Photovoltaic energy systems with battery storage for residential areas: an economic analysis

The global energy market is characterized by the strong growth of photovoltaic (PV) energy. This renewable source contributes to sustainable development and is a strategic player in the electricity market. The profitability of PV systems is determined by incentive tariffs in developing markets and by the share of self-consumption in developed markets. This paper aims to evaluate (i) the profitability of PV systems in the residential sector without subsidies and (ii) the profitability of energy storage in a mature market (Italy). In this way, it is possible to define the economic results of integrated PV-battery systems, and the indicator used is the Net Present Value. Furthermore, a sensitivity analysis is conducted on the critical variables. The mathematical model proposed in this paper defines the break-even point of the increase of self-consumption at which residential PV battery systems become economically viable in a mature market. Energy storage systems are useful only when the relationship between supply and demand permits them to induce a significant increase of energy self-consumption.