You pay the most for power during weekday hours and the least on weekends and overnight. Puget Sound Energy is about to start one this summer in Western Washington. In California, that could reduce energy costs by 12 percent over the summer. So far, however, these programs haven't persuaded many people to run their washing machines at night. The utility varies your price per kilowatt-hour during the day, as its own prices change.
Many businesses already pay on real time.
How consumers like real-time pricing remains to be seen. Georgia Power tried it 12 years ago and dropped it. But Gulf Power rolled out newer technology last year and thinks it has a hit. She says that customers are saving 15 percent, which more than covers their participation cost. Consumer and environmental groups generally haven't supported market-based pricing for homes.