Improving the match between the daily solar insolation peak and electrical peak demand

Abstract

Within the next decade photovoltaic solar systems will be used more extensively for generating electricity. The value of that electricity, and the system is directly related to the degree to which its availability coincides with the customers' peak demand. For most utilities and other grid-connected users the peak demand is in the afternoon while peak solar insolation occurs at noon. This paper describes a method of attaining coincidence of the energy collected with the demand for energy. The approach used is to vary the azimuth angle of the collector panel, then determine the corresponding time shift in the peak collection point along with the total energy collected. Results show a 60° shift in azimuth has a corresponding time shift of 1 hr and 40 min in the summer with a small gain in total energy collected. However, the winter time shift is only 1 hr, 20 min and the loss of total energy is 28 per cent. A significant improvement is made to match the demand peak by varying the azimuth angle of the solar collector with a total energy loss that may be acceptable for many users. The results presented here can be used to maximize the value of the photovoltaic systems to specific utilities and other grid-connected users.