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 are based on the RETScreen library and NASA related location statistics.

London Plan is the London mayor\'s long term plan for tackling different shortcomings of the London city. Tackling climate change is been outlined in one of its policies named Policy 4A.x. Making energy use more efficient, using renewable energy sources and Combined Heat and Power (CHP) are proposed for the challenge. The plan has been out since 2004 for review and many scholars have commented on many aspects of the plan. This paper evaluates the Policy 4A.x since 2004. This paper longitudinally analyses the environmental, financial and social aspects of the policy. Moreover it discusses the financial domain of the plan in more depth.