Sizing an off-grid photovoltaic system (A case study)

Abstract

To meet the creeping electricity demand, the best option is to tap the energy from the Renewable energy sources and from solar in particular for filling the gap between supply and demand. This paper is aimed at the design of an off-grid photovoltaic (PV) systems which is able to fulfil the electrical power demand in the standalone condition. Various components like solar PV panel, inverter, charge controller, batteries are parts of the system design. The estimated load is 31.30 kWh/ day. 8 kW PV array capacity, 46 PV modules, 16 batteries (12V, 200Ah), a voltage regulators (45A, 24V) and an inverter (10kVA, 48V) were used under the study. The design proposed requires wires made of copper with area of cross-section 1.5 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , 22.0 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and 2.5mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> for installation of panel or charge controller, battery or inverter and load connected wires. The estimated cost of the system worked out to be about Rs. 14.0 lakhs. The systems payback period is estimated to be 13.19 years. The insights from the results of the design can be extended to the other solar PV projects of the same kind.