Energy Storage System May be the Missing Link between Intermittent DG and Utility Grid
On April 21, 2008, the U.S. Department of Energy announced that it will invest up to $50 million over five years in nine demonstration projects which will show how peak demand can be reduced by up to 15 percent at the distribution feeder grids—the power lines which deliver electricity to consumers. Most of these projects…
On April 21, 2008, the U.S. Department of Energy announced that it will invest up to $50 million over five years in nine demonstration projects which will show how peak demand can be reduced by up to 15 percent at the distribution feeder grids—the power lines which deliver electricity to consumers. Most of these projects incorporate multiple forms of distributed generation, advanced communications, and energy storage.
A Canadian company called VRB Power Systems, has been selected to work on one of these projects—reducing peak power needs at the Santa Rita jail in California. VRB has developed a state-of-the-art energy storage system (called VRB-ESS) that can serve as a buffer between the non-firm, fluctuating supply of intermittent wind and PV generators and the firm requirements of a utility power contract. A stabilized supply means a distributed generator can offer a wider variety of energy “products” to the utility at a higher price. VRB recently published an Executive Summary which describes its energy storage system—a regenerative fuel cell battery which can convert large amounts of electrical energy into chemical energy and vice versa.
The grid applications of this technology include: load leveling and peak shaving; ancillary services to utilities, such as spinning and standby reserves, reactive power, blackstart, and frequency control; electric power arbitrage—allowing power to be bought and stored during low-cost off-peak periods and sold during high-value on-peak periods; relief within grid-constrained load-pockets; deferral of capital investments; and many other services.
Until recently, power storage has not been economically practical. However, the large-scale and high-capacity capabilities of the VRB-ESS system has provided a fundamental shift in thinking about the way power systems can be designed, or modified, and operated. The VRB-ESS technology has been demonstrated at 16 sites around the world and is now in its early commercialization phase.