About 24 municipal buildings in Southern California are about to help ease the strain on the grid created by the peak need for air conditioning on hot California afternoons. Over the next few weeks, a consortium of municipal utilities in California will begin retrofitting government offices and commercial properties with systems that use ice made at night using cheap surplus wind power to replace air-conditioning that they would have required during the afternoon.
The first cheap energy storage cooling units housed at distributed sites on the buildings will be networked, providing utilities with a resource that can be dispatched as needed to help manage demand on the grid.
The 53 MW distributed energy storage project will demonstrate savings, such that if put into general use, would reduce fuel consumption by the nation’s utilities by up to 30%, using efficiency “negawatts”, and by individual building owners by up to 90%.
The units are made by Colorado-based Ice Energy, a recipient of the DOE 30% tax credits for investments in new, expanded or re-equipped clean energy manufacturing projects, for bringing much-needed jobs to upstate New York where it will scale up its manufacturing operations.
Over the next two years, the 11 small participating utilities will install 6,000 of the devices at a total of 1,500 locations, providing 53 megawatts of energy storage to relieve strain on the grid, and coordinated by the Southern California Public Power Authority.
The units make cheap ice overnight, when demand for electricity is low, using a high-efficiency compressor to freeze 450 gallons of water. In the middle of the day, the device shuts off the regular air conditioner for the peak afternoon hours and instead pipes a stream of coolant from the slowly melting block of ice to an evaporator coil installed within the building’s heating, ventilation, and air-conditioning blower system until the entire ice block has melted – which should be sized to take about 6 hours – to cover for the peak afternoon load on the grid.
The utility also saves energy at other points in the grid–for example, cooler power lines at night transmit electricity more efficiently. Although ice storage systems have been used in large commercial buildings – the Bank of America Building in Manhattan is a LEED-Certified example – these tend to be expensive custom-built designs. This project uses mass-produced scalable modular units.
At $5,000 each, these will be within the means of commercial property-owners, and would bring up to 90% reduction in individual building’s fuel use. For California, the implications are huge. Large-scale implementation of Ice Energy’s (already tried and tested) small modular units as energy storage for the grid would put off the need to build new power plants. And not just in the SCCPA utility district.