Profitability of Energy Storage for Raising Self-consumption of Solar Power: Analysis of Different Household Types in Germany

Abstract

We study grid-connected residential photovoltaic (PV) systems with direct feed-in or self-consumption of solar power, and with optional energy storage enabling the share of self-consumption to rise. The focus is on different types of households and different locations in Germany. A net present value (NPV) approach is adopted to investigate the economic viability of the different cases. Global solar irradiation data for Germany are used for calculating the hourly performance of a PV system at a particular location. In a sensitivity analysis, the influence of the electricity price and the discount rate are analyzed. Residential PV systems with energy storage are found to be profitable for all household types investigated. Under the prevailing regulatory conditions, the NPV can be maximized for 100% self-consumption and no energy storage. For a profit-maximizing investor, maximum self-consumption combined with active load control is found to be optimal. The results are robust regarding the expected changes in the feed-in tariffs granted.