Repowering biogas plants in Baden-Württemberg

The project analyzed the possibilities for repowering biogas plants in Baden-Württemberg and regarded the economic and ecological conditions and challenges not only at plant level but also at the energy system level. Furthermore, the effects on the bioeconomy and selected performance indicators for the existing plants in Baden-Württemberg were determined.

Repowering the energy economy describes means of increasing efficiency or output of existing power plants by replacing components. In terms of biogas plants these changes can occur in various parts of the process chain. They can be of biological, technical, or conceptual origin

In the project, various measures for the repowering of biogas plants were identified and analyzed in order to address different motives such as legal requirements, the impact of the measures on the existing plant concept and to distinguish repowering from other technical measures. The following categories and measures groups were formed:

A new analysis model was developed to determine the holistic effects of repowering. It carries out integrative mass, energy and greenhouse gas balances for all existing plants over the considered period and calculates key performance indicators such as the leveled costs of electricity. The model was used to examine various measures and scenarios for the development of the plants in Baden-Württemberg. The focus in these scenarios was put on the changed framework conditions and requirements on the energy system in form of flexibility. Important parameters such as the technical progress of CHP units were also taken into account.

The scenarios show that the number of biogas plants in Baden-Württemberg will be significantly reduced after the expiration of the first EEG period. If a flexibility strategy and a continued operation on the basis of the EEG bidding process are successfully carried out, the available capacity can be maintained beyond 2020.