The Impact of Solar Radiation on the Annual Net Solar to Power Efficiency of a Solar Aided Power Generation Plant with Twelve Possible “Configuration-operation” Combinations

Solar Aided Power Generation (SAPG) has been approved to be an efficient method of using solar thermal energy. In an SAPG plant, the solar thermal energy carried by the heat transfer fluid is integrated into a regenerative Rankine cycle power plant to preheat the feedwater to the boiler. A heat exchanger which is termed as solar preheater facilitate this heat transfer process. The extraction steam which is bled from the turbine to preheat the feedwater is displaced and expended further in steam turbine to generate power. Depending on the arrangement of the solar preheater, an SAPG plant has different configurations, which is termed as solar preheater configurations. When the solar input changes, the flow rates of extraction steam is needed to be adjusted, which is termed as solar preheater operation strategies. The combinations of solar preheater configuration and operation strategies are called “configuration-operation combinations”. Previous studies proposed twelve possible “configuration-operation” combinations [1]. It was found that twelve combinations fall into six different groups in terms of annual net solar thermal to power efficiencies [1]. In present paper, the influence of solar collector area and solar radiation on the annual net solar to power efficiencies of twelve combinations has been evaluated. The SAPG plant is modified from a 300 MW power plant, and only the extraction steam to high pressure/temperature feedwater heaters is assumed to be displaced by the solar thermal energy. In addition, the annual solar radiation in three locations have been used for evaluation. The results indicate that the annual net solar to power efficiencies of twelve combinations are more sensitive to the variation of solar collector area in the location with higher annual solar radiation.