In a small storage container on a hilltop overlooking San Diego sits an unprepossessing fuel-cell technology that could have a powerful effect on utility operations. Inside a substation at San Diego Gas & Electric Co.'s Mission Valley facility in the northeast part of the city, the fuel cell system, from Israeli developer GenCell, is being readied to help reduce the duration of power outages by powering the battery racks at individual substations when the grid goes down.
"You can see what happens when the power goes down," said GenCell founder and Chairman Gil Shavit, during a Feb. 2 demonstration. "Nothing. There is no sound and no vibration. The only way you can tell it's running is by the water being produced by the system."
First developed in the 1830s, fuel cells make electricity by combining hydrogen and oxygen atoms to make water, releasing electrons in the process. The GenCell system being deployed by SDG&E consists of a 5-kW fuel cell, a heat exchanger, and a computerized control and monitoring system, all of which fit inside a 9-foot-by-8-foot shelter. Tall slender hydrogen tanks supply the fuel for the fuel cell. The system can supply power to the substation for up to 24 hours, replacing the diesel generators that feed the batteries in a typical set-up.
SDG&E announced at the DistribuTech conference in San Diego that it has ordered 30 of the units, to be deployed at substations over the next three years. Supplying clean, low-cost electricity to keep the substations' control systems and breakers operating during an outage, the GenCell systems will slash recovery times and allow immediate restarts once power starts flowing over the grid again, "turning 24-hour outages into 7-hour outages," according to GenCell Director of Marketing Adam Lahav.
Fuel cells have been touted in both stationary and transportation applications for many years, but their expense and the difficulty of creating an expansive hydrogen supply network has constrained adoption. GenCell said it has lowered the cost of its system by eliminating costly platinum from the fuel cells themselves and by enabling them to run on industrial-grade hydrogen, rather than more expensive medical-grade. And the backup power solutions being adopted by SDG&E, said Shavit, are "only a rehearsal" for the main act: helping integrate renewables onto the power grid.
"This is a game-changer for utilities' operations," said Shavit. "But the game-changer for our lives will be to create a virtual power plant on demand" by using distributed fuel-cell networks to supply power at the transformer level and at individual customer sites, all controlled from a central network operations center, when power from variable renewable sources, such as wind and solar, is unavailable. "This is the real story," he added, "targeted energy dispatch that creates an energy cloud."
List price for a single 5-kW GenCell system is approximately $100,000, including installation, according to the company. Each hydrogen tank, which contains enough hydrogen to run the cell for about 10 hours, costs about $100 including transportation.