Meet the Ice Bear. No, its not a cousin of the polar bear living in the Arctic. Its a big machine that uses a system of coils, 450 gallons of water and another evaporator coil. It was created by Ice Energy, tested by the energy provider Southern California Edison and can be added to a buildings air conditioner to store electrical energy as ice. And many of them may be moving to California.
Last October, the California Public Utilities Commission ordered its three big investor-owned electric utilities Pacific Gas and Electric, Southern California Edison and San Diego Gas and Electric to start storing electricity.
Its the first energy storage mandate in the U.S., and it requires the companies to build enough capacity to store 1.3 gigawatts of electricity, enough to power one million homes, by the end of 2020.
Storing electricity is expensive and inefficient because of energy loss through its conversion from storage to usable form. Design constraints also prevent large amounts of electricity from being stored. Big electric companies have turned to technologies to ease the process, and one of these is the Ice Bear.
The Ice Bear works by freezing water during the night, when electricity is less expensive and in less demand. While the rest of the building is sleeping (or at least not using power) a refrigerant runs through the coils of the Ice Bear to freeze the water. The next afternoon, when air conditioners may be at their peaks, a pump in the Ice Bear send the refrigerant, cooled by the ice it created, into the air conditioners evaporator coil. This helps cool hot air thats coming from the building. This newly chilled air is then pushed into the building, just as an air conditioner would normally do. Eventually, enough warmer room air reaches the Ice Bears intake vents to melt all the ice in the device, leaving it filled with liquid water. When that happens, the buildings air conditioning finally kicks on, and runs until the Ice Bears water supply is frozen again overnight.
The California Public Utilities Commission mandated the storage plan as a way to smooth out the daily highs and lows of power production and consumption. There are times during the day when we are producing more electricity than we need, and other times when demand exceeds what is on the grid. This will help us avoid blackouts without having to build new generation, state assemblywoman Nancy Skinner told the San Jose Mercury News in 2013 when the project was first proposed. Now, electricity produced by power plants running at night when demand is low can be stored and used during the day when demand is much higher. More storage capacity will be especially helpful in encouraging the installation of solar panels and wind turbines, which can provide power only when the sun is out and the breeze is blowing.
Ice Energy estimates that one of its $10,000 units can shift 72 kilowatt-hours of on-peak energy to off-peak hours. Thats enough to keep 72 40-watt bulbs running for just over a day.
So far, Southern California Edison is willing to buy 2,500 Ice Bears for the West Los Angeles Basin region, according to the press release announcing the decision. But this is only contributing to a small portion of Californias 1.3 gigawatt mandate. Well have to wait and see how much less weight the system will have to bear with these units in place.
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12 December 2017