On one of the blazing screens of Valley Electric Association's control room in Pahrump, Nev., an image pops up of what looks like a glowing rail yard on Mars: Gunmetal train cars lined up on silver tracks, the whole scene set neatly on a shimmering brown slope. Valley Electric's CEO, Tom Husted, erupts with enthusiasm at the sight. "There it is!" he exclaims. "ARES. Heard of it?"
Pronounced like the name of the Greek god of war, ARES stands for Advanced Rail Energy Storage. The concept is simple: When excess power comes off an energy source that's not always available – solar, say, or wind – that power, rather than going to waste, is used to move the rail cars up a hill to a storage yard. Then, after the wind stops or the sun goes down, the cars descend, generating electricity via regenerative braking.
ARES is the new, new thing in energy storage. It has never been put to work on a full-size electrical grid. The world's first grid-scale system will be built about three miles northeast of Pahrump on a long alluvial fan coming down from the nearby Spring Mountains.
An unincorporated town of 36,000 in northern Nye County just east of Death Valley, Pahrump is not a place you'd expect to find an energy utopia; the very name evokes the sorrowful report of a circus tuba. In Paiute, however, the word means "water in the rock," a place with a plentiful desert aquifer, where the snow on distant Mount Charleston reflects the Mojave Desert's banded sunset. Valley Electric's territory, which stretches for nearly 7,000 square miles along Nevada's western edge, boasts some of the best clean-energy resources in the world: Sunshine beaming down on a mid-elevation desert; steady, perennial winds; sulfurous steam that wafts up from fumaroles in the chalky earth, sure clues to the geothermal bounty that lies beneath.
"We believe those natural resources in Nevada that are developed properly and responsibly can mean to Nevada what other natural resources are to other states," Husted says. In other words, Nevada could indeed become, to paraphrase U.S. Sen. Harry Reid, the Saudi Arabia of renewable energy.
A couple of years ago, Husted counted up his applications for interconnection into the 350 miles of transmission Valley Electric owns, and realized that 3,000 megawatts of renewable electricity was under development in the utility's territory. "Three thousand megawatts," he says. "That's two times the output of Hoover Dam." Obviously it wasn't all for Nevada's 2 million residents. "It was to get to the markets," Husted says, "and those markets are in California." So in early 2013, Valley Electric left the Nevada in-state electrical market and made its system data and circuits available to California's grid operators; the few hundred megawatts currently generated within its territory travel south to connection points near Las Vegas, where they blend into the system managed by the California Independent System Operator.
ARES could be the perfect complement to those wind and solar megawatts. Steven Greenlee, a spokesman for the California grid authority, describes the electricity market as a continuously circulating "infinity pool" that needs to be maintained at a certain level; that effort gets trickier as more intermittent resources come online. A storage scheme like ARES would be like having a large tank next to that pool, ready in case the level dips too low. California's utilities have been ordered to add storage to their infrastructure by 2016, the better to balance a grid buffeted by wind and doldrums, sun and clouds. ARES CEO James Kelly says he hopes to have the Nevada project online just in time.
The idea seems so simple. "I'm shocked no one has thought of this before," I tell Valley Electric's system operator, Clay Calhoun, a friendly, blue-eyed man in his 30s, brimming with enthusiasm for the slick technology around him. "That's how it works," he replies. "Sometimes people win Nobel prizes for incredibly simple inventions." The possibility was always there; someone just had to put the pieces together when the world was ready.