Workers plugging energy wells as lava flows nearby

PAHOA, Hawaii — Authorities were racing Tuesday to close off production wells at a geothermal plant threatened by a lava flow from Kilauea volcano on Hawaii’s Big Island. Workers were capping the 11th and last well at the plant to prevent toxic gases from wafting out after lava entered, then stalled, on the property near one of the new volcanic vents.

“Right now, they’re in a safe state,” Mike Kaleikini, senior director of Hawaii affairs for the Puna Geothermal Venture plant, said of the wells. There also were plans to install metal plugs in the wells as an additional stopgap measure.

The wells run as deep as 8,000 feet underground at the plant, which covers around 40 acres of the 815-acre property.The plant has capacity to produce 38 megawatts of electricity, providing roughly one-quarter of the Big Island’s daily energy demand.

Lava destroyed a building near the plant, bringing the total number of structures overtaken in the past several weeks to nearly 50, including dozens of homes. The latest was a warehouse adjacent to the Puna plant, covered by lava on Monday night, Hawaii County spokeswoman Janet Snyder told the Honolulu StarAdvertiser. The building was owned by the state of Hawaii, and was used in geothermal research projects in the early days of the site.

Puna Geothermal, owned by Nevada’s Ormat Technologies, was shut down shortly after Kilauea began spewing lava on May 3. The plant harnesses heat and steam from the earth’s core to spin turbines to generate power. A flammable gas called pentane is used as part of the process, though officials earlier this month removed 50,000 gallons (190,000 litres) of the gas from the plant to reduce the chance of explosions.