Smart shopping centers, controlled emission: rooftop PV power generation for a clean metropolitan city Dhaka, Bangladesh

Abstract

Dhaka, one of the fastest growing cities in the world has around 500 shopping centres, which use unstable electricity supply from the national grid. A medium size shopping centre having 50 shops consumes about 320kWh every day during the daytime business hours between 8am to 5pm. This study proposes a sustainable alternative to replace fossil fuel based electricity consumptions by using rooftop solar panels as renewable energy source. A standard daily load demand estimated by surveying twenty shopping centres at different locations in Dhaka city and the optimal rooftop PV power system designed and financial analysis carried out using the HOMER software. The proposed grid tied 110 kW PV system with 30% capital subsidy, 50% soft loan and 20% investor equity can supply electricity at a cost of USD 0.0382/kWh. The rooftop system consisting 180kW generic flat plate PV and 60kW converter produces 262,000kWh/yr. Because of the complex demand pattern around 22,000kWh electricity are to be purchased from the grid every year and 75,000kWh can be sold back to the grid. The initial subsidized cost for the PV power generation system is USD 133,500 and project net present cost is USD 95,174. While saving substantial amount on the electricity bill and reducing pressure on the country’s limited generation capacity, the 500 installed rooftop PV systems can save 60,000 metric tons of carbon dioxide into the atmosphere. The same model of smart shopping centres can be applied in all the urban areas of the country.