The current energy crisis has shifted human efforts towards looking for and using renewable energy sources. One of the well-known of these, is the solar energy. The two well-known harvesting systems are PV and solar thermals. This paper tries to reflect the Photovoltaic systems in general in first instant. Furthermore it considers the efficiency analysis of the PVs by means of RETScreen 4 software. The case study chosen for this paper is University of East London located in London, England. The analysis is based on the RETScreen library and NASA related location statistics
