Challenges and Lessons in Residential Energy Storage Projects

Photovoltaic (PV) energy use as distributed generation (DG) has steadily increased worldwide. PV installations on buildings, whether integrated (BIPV) or applied (BAPV), are becoming more common in the built environment and are now a part of people's everyday lives. The exploration of the complementarity between PV systems and battery energy storage systems (BESS) has been propelled by the interest in renewable energy and the continuous rise in utility energy tariffs. This complementarity offers consumers advantages regarding energy dispatch control, potential savings through various tariff structures, and, in some cases, the ability to provide power even when the utility grid is unavailable (off-grid or isolated systems). Although regulatory norms for DG systems in Brazil have been in place since 2012, undergoing revisions in 2015 and 2022, none of these regulations anticipated the installation of BESS behind the meter, within residences. Studies conducted in Brazil, supported by research and development (R&D) projects of the National Electric Energy Agency (ANEEL), have produced interesting findings on the economic, financial, and energy impacts of installing BESS in the national electrical system for small, medium, and large-scale systems. Implementing such systems is still in its early stages in Brazil, and various regulatory, technical, and public awareness barriers are facing it. This study presents the challenges and lessons learned in implementing BESS in real residences in southern Brazil equipped with PV systems. Additionally, it includes case studies from around the world and an exploration of how leading countries are addressing BESS public policies in PV and BESS installations.