Proposal of a Solar Coal Power Plant on Off Design Operation

Abstract

In a solar hybrid system, the intermittent solar radiation seriously effects the solartoelectricity conversion. In this paper, the energylevel mechanism between the concentrated solar heat and the thermal cycle was discussed. The system analysis was taken on a 200 MW coalfired power plant hybridized with solar heat at approximately 300 آ°C, where the middletemperature solar thermal energy was used to preheat the feed water before entering the boiler. With changing solar radiation in typical days, the solar share, the work output and the net solartoelectricity efficiency of this solar hybrid system were evaluated. The net solartoelectricity efficiency would be increased by 3–7% points compared to that in a solaronly power plant. An offdesign parallel configuration of this hybrid system was proposed, achieving the net annual solartoelectricity efficiency of 18%. It would expected to be an attractive approach to develop the scaleup midtemperature solar thermal power technology in the short and midterm.