Background: The German energy transition strategy calls for reform of the German energy sector. Against this background, the Germany Renewable Energy Sources Act, or EEG, was issued in 2000 and is widely regarded as a successful legislation for promoting bioenergy development, as more than 9000 biogas plants were built in Germany until 2017. However, the impact from different EEG periods on regional biogas plants’ development and the long-term influence to regional landscape change are rarely simultaneously studied.
Methods: This study aimed to quantitatively analyse the impact of the EEG on promotion the biogas plant development in central Germany (CG) by using the event study econometric technique. A GIS-based spatial analysis was further conducted to provide insight into the changes of the agricultural landscape, which was resulted from the development of biogas plants during the EEG from 2000 to 2014.
Results: One of the main findings was that the EEGs had time-varying effects on motivating biogas plants construction and selecting the plants size. The comparison between different EEG emendations suggested that the EEG 2009 was the most successful one in market implementation. Besides, the adoption of the biogas plant in CG was mainly driven by the farmer’s financial incentive and taken as an investment to secure the farming business. At the landscape scale, the expansion of silage maize was remarkable in CG from 2000 to 2014. The silage maize was intensively cultivated in the regions with high biogas plant installed capacity. Since EEG 2009, the regional livestock number increased rapidly, which was also associated with increasing pasture land area in CG. This phenomenon suggested a promising regional animal farming and its potential of manure as biogas feedstock.
Conclusions: These findings imply that the policy makers should take the EEG 2009 emendation as reference to promote the marketing of future new renewable energy technologies and cautions should be paid on the potential land conflicts of agricultural-based bioenergy development.