Economic evaluation of solar hybrid DC grid for petrol pump stations

Present day India´s power scenario is in a precarious situation with power outages for around 2 hours a day in urban areas and 8-10 hours a day in rural areas. Petrol pump stations are one such sector, which is heavily affected due to the significant gap between electricity demand and supply. In most of the cases, diesel generator (DG) set is used as power backup source which decreases profit margins because of higher running cost. Switching to solar hybrid power system with battery backup would free them from adverse effects of load shedding, expensive diesel bills and toxic fumes. However, higher initial investment on solar balance of systems (BOS) like battery, solar panels and associated electronics is not in favor for its wide adoption. In this paper, concept of storage integrated DC grid (SID) along with system design is proposed for a typical petrol pump station. Financial feasibility study is performed for the proposed system with respect to DG set system and conventional solar power system. Economic analysis in terms of total cost of ownership, cumulative savings over years is presented. It is shown that though the initial investment of solar system is high, the total cost of ownership is much less than DG set if considered for period of 3 years or more with significant cumulative savings.