Author : Monika G. Barade and Anindita Roy

A hybrid system based on photovoltaic array integrated with diesel generator and battery is considered an effective option to electrify remote and isolated areas where transmission of the grid is not possible. In the design of a photovoltaic array-diesel generator-battery hybrid system, selection of a suitable size, blending of the photovoltaic array, diesel generator and battery storage with the optimum mix of energy delivered by diesel generator, battery and obtainable from photovoltaic is an important issue in such hybrid systems. This paper presents the development and application of a simple spreadsheet modeling software based on time series simulation methodology. Results show that the optimal configuration of an autonomous system is 50% of the annual energy demand is met by diesel generator, while the remaining 50% is delivered by the photovoltaic integrated with a battery and minimum cost of energy will be 13.1 Rs/kWh (assuming diesel fuel price of 60 Rs/L). Photovoltaic array – diesel generator system integrated with battery system has been analyzed for energy demand through sensitivity analysis using life cycle cost calculated and system sizing under resource uncertainty with the help of probabilistic approach. The investigation also examines the effect of different diesel generator loading on optimum photovoltaic penetration and cost of energy. System sizing and optimization to minimize the operational hours of diesel generator with an increase in photovoltaic capacity with the help of battery storage.

Keywords: Photovoltaic array – diesel generator – battery hybrid system optimal sizing, Photovoltaic penetration, Sensitivity analysis, Uncertainty of resource.