Thanks to PV systems and battery storage, millions of households in Europe are already partially self-sufficient.

A German-Swiss research group has calculated the potential for European residential buildings to achieve grid independence with solar-plus-storage solutions. The team aimed to determine whether such homes could abandon the grid completely.

They based their calculations on a database that combined detailed geographic data about European buildings and households with local climate and economic factors. Using advanced techniques to simplify the process on high-performance computers, they designed cost-optimized, self-sustaining energy systems for 4,000 representative single-family homes. These results were then applied to the 41 million single-family homes they analyzed using neural networks.

“Under today’s conditions, 53% of the 41 million buildings are technically capable of powering themselves through the use of local rooftop PV systems alone, independent of external infrastructure, and this share could rise to 75% by 2050 due to improved technologies,” said researcher Russell McKenna. “If we now assume that building owners would be willing to invest up to 50% more than would be necessary for a comparable energy system with a grid connection, then up to two million single-family homes could leave the grid by 2050.”

Energy self-sufficient residential buildings show great potential, particularly in regions with stable weather patterns like Spain and areas with high electricity costs such as Germany. Electrolysis could also be a key component in cost-optimized systems.

“Our results show that a successful, cost-optimal and self-sufficient energy supply system for buildings in Central Europe will consist of photovoltaics for electricity generation as well as a combination of short-term battery storage and a long-term, seasonal hydrogen storage system,” said researcher Jann Weinand.

The key question is whether widespread adoption of fully self-sufficient, off-grid supply systems aligns with an efficient energy system. Single-family homes can contribute significantly to stabilizing a renewable-based energy system through load management, on-demand solar power injection, and provision of balancing services.

The research group was formed by scientists from the Karlsruhe Institute of Technology (KIT) and the Forschungszentrum Jülich GmbH, as well as the Swiss Federal Institute of Technology Zurich (ETH Zurich) and the Paul Scherrer Institute.