In Germany, there are various legal configurations in which renewable energy communities can jointly generate, store, and/or consume electricity from renewable energy sources. These include, e.g., tenant electricity models (Section 42a EnWG), collective building supply (Section 42b EnWG), and – following recent legislative implementation – energy sharing (Section 42c EnWG). With the introduction of energy sharing, different groups of actors – such as private individuals, municipalities, as well as small and medium-sized enterprises – can for the first time jointly generate energy from renewable installations and use it across multiple locations. 

For the successful establishment of energy communities and viable business models, the level of self-consumption and the degree of self-sufficiency play a central role, as they largely determine economic viability and attractiveness for potential participants. At the same time, grid exchange is a key indicator of the additional relief or burden on electricity grids that may result from different designs of energy communities. Against this background, this study examines how self-consumption, self-sufficiency, and grid exchange change depending on different configurations of actors, generation technologies, and generation-to-consumption ratios. 

The results show that a high diversity of generation and load profiles is advantageous in nearly all scenarios considered, as it increases both self-consumption and self-sufficiency while simultaneously reducing grid exchange. The specific configuration has a substantial impact on self-consumption, self-sufficiency, and the extent of grid exchange. Especially in the case of electricity generation based purely on wind power, the share of self-consumption varies significantly – by up to 13 percentage points depending on the configuration.  

The study provides a broad set of concrete values for a wide range of configurations. A summary of the key data is provided in the presentation.