Abstract
<title>Abstract</title> <p>Europe’s transition to a low-carbon energy system is reshaping household electricity generation, consumption, and storage. Residential batteries can increase rooftop photovoltaic self-consumption, support energy autonomy, and provide grid benefits when operated in a coordinated manner. This study applies the Clean Energy Adoption in the Residential Sector (CLEARS EU) model to project residential battery diffusion under four electricity tariff designs of increasing complexity and to assess their grid-level impacts across 25 European countries. The model combines net present value calculations with Bass diffusion dynamics to capture financial and behavioural drivers of adoption. Results show that tariff design strongly affects battery profitability and diffusion. Under self-consumption, investment returns remain weak in some large potential markets, limiting residential battery capacity to 356–424 GWh by 2050. More advanced tariff designs that allow grid interaction and benefit from rapid cost reductions raise projected capacity above 530 GWh. Battery operation also determines system impacts: annual discharge rises from about 65 TWh under self-consumption to 168 TWh with peak-hour feed-in, while coordinated flexibility can reduce peak-load pressures. Estimated emissions savings range from 6.1 to 8.6 Mt CO₂-eq annually. The findings underline the importance of advanced tariff design for integrating distributed storage and supporting power-sector decarbonisation.</p>