Cross Linear Solar Concentration System for CSP and CPV

Abstract

The novel concentration system, Cross Linear (CL) system has been newly invented by Tokyo Institute of Technology. From a simulation study on how cosine effect varies with latitude, declination angle, hour angle, and tan μ (the ratio of the receiver height and the distance from mirror position to the receiver position for the receiver/mirror configuration of the CL system), it was found that the cosine factor of CL system increases with an increase in the latitude. The higher cosine factor with around 0.95 in winter months is obtained by CL system even at high latitudes. The CL system can eliminate the end loss and increase the optical efficiency compared to Trough and LFR (Linear Fresnel Reflector system). This seems to solve the problems in the concentration systems of Trough and LFR; the lower concentration efficiency (lower cosine factor) in the winter months. In addition, a higher temperature around 650°C can be obtained with the CL system, due to the high concentration degree of CL solar reflection method. Thus, the CL system can achieve both high concentration temperature and high collection efficiency in both winter and summer seasons, even at high latitudes. Therefore the CL system seems to be the only CSP system suitable for the CSP-sites at high latitudes such as Mongolia (outer and inner), southern areas of Spain and Australia, and northern area of India. Due to the promising CL system, a joint collaboration between Japanese and Indian industries, institutes and universities has been launched to build solar plant based on CL technology. Also, the CL system also seems to be applicable for the CPV, because the coma tic aberration is very small during 9am to 3pm during the sunlight duration.