Who among us has not twitched a little during this, the year of California’s power crisis, upon hearing Tales of the End Time of the Fossil Fuel. For more than a billion years, the planet’s organic matter has laid down its life to form combustible sumps of oil, gas, and coal. And now, petroleum engineers predict, the cache is dwindling — lo, accelerating its dwindling — as we dig and siphon more of that cache every day. Here is the prognosis again, in case you missed it. At present rates of consumption, recoverable world coal reserves will last no more than 1000 years. U.S. coal reserves will last us 275 years. Recoverable world oil and natural gas reserves will last between 100 and 200 years. U.S. oil and gas reserves, between 50 and 75; that is, without Alaska and without West Coast offshore drilling. Such temporal abstractions leave most Americans unmoved. What drives us is not the reckoning with what’s left but the challenge of getting at it. That we’re good at. From oil rigs crowding the Gulf of Mexico to vast coal-mine pits in the Midwest, we have a century-long record of developing technology to recover what’s recoverable with scant development of renewable sources like solar power.
For the moment, let’s forget technology and its hold upon us. In terms of supply alone, there is one energy source — renewable and recoverable — whose reserves dwarf projections for oil, gas, and coal: geothermal energy, which exists as heat, hot water, and steam buried in the earth. In the upper six miles of rock beneath the contiguous United States, there is approximately 6000 times the energy contained in the world’s oil reserves. Six thousand times more. Since geothermal energy has no CO2 emissions and is almost entirely renewable, this may as well be forever. The multiple reaches its apogee because water, the conveyor of geothermal heat, is self-renewing.
What is San Diego’s connection to the heat beneath? Beyond the gentle mountains of our coastal range lies the Colorado Desert and its centerpiece, the Imperial Valley. Underneath the Valley’s half-million acres, which on the surface is a below-sea-level, furnace-hot, irrigated paradise for agriculture, there’s a reclusive geologic giant, water boiling deep in the cauldron of the Salton Trough, hot enough to supply an epoch of energy needs. The trick is, of course, to get the heat out. Plumbing the trough’s depths are three multiplant geothermal-power operations — one east of Holtville on the Valley’s East Mesa, going toward Yuma; one in Heber, south of El Centro; and one north of Westmorland, a gull’s quick commute from the Salton Sea. Groundwater a mile down, heated by the magma, is brought to the surface and sent through an intestinal array of pipes, pressures, and processes that spin turbines and generate volts. Once spent, the geothermal fluid, or brine, is returned to its underground reservoir via injection wells, a cyclical dance that on a grander scale might make the Saudis nervous. But geothermal production is hardly full-blown. The Valley is making 540 megawatts of electricity, enough to power 540,000 homes. Valley generators do not sell to San Diego Gas and Electric — still, at 2.5 people per home, 540 megawatts represents nearly half of San Diego County’s residents. Twelve percent of California’s electricity comes from renewables like small hydroelectric, biomass, wind, solar, and geothermal. The fossil fuels rule now, but the renewables are the future.
Eighteen miles southeast of Mexicali, Mexico, is Cerro Prieto, the world’s third-largest geothermal field. Its three plants make 600 megawatts of electricity for northern Baja. I received permission by phone to visit the plant from a woman at the visitors’ center who said, “Please come. A man will show you around.” I sent a letter, outlining my journalistic business, and a geologist friend and I drove the 135 miles. At the plant gate, we were pointed from one guard-in-a-little-house to another with ¿Qué quieren ustedes? until we were told the interview and tour were canceled. Back home I got a terse e-mail from the woman saying that according to Mexico City headquarters, Comisión Federal de Electricidad, access to control rooms and wellheads was denied. Since then I’ve learned the probable reason: The state-owned electric utility rarely monitors its pollution. Apparently Cerro Prieto’s energy jefes don’t want any journalist investigating the plant, especially now that Baja is exporting power to the United States.
Sergio Cabañas is a solemn-faced man with distinctive wisps of gray in a black mustache. He’s formal and confessional, moving easily from one temper to the other. An environmental engineer with Covanta Energy in Heber, he is also a son of the border. Cabañas, like much of the Imperial Valley’s history, embodies that memorable line of poet Guillermo Gómez-Peña: “The border is the juncture, not the edge.” Born in San Diego, Cabañas was raised in Mexicali, Mexico’s ever-booming Valley border town. Owning dual citizenship, he returned for high school to Calexico, Mexicali’s sister city on this side. (Partaking of each other’s name exemplifies juncture.) Cabañas describes himself then as “miserable,” because he didn’t fit in. There was a backlash from “my own people. I was not a lowrider; I was not a cholo.” He was more dedicated to study than, as he says, some of his Chicano brothers “over here.” Disgruntled, he enrolled in Mexico City’s Universidad Nacional Autónoma de México, one of the oldest and largest schools in the Americas. With a degree in biochemistry, Cabañas returned to Mexicali just in time for (what seems) the peso’s decennial devaluation: A cousin working at Vons in Calexico was making more money than he was as a freelance chemist.
In the late 1970s, the bilingual Cabañas again studied biochemistry, this time at San Diego State, for two reasons. He needed to take additional courses in California to have his Mexico degree recognized for employment here, and he hoped to get up to speed with biochemistry’s newest technology. He half-smiles, remembering the atomic absorption machine at State, “right out of a movie and a mad scientist’s lab.” But, to continue, he needed a school loan. With a large check in hand he asked his counselor, “What do I do with this?” Pay for your books, tuition, rent, he was told. In class, when Cabañas saw the girls at State, he thought he’d “died and gone to heaven.” In Mexico, students dress formally for class; in San Diego, both sexes sometimes show up in bathing suits. The shock of easy money and drafty clothing was too much. “That first year, I used to sit down and cry,” he remembers. “Did I make a mistake by leaving Mexico?”