Impacts of Storage Upon Solar Plants: General Principles and Seasonal Applications

摘要

In order for central solar electric plants to make a sizable impact on this nation's energy supply, they must be close to and economically competitive with the alternatives. Such plants will have to contend with daily-, seasonal-, and weather-induced variations in solar availability (insolation). Thus, there will generally be a need for storage of solar energy either to achieve reliability or high capacity factors. This study examines the worth and the way in which storage should be utilized in non-grid integrated solar plants. Both the solar/fossil hybrid electric plant and, as a special case, the pure solar plant are considered. The approach taken has been to develop general principles for solar energy storage which are widely applicable and useful, even beyond solar thermal plants. The basic thrust is to explain the rather simple relationships between collector field sizes, storage ratings, and plant output. Where applicable, detailed computer simulation and/or simple analytical tools are used to illuminate storage implementation strategies. These tools are then applied to the specific case of seasonal energy storage using thermochemical processes. In the computer model, hour-by-hour insolation data are used for Albuquerque, NM; Miami, FL; Madison, WI; and New York, NY. The effect of yearly variations is quantified by examining many years of data; and the sensitivity to fossil fuel, heliostat and storage subsystem costs is determined. (ERA citation 06:012206)