Commercial Successes in Power Storage: Advances in Power Electronics and Battery Application Yield New Opportunities

摘要

LARGE-CAPACITY ELECTRICITY STORAGE SYSTEMS ARE IN DAILY USE around the world, helping to stabilize the electricity delivery infrastructure and minimize the cost of meeting peak-load requirements. Water, as a storage medium, is in its simplest form in a lake behind a dam. By adding sophisticated pumping systems, water from a lake or river can be transferred to another lake (usually man-made) at the top of a hill. The motor-driven turbines for pumping the water uphill can be reversed and become electrical generators when the water flows back down. These pumped-hydro systems typically store the equivalent of hundreds of megawatt-hours of electrical energy and, because of their large power and storage capacities, are relatively inexpensive on a cost-per-kilowatthour basis. These systems typically operate on a diurnal basis: charging with inexpensive utility energy at night and discharging during periods of peak load demand.