Solar Assisted Power Systems

Except for hydroelectric power, solar electric generation has not been widely used in the past to assist power system generation because of its relatively high cost. This situation has now started to change with the advent of the energy crisis as exemplified by decreasing natural gas supplies and increasing fossil fuel prices. One possible response to this situation which appears to have a relatively good chance for economic success is the utilization of wind and solar thermal energy for space and water heating loads served by natural gas or electric power. Unfortunately, a large portion of the energy collected in a typical solar heating system is lost because the received solar energy is variable and, in most cases, is not well correlated with collection site loads. This paper examines the feasibility of using the excess energy available from solar heating systems for electric power production so that power system peaking capacity and total fossil fuel consumption can be reduced. As solar electric generation becomes larger, energy storage systems will be needed to assure power system stability and reliability. At the solar collection site, thermal energy and chemical storage units in battery form are preferred. For large central energy storage facilities pumped hydro, compressed air, liquid ammonia, storage batteries, and liquid hydrogen systems are possible choices. The liquid ammonia storage system is considered the best overall choice when pumped hydro or compressed air are not feasible