A controversial geothermal power plant that supplies about a quarter of the Big Island’s electricity was forced to shut down as lava from Kilauea Volcano threatened the property.

Now opponents want to keep it closed — permanently.

No one knows whether the 38-megawatt, $100 million-plus Puna Geothermal Venture facility will survive Kilauea’s lava flows, which surfaced in an adjacent residential community May 3. But the ongoing eruption triggered the shutdown and led company officials to secure the plant’s wells and remove a large volume of flammable gas.

The lava eventually crossed onto the company’s property and already has overtaken two wells, blocked the main access road and burned a substation and adjacent warehouse where a drilling rig was stored, according to a PGV update issued on Thursday.

But even as the older lava cools and newer flows emerge in surrounding areas, the debate on what happens to the 25-year-old facility is expected to get hotter and more intense in the weeks and months ahead.

A Steady Source of Power by Honolulu Star-Advertiser on Scribd

Opponents say the lava encroachment underscores what they warned of years ago — that a geothermal facility that generates steam containing dangerous gases should not be built less than a mile from residential communities and in a rift zone on one of the most active volcanoes on the planet.

Residents who live about a half-mile away say they have been sickened over the years by gas or steam releases from the plant and claim PGV never alerts them when something happens.

“It’s been a horrible neighbor,” said Mike Hale, 48, who lived in Leilani Estates for the past 18 years but lost his home last month to the lava.

Even if Kilauea’s assault doesn’t destroy the PGV plant, the lava infiltration so far shows that no geothermal facility should be operating there and that the existing one should remain idled, opponents say.

“This tragically shows we have been proven correct in our concerns in the worst possible way,” said Sen. Russell Ruderman, who represents the Puna area, and has participated in the anti-geothermal movement since the 1970s and was among those arrested at a protest around 1990 before the PGV plant was fully operational.

Supporters, however, say opponents are spreading misinformation about the facility and that the technology for tapping underground steam and hot water via deep wells is considered safe.

“There are many in the community who use fear-mongering as a tactic against a variety of resources here,” including geothermal, said Bill Walter, president of the Hawaii Island Chamber of Commerce.

Richard Ha, who has been involved with Big Island agriculture for the past 40 years, said he disagrees with the position that the PGV site should be permanently closed. “Geothermal is a resource that we should use,” he said. “The closer you are to the rift zone, the more steam you get.”

Walter, Ha and others view geothermal as part of the answer to weaning Hawaii from heavy dependence on fossil fuels, describing it as reliable, cheap and safe. The PGV plant taps the underground steam and hot water to power turbines that produce electricity.

Facility’s future unclear

Officials with PGV and Reno-based Ormat Technologies, the majority owner, did not respond to Honolulu Star-Advertiser requests for comment.

But in written statements last week, Ormat said it cannot assess when the Puna complex will be able to resume operations.

The company said the lava was continuing to flow and may reach other wells and areas of the property. Ormat said it has $100 million worth of insurance coverage for volcanic eruptions and earthquakes.

One geothermal expert said questions about the fate of the PGV site could take years to be fully answered.

“The operators of the Puna plant have difficult decisions to make,” Wilfred Elders, an emeritus geology professor and former director of a geothermal resource program at the University of California in Riverside, wrote in an email to the Honolulu Star-Advertiser. “They have a big capital investment and no revenue. Until this phase of Kilauea’s eruptive cycle ends, and the Puna rift zone is quiet, they cannot think of redrilling the wells they lost. It is even conceivable that lava could overwhelm the power plant itself.”

Since 2008 the geothermal facility has supplied an average of 22 percent of the Big Island’s power needs, according to data from Hawaii Electric Light Co., which operates the Big Island’s power grid and produces the bulk of the electricity. HELCO has a contract to purchase power from PGV.

Last year and through April of this year, the Puna plant generated 29 percent of the island’s power, a high for the decade, according to the utility’s data.

HELCO says it has the capacity to make up for the geothermal power loss indefinitely.

Safety violations

The PGV facility has been criticized over the years for releasing hazardous gases, including hydrogen sulfide. The most serious incident came in 1991 when one of its well’s had a major blowout. The uncontrolled venting lasted 31 hours and triggered the evacuation of nearby neighborhoods.

More recently, the U.S. Environmental Protection Agency fined PGV $76,500 for safety violations of the Clear Air Act. An August 2013 inspection, which was triggered by hydrogen sulfide releases in March and April of that year, found that the company failed to take necessary steps to prevent accidental releases, according to the EPA.

The agency reached a settlement, including the fine, with the company. At the time the settlement was announced in January 2016, the plant was in compliance with the act, EPA said.

A year after the EPA inspection, residents dealt with another release of hydrogen sulfide — this time as Hurricane Iselle was bearing down on the Big Island. Civil Defense advised residents to evacuate the area if they were not feeling well, but by then downed trees blocked the routes out.

In the hours and days following that release, residents reported symptoms including headaches, grogginess, shallow breathing, scratchy throats, nausea and fever.

The state fined PGV $23,700 for that release, which the company said was necessary because of downed transmission lines.

Too close for comfort?

Though hundreds of geothermal plants internationally are located in volcanic regions, several geothermal experts told the Star-Advertiser they were not aware of an eruption closing one down. They also said they were not aware of plants being built within a mile or so of residences.

Ruderman, the state senator, said no other geothermal plant in the world is located as close to homes as Puna’s.

“When looking at recent images of the (Puna) lava flows, I was quite surprised at how close the geothermal plant was to houses,” Martyn Unsworth, a geophysics professor at the University of Alberta in Canada, wrote in an email to the Star-Advertiser.

At plants he’s visited in Iceland, the Philippines, Mexico and Japan, the nearest homes were several miles away and often much farther, Unsworth said.

Roland Horne, a Stanford University professor of energy resources engineering, said he wouldn’t have reservations about siting a geothermal facility around a highly active volcano.

“Geothermal plants work best where it’s hot, so a volcano is kind of a good place to put them,” Horne said in an Q&A published on Stanford’s website.

But opponents of the PGV plant say the ongoing Kilauea eruption has brought more public attention to the problems of having a geothermal facility there, adding momentum to a movement against restarting the PGV operation.

“They’re dead,” Leilani Estates resident Sofia Wilt said of the plant. “People are angry.”

Wilt bought her home in 2007 but lost it to lava last week.

If the lava doesn’t claim the plant, people will not tolerate attempts to revive it, taking to the streets if necessary, according to Ruderman.

“If you thought we had protests back then, wait til you see what happens if they try to restart,” he said.