This thesis analyses the production of green hydrogen through water electrolysis powered by photovoltaic systems, exploring its role as a vector for long-term energy storage. The proposed system involves the integration of an electrolyser and a fuel cell for the cogeneration of electricity and heat, intended to meet the needs of a farm located in Piedmont. The analysis evolves from a single-user configuration towards a Renewable Energy Community (REC) model, involving three local farms. This transition aims to optimise widespread self-consumption and access to the incentives provided for by the CACER decree, key elements in ensuring the economic sustainability of the investment.