It’s a thrifty trick used by households from L.A. to Luxembourg, or anywhere where utilities charge less for electricity during off-peak hours. You load the washer and drier during the day and turn it on before you go to bed, when cheap power kicks in.
But what if you could take the scheme to the next-level, store off-peak electrons in a powerful battery and use them to power your home during the day, when price per kilowatt-hour hits the roof?
“This technology could give customers control over what they want to do and when,” Chris Todd, an engineer with Princeton Power Systems (PPS). “It could also help utilities balance demand and shave peak electricity loads during the day.”
Such systems are now coming to light. Todd was part of a team that just linked Princeton Power’s advanced power management technology to GE’s next-generation Durathon batteries at L.A.’s Discovery Science Center in Santa Ana, Calif. The system will help the non-profit shift between 10 to 20 percent of its daily electricity demand from peak rates to less expensive off-peak power. It will also serve as backup during power outages. “This type of project can demonstrate that battery-based load-shifting technology is a viable tool for customers to respond to demand and permanently shift a significant percentage of daily electrical loads to non-critical hours,” says Prescott Logan, general manager at GE Energy Storage.
PPS makes the technology that “inverts” direct current stored in the batteries to alternating current needed in the sockets, and vice versa. The system uses data gathered from the science center’s smart meters and other sensors and feeds it into a set of algorithms to determine the most economical time for battery discharge and recharge. “The algorithms are gathering real time data about what’s happening in the building,” Todd says.
The Durathon batteries at the center can store 500 kilowatt hours, enough to reduce its electricity bill and keep the lights on for several hours when power goes out.
The project is part of California’s Permanent Load Shift program, a statewide effort to reduce peak demand on the California electrical grid. The joint Princeton Power and Durathon design won Southern California Edison’s request for a cost-effective solution to shifting the center’s power load.
Similar systems are still too expensive for the home. But the technology is evolving fast. “Unlike traditional, thermal-based energy storage technologies, battery-based energy storage systems can be used by a much wider range of customers,” GE’s Logan says. “We believe there is a huge potential for solutions like the one we’ve been developing with PPS across North America and worldwide.”
