Making these giant batteries a widespread reality on the grid, however, requires presenting a compelling economic case to electric utilities. “The technology not only has to work. It has to work economically,” says Hoagland. He estimates it will cost $25 million, or $2,000 per kilowatt, to build the Columbus battery. That’s double the price of a new power line and diesel generators to back up the base. “They’ve got to be below $1,000 per kilowatt in capital costs before they’re going to be something the utility industry is really going to take notice of,” Hoagland says.
One thing sure to get the attention of power system operators is the potential of flow cells to save and even earn money by optimizing the use of existing power plants and lines. The Tennessee Valley Authority’s studies show, for instance, that flow cells can pay back $250 per kilowatt per year if the cells enable power companies to buy electricity at a low price, store it, and later sell it at a higher price, while simultaneously providing power reserves and some stability control to local power lines. And in such congested electricity markets as Pennsylvania, New Jersey, and Maryland, deferring construction of a new power line by installing a flow cell instead could save more than $1,000 per kilowatt per year, says Joseph Iannucci, principal with Distributed Utility Associates, an energy consulting firm in Livermore, CA. By unclogging transmission bottlenecks while simultaneously playing the power markets, flow cell operators could not only make the technology practical, but also earn $4 billion in revenue annually in the United States alone, Iannucci maintains.
It sounds great, but the current regulatory climate is still murky for flow cells. Deregulation is separating the business of power generation from the business of shipping and distributing electricity, but the business of energy storage falls in a gray area somewhere between those two. Giant batteries affect distribution by unclogging bottlenecks on the lines, but they also act like power generators, supplying markets with cheap electricity from their stash of stored power. “Under the present uncertain semi-deregulated situation, it is very difficult to ask a utility to spend $25 million or $100 million on a storage system which tomorrow it may not be allowed to own,” says American Electric’s Nourai.
Nor is there much incentive for new entrepreneurial players to build flow cells. That’s because deregulation has not yet introduced true competition in the transmission and distribution business. Upstarts who challenge the power industry with flow cells could easily be thwarted by the monopolies that control the power lines. “Even if my numbers show that the markets would be worth billions, who is going to take that risk?” Iannucci asks.
Much as they initiated competition in the power generation business in the early 1990s, federal energy regulators are now writing new ground rules that would unleash competition in the transmission markets. The regulators might, for instance, raise the cost of sending power through the most congested regions of the grid. Such so-called congestion pricing would stimulate investment in flow cells to relieve those costly bottlenecks.
Despite these uncertainties, there’s little doubt giant batteries are coming. Favorable federal regulation could get them here sooner, but they’ll get here in any case, says Imre Gyuk, who manages the U.S. Department of Energy’s energy storage research programs. “As we get more and more congestion and it becomes more and more difficult to build new transmission lines, and as environmental constraints become greaterthere will be a price crunch,” says Gyuk. And then even the most costly grid battery will look attractive to transmission operators, he adds. “What is the price of air when you’re being hanged? Or when you’re drowning?”
Such morbid analogies don’t sound too extreme to the engineers at Columbus Air Force Base. Last November two tornadoes tore through Columbus, shredding power lines and houses and plunging the city into 48 hours of darkness. The base lost power for three hours. That’s not too long for most homeowners, but when it’s a question of keeping jets aloft, three hours is an eternity. The base commander, Colonel Stephen Schmidt, says it seemed longer with the lights out, warning sirens inoperable, and no way to know when the next tornado might hit. “It would have been awesome if we’d been able to keep the power on,” he says. In Columbus, at least, that ability is coming soon.
Battery Power for the GridCOMPANYPROJECTTECHNOLOGYSaft (Bagnolet, France)Supplementary power source for Fairbanks, AKArray of nickel-cadmium batteries to help provide steady voltage and supply energyVRB Power Systems (Vancouver, Canada)Backup power supply
for Castle Valley, UTVanadium flow battery in lieu of upgrades to a 190-kilometer transmission lineZBB Energy (Menomonee Falls, WI)Solar-power delivery in White Cliffs, Australia
Zinc-bromine battery to store and deliver power from remote solar-power stationActive Power (Austin, TX)Protection from faulty
power in Rousset,
FranceFlywheel batteries to protect semiconductor factory against voltage fluctuationsRegenesys Technologies (Swindon, England)Steady, reliable power source for Columbus, MS, and Little Barford, EnglandFlow battery using sodium bromide and sodium polysulfide to provide backup electricity