The road out to the PGV site passes through gigantic, airy forest. It’s a narrow and little-traveled highway, and the power plant itself, set on twenty-five acres, is hidden behind a rise. Inside the plant, pipes and cylinders run at ninety degrees to each other, most of them painted shiny forest green. The sound, undetectable at a distance, emerges as a whirring roar when you approach the plant’s ten major components, twenty-four-foot-tall energy converters standing in parallel, each producing three megawatts (MW) of electricity nonstop. (A megawatt is one million watts; it can, according to the US Department of Energy, meet the needs of about one thousand American-style residences.) The roar is a watery sound produced mostly by fans cooling steam.
This steam comes from wells that PGV has drilled here: shafts that wander in every direction in search of heated water. The wells drive down 3,500 to 7,000 feet below sea level seeking water that has percolated through the cracked and porous structure of the volcano and gotten trapped close to deep magma. Full of chlorides, very acidic and reeking of sulphur, this material shoots up at a rate of four thousand gallons per minute, powered by its own intense pressure. PGV’s pipes capture this force, separate the steam from the brine, then use the heat energy of both to spin turbines. These turbines cause electrical generators to turn and from that comes electricity, which travels to the HELCO plant and is then distributed to (for example) hotel rooms in Hilo. The spent steam and brine, meanwhile, return to the earth’s depths via injection wells.
What PGV doesn’t have is a huge smokestack—and that absence is historic because Hawai‘i, though it contains zero natural deposits of fossil fuel, currently depends on oil for a whopping 90 percent of its energy. Last year the Big Island alone spent a billion dollars on oil. Wallace Ishibashi, head of the ILWU Hawai‘i chapter and a longtime proponent of geothermal, asks: “What do you think is our biggest export from Hawai‘i? Bananas? No way. Our biggest export is our own money. That billion dollars we spend on oil, we can keep that here.” Can we?
Mike Kaleikini is the face and the managerial force behind PGV. Built to NFL proportions, the Kamehameha Schools graduate came to the PGV site in 1991 when the trenches were being dug. Today, clad in leather boots, jeans and a striped polo shirt, he serves me a cup of coffee in the PGV offices—minimal plywood structures that look as though you could pick them up with a forklift. In fact, the entire PGV plant is somewhat movable; it is, after all, located in a lava inundation zone. If a flow ever comes, components can be hauled away, wells capped and—if they’re not destroyed by the flow—later recoved via GPS coordinates. If one of the earthquakes that regularly rumbles through the region shears the wells, well, that would be a different story.
Kaleikini tells me what he wants everyone to know. The energy generated at PGV is “firm” or “base load”—that is, Mike explains, it doesn’t fluctuate the way wind, solar and some other forms of renewable power can. PGV is owned by Ormat Technologies Inc., an Israeli company that’s engaged in geothermal development around the world. Ormat helped launch PGV by providing “EPC services”—engineering, procurement and construction—and then bought the plant in 2004.