Ice can be used to store energy (though the other way we may be tempted to think) just like hot bricks or molten salt. Several Southern California municipal utilities will be implementing ice-based energy storage devices to reduce the air conditioning consumption in government offices and commercial buildings. Over the next two years, they will install 6,000 devices at 1,500 locations, storing around 53 megawatts of energy in total.
The cooling devices, made by Ice Energy, a CO-based company, will make the cheap ice overnight, when the demand and prices of electricity are low. They will use a highly-efficient compressor to freeze 450 gallons of water, which they will use the next day by shutting down the regular air conditioning installation and instead use the stored energy.
The slowly-melting ice blocks will exchange heat with a coolant that will circulate through pipes and go to an evaporator coil, installed in the building’s main air conditioning blower system. The entire process would last about 6 hours (until the ice melts), covering an entire afternoon, while the demand on the grid is at its peak.
On one hand, such storage systems will protect the grid from overloading and lessen the cases of them turning on their backup generators, reducing fuel consumption for the utilities by up to 30%. On the other hand, they will be made cheap enough ($5,000 each) to reduce the individual buildings’ fuel consumption by 90%.
Although the big plans are to install huge energy storage devices in the desert, below rocky mountains, in the form of compressed gas or molten salt, transferring the gigantic cost of such wide projects to individual users would make the entire power storage idea more flexible and implementable on a larger scale, with even higher profits for governments.