Economical comparison between a stand-alone configuration of a PV system with energy storage and a grid-connected one.

Greenhouse gas emission reduction and the control of excessive use of fossil fuels currently represent one of the main objectives of European energy policy, especially in order to limit dangerous climate changes. In particular, the building sector is today recognized among the main causes of significant rates of energy consumption and therefore it needs special attention in order to improve energy performance, mainly by increasing energy efficiency and use of renewable sources. Currently, the widespread use of renewable sources is limited by their intrinsic discontinuities, which can be overcome using energy storage. In this framework, in the paper the economic feasibility of a stand-alone photovoltaic plant along with a battery storage system is analyzed. The cost of the whole system is then compared with that of a grid-connected configuration, evaluating the distance from the grid which makes more convenient the use of each of the two configurations.