A study on optimal sizing of stand-alone photovoltaic stations

One major application of photovoltaic (PV) power has been in remote areas as isolated small power generation for essential electric power. This paper discusses issues in optimizing the use of such stations and presents a procedure to evaluate different PV schemes considering the stochastic natures of the insolation and the load. The reliability measures in terms of loss of load hours (LOLH), the energy loss and the total cost have been used as the indices for evaluation of different schemes. The insolation and the load demand are modeled as stochastic variables using historical data and experimentation respectively. The operation of various stand-alone schemes are simulated for a specific load. Actual commercially available panel and battery sizes with actual costs have been used in the various configurations studied. The long run expected values of the performance indices for various configurations of the solar station have been measured. Comparative analysis of the results show that higher cost not necessarily translates into better performance. The panel size and the battery size have different impacts on the indices of performance, and a proper balance between the two is necessary to optimize the operation of a stand-alone PV scheme.