Greenhouse gas balance of solar parks built on peatlands in Germany

Drained peatlands are responsible for around 4% of anthropogenic GHG-emissions. To trigger the necessary large-scale rewetting, solar parks built on rewetted peatlands in Germany have been eligible for a feed-in tariff since 2023. Building a solar park on a rewetted peatland requires some technical alterations, particularly of the mounting structure. Building a regular solar park on a drained peatland might thus obstruct its rewetting, allowing for the peatlands' GHG-emissions to be allocated to the solar park. This study finds that the GHG-emissions of solar parks built on drained peatlands are between 76 and 199 g CO₂-eq kWh^-1. The GHG-emissions from the drained peatlands contribute between 38 and 76% to these total emissions. The GHG-balances are between -95 and 27 g CO₂-eq kWh^-1. The positive GHG-balances highlight that ensuring that solar parks cannot be built on drained peatland anymore is crucial. Solar parks on rewetted peatlands require careful planning as water table regulations and implementation timelines might not be sufficiently strict in Germany.