Solar power is a clean, renewable source of electrical energy. But in order to extend the time this energy is available, an energy storage system is needed. As reported by Eric Wesoff for greentechmedia, the California Public Utilities Commission has granted $1.8 million to SunPower Corporation to demonstrate how solar power and energy storage technologies can be integrated. SunPower will work with energy storage systems provided by Ice Energy, Xtreme Power, and ZBB Energy Corporation to deliver power to Target stores in California.
Ice Energy, headquartered in Windsor, Colorado, will use its Ice Bear technology in the project with SunPower. As explained by Ice Energy, its Ice Bear unit works with standard air conditioning units. During its ice charge mode the unit freezes water in an insulated tank by pumping refrigerant through copper coils. The ice is stored until cooling energy is needed. Then when temperatures rise and cooling energy is needed, the unit switches to cooling mode. The stored ice is used to cool the refrigerant rather than the air conditioning unit’s compressor unit, saving electricity.
Xtreme Power, headquartered in Kyle, Texas, provides an XP system for managing the distribution of solar energy. When solar photovoltaic panels generate more power than is needed locally, the power is fed onto a distribution line and the grid can potentially be disrupted. The substations of the XP system act as a buffer between the grid and the solar panels. Excess solar power is absorbed and the grid is fed a smooth and steady stream of power. The XP system communicates with the grid, measuring power levels and automatically makes the necessary adjustments. Power is stored during the day when solar power is at its peak and the energy is released later.
ZBB Energy Corporation, based in Menomonee Falls, Wisconsin, will provide zinc bromide battery storage technology for the California project with SunPower. The Zinc Energy Storage System (ZESS) 500 will be used for this commercial application. The ZESS 500 is actually a series of ten connected ZESS 50s, each of which could power an average home for two days. The ZESS 500 holds a total of 500 kWh, fully charges in four and a half hours, and has continuous power of 250 kilowatts that can be sustained for two hours. The unit weighs approximately 30,000 pounds and can be transported on a 20-foot trailer. Since the design is modular, the ZESS 500 can be adapted for different power needs. In addition to solar panels, the system is compatible with other renewable energy sources, including wind, solar, hydroelectric, ocean power, biofuels, and biomass.
Eric Wesoff, “SunPower Working on Solar Plus Energy Storage” – Greentechmedia
California Public Utilities Commission Funds ZBB Energy and SunPower Demonstration Project of Renewable Energy With a ZESS 500 – marketwire
ZBB Energy Corporation