Cost Optimization of an Off-Grid Hybrid Renewable Energy System with Battery Storage for Rural Electrification in Pakistan

Renewable energy sources are facing problem of intermittency because of its dependence on climate condition. To overcome this problem, an off-grid micro-grid renewable energy system consist of solar PV, biomass and micro-hydro with small battery bank in HOMER is presented in this paper for rural area electrification in Pakistan. Solar PV and micro-hydro are the primary sources to serve load demand, while biomass and battery provide backup in peak hours. A bi-directional converter is used, when load demand decreases battery bank gets charged from micro-hydro and solar PV. Battery bank will provide electricity to consumers in first priority, when state of charge (SOC) of battery drops biomass will be brought online to serve the peak load and charge the battery. The use of battery bank reduces biomass operation to reduce the system Net Present Cost (NPC) and Levelized Cost of Electricity (LCOE) to make the system economically feasible and reliable. A hybrid model is proposed in this paper in which by reducing biomass generator operation, biomass fuel consumption is decreased as a result system total net present cost is reduced and ultimately cost of electricity is minimized.