Fire shuts off
Big Isle power plantA facility spokesman says
no one was hurt and no
geothermal steam was released
PAHOA, Hawaii >> Leaking pentane caught fire yesterday at the Puna Geothermal power plant south of Hilo, knocking the plant offline temporarily, owner's representative Barry Mizuno said.
The damage was limited, no one was injured and no geothermal water or steam with smelly hydrogen sulfide gas was released, Mizuno said.
"We are grateful that no one was injured in the incident," he said.
The plant produces nearly a quarter of the electricity for the island.
The incident took place shortly before 11 a.m. when high winds were causing power failures on the island.
Mizuno said he could not rule out a connection, but there was no immediate sign of a link.
There was no indication of a wind-blown object causing damage, he said.
The power plant is divided into 10 generation units, each rated at 3.5 megawatts, Mizuno said. One was out of service for repairs, and yesterday's incident involved one of the remaining nine.
Each generator consists of a turbine that spins an electrical generator using geothermal steam, plus a second turbine powered by pentane, a petroleum product, heated to a gaseous state by residual geothermal heat, he said.
Pentane from a unit called OEC 21 caught fire, resulting in a small explosion, he said.
"It just popped. The heat made it pop," he said.
The fire was brought under control in about an hour, he said.
Fire Capt. Pomai Wela said fighting the initial fire was easy using foam mixed with water. The danger was that the pentane would reignite because it is so volatile, he said.
He described each generator unit as about 15 feet high and 35 feet long.
Mizuno said four units were restored to service by the afternoon.
Checks were being made on units near the damaged one, although there was no indication they were affected by the fire. They did not even have scorched paint, he said.
Damage to the environment was prevented by cutting back on the geothermal liquid piped out of the ground, he said.
"The problem with geothermal fluid above ground is to get rid of excess heat before putting it back into the earth. That is done with large fans," he said. The geothermal fluid in pipes is never exposed to the air.