In the frame of the StoRES Interreg Mediterranean project, a tool was developed to help private consumers and professionals calculate the optimal size for photovoltaics coupled with a storage system. The aim of the project was to increase the integration of renewable energy in islands and rural municipalities, starting in a few Mediterranean selected countries (Cyprus, France, Greece, Italy, Portugal, Slovenia and Spain).
The free interactive online tool performs an optimisation of the solar installation and battery size. The required inputs include except for the PV and battery size range, the electricity consumption, the location or solar irradiation, technical parameters, financial parameters, energy policies and electricity costs. Pre-set values are available for most parameters, and when applicable tailored to the selected 7 countries of the project. The tool performs a financial analysis for 20 years, offering as a result the optimal system size, the net present value, internal rate of return on the investment and the simple payback period. The results can be exported after the analysis.
The optimisation tool is accompanied by a manual on the same web page, where instructions are provided for all the steps. Furthermore, the page links to a scientific publication whose method is used for part of the calculations, though the exact assumptions are not mentioned. The tool can be useful for energy communities aiming for a first estimation of the optimal size of small-scale PV systems with batteries for auto-consumption.