Utility Load Management and Solar Energy. Study Background and Preliminary Market Potential Analysis

摘要

The large-scale use of electrically assisted solar heating and hot water (solar/electric HHW) systems can have a substantial effect on electric utilities. Under some conditions, peak loads may be increased causing electricity generation costs to rise. However, with appropriate control and thermal storage equipment tied to the HHW system, the timing of the delivery of electricity to the HHW system can be controlled so that it is accomplished during those times of the day when utility supply costs are lowest. In this study various load management schemes for these applications are being investigated to determine their effect on the cost of generating the back-up electric power and on the cost of the required control and storage system. Solar/electric HHW systems are compared to electric-only systems for several utilities and several HHW system designs. The issues underlying the study, the methods of investigation, and the results of the first phase of the study are described. In this phase a preliminary analysis of the maximum market potential for night-time precharge electric-only hot water systems in either utilities was conducted. This analysis indicated that if about 20 to 40 percent of the residential customers used these appliances in a load managed mode, the 10 PM--8 AM valley in the utility load curve would be filled. For combined electric heating and hot water, the corresponding fraction is 6 to 12 percent. It is estimated that in each case, roughly twice the number of residential customers could be accommodated in the valley if solar/electric systems were used instead. (ERA citation 04:025961)