Power: Energy on call: A more efficient peaking system would exploit the advantages of energy storage, while conserving capital and resources

The peaks and valleys of demand for electric power vary with the seasons, the days of the week, and even the hours of each day. But the power industry must maintain generation, transmission, and distribution capacity to meet the peak demands, and that means that during off-peak periods, facilities are used below their full or base-load capacity. In fact, the average use of U.S. capital investments in electric power generation is only about 50 percent of their potential full use, while the average use factor for transmission facilities is approximately 35 percent.