Island and Maui found that such a project was technically feasible but would be far too expensive.
Meanwhile, oil prices fell, and so did interest in hunting for hot rock elsewhere. Although a statewide survey that began in the 1970s found most of the islands could harbor geothermal resources — even older, geologically colder islands like Oahu and even Kauai — nobody followed up. “It led to almost nothing for three decades,” said Nicole Lautze, a geologist at the University of Hawaii-Manoa who is overseeing the state’s current exploratory projects. Instead, the state remained dependent on imported oil.
Other problems were more island-specific. Drilling into an active volcano is fairly unusual for geothermal prospectors and presents unique challenges, given the proximity of lava and abundance of toxic gasses. The work on Kilauea was controversial from the start, with nearby residents and Native Hawaiian spiritual practitioners calling the project not just unsafe but sacrilegious. A release of hydrogen sulfide during construction in 1991 only added to the controversy.
Toxic emissions, including sulfur, from geothermal facilities are generally minuscule compared with fossil fuel plants—and part of the everyday dangers of living on a volcanic slope, Horne told me. “They were coming out of the ground long before Puna was ever built,” he said. But PGV’s reputation as a danger to the community was hard to shake. When geothermal has made headlines in the state over the years since, the story has generally been PGV’s uneasy relationship with the volcano — most notably during Kilauea’s 2018 eruption, during which the plant was totally surrounded by lava flows. Neighbors remained fiercely opposed to the plant when it reopened two years later.
In 2014, when Lautze was tapped for a new survey of that state’s geothermal resources, the word “geothermal” was so taboo that she was reluctant to tell anyone locally her line of work. But she had funding from the U.S. Department of Energy, thanks to the federal government’s resurgent interest in geothermal as a source of clean, firm energy. Popular perception in Hawaii held that the Earth’s heat could only be tapped on the Big Island, where magma was breaching the surface, but Lautze was intrigued by the possibility of finding resources on islands that are less geologically volatile and home to more people. She set about developing new simulations for subsurface heat across the state, followed by on-the-ground experiments.
On islands like Lanai and Maui, Lautze said her team received a warmer welcome than expected. Certain benefits of geothermal had become much more clear amidst the state’s rush to adopt renewable energy — among them, that geothermal power would take a fraction of the land required to produce the same electricity from wind turbines or solar panels, in addition to providing continuous power, regardless of the weather. “Hawaii is realizing that they’re not going to get to 100 percent renewable from solar and wind alone,” said Lautze. Plus, she added, “the cost of energy is going up and up and up.”
The next step toward tapping that heat is what’s known as “slim hole” drilling, using bits less than 7 inches wide to descend more than a kilometer down. Even promising hotspots can be duds, and developers are often hesitant even in well-mapped places, which Hawaii isn’t. Before the state tries to sell geothermal companies on the idea of coming to Hawaii, officials want to be sure of what they’re selling. “There’s an absolute dearth of information on the volcanically older islands,” Lautze said.
Mike Kaleikini, head of Hawaii affairs for Ormat, which owns PGV, told me he’s been heartened to see the state turning its attention to basic research. Developers could very well get excited about places like Maui, he said, with some initial exploration already done and if they feel they can navigate permitting and potential concerns from the public. “Hawaii is not the easiest place to do business,” he added.
Among the better prospects for new development is on Big Island land owned by the Department of Hawaiian Home Lands, an agency that works to redistribute homes and land to Native Hawaiians. Located on the more docile slopes of Mauna Kea, the project’s backers say it could both power DHHL’s housing developments and generate royalties that help finance more home building.
Whatever heat developers strike there will remain marooned on the Big Island, at least for now. Channeling the dream of near-endless volcanic energy, Glick’s office proposed tying the Big Island’s geothermal production to a regional hydrogen hub so that the energy could be shipped offshore, but the DOE ultimately passed on funding the plan. Lautze still dreams of wires strung across the unruly Hawaiian channels. People still talk about the idea, she noted, even if it elicits smirks and eyerolls from people who lived through its past failures. The state is still a far cry from achieving the king’s dream. But the only way to get there is to start drilling.
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