Feasibility of hybrid wind and photovoltaic distributed generation and battery energy storage systems under techno-economic regulation

Abstract

The Brazilian electric energy compensation system (EECS) states that 100% of the energy generated and inserted into the grid should be returned to prosumers as credits to their energy bill. Ongoing regulatory changes propose that compensation should only be provided for the energy cost (43%). From this perspective, with awareness of the complementarity between wind and solar sources, energy storage systems (ESS) applied to hybrid distributed generation (DG) can become attractive. This study aimed to assess the economic feasibility of hybrid DG power plants with battery banks. Stochastic analyses were carried out by varying nine of the variables (nominal power, solar radiation, wind speed, electricity demand, energy tariffs, discount rate, battery bank investment, and solar and wind installation costs) in three types of hybrid power plants (micro, mini, and small). All scenarios presented a high probability of viability. The main conclusions are as follows. The complementarity of the sources yields benefits to the system: batteries have a high investment cost, which require incentives for their insertion in the DG as a decrease in battery cost or a specific subsidy. The regulatory framework should consider the possibility of payout for the benefits provided by the use of an ESS for DG, i.e., energy storage is directly related to the smart grid concept.