Ideally, panels on commercial, residential, industrial and agricultural buildings and sites would produce enough electricity to offset some of the work that power plants must do. Peak-load demand comes when a utility must use all of its power plants to supply its customers with the electricity they need when their needs are the greatest, usually in the summer during daylight hours. The responsibility for meeting increasing peak-load demand or being able to fully service consumers is what drives electric companies to build new generating plants. If utilities can't build new plants, if supply can't keep up with demand, customers would have to live with brownouts and blackouts. But, Byrne contends, photovoltaics can reduce peak-load demand more efficiently and with less discomfort and inconvenience to consumers.
Water heaters are a good example.
That saves anywhere from 300 to 700 watts per heater, thus lowering demand when demand is at its highest. But, customers lose normal hot water service until it's time to turn on the heat. What the energy center study will show, Byrne said, is that photovoltaic cells, using the sun to produce electricity, can keep the water sufficiently warm, eliminating the need for the utility to serve the heater during peak-load periods. There would be no need for consumers to suffer hours of lost normal hot water service and no need for the utility to supply electricity to reheat their water. The grant began in October.