Researchers in Germany have found that solar panels on rewetted peatland provide a unique habitat for bird species along with generating green energy and potentially locking up carbon. The findings are published in the British Ecological Society journal, Ecological Solutions and Evidence.
Installing solar panels on rewetted peatlands is a new type of land use, providing a way to generate green energy and reduce greenhouse gas emissions. Now, research from the University of Greifswald has found that this novel land use may also benefit nature.
In the study, researchers compared bird diversity at a solar park on a rewetted peatland site in Northern Germany. The site was surrounded by intensively farmed and drained peatland. They found the solar park was home to several threatened bird species and contained an unusual mix of species associated with agricultural, wetland and even woodland ecosystems.
Hanna Rae Martens, a peatland ecologist at the University of Greifswald and lead author of the study, said: "The presence of wetland species like reed bunting and the endangered meadow pipit shows that the solar park is truly re-wetted and has peatland species returning.
"But we also recorded species like Eurasian tree sparrow and tree pipit which are not typically found in peatlands. They all appear to use the structure of the solar panels. When I'm out on site, I see a lot of meadow pipits sitting on the panels, flying off to catch insects and then flying back to their perch."
80% of peatlands in the UK are degraded. In Germany this number is even higher at 95%, primarily due to drainage and agriculture use. Globally, drained peatlands are responsible for 5% of greenhouse gas emissions.
Rewetting drained peatlands could slash these emissions and restore biodiversity, but there are two key problems. The first is that once rewetted, the majority of commonly grown crops can't be produced on this land. The second is that it can take several decades to restore deeply degraded peatlands to a healthy, functioning state.
The study site is one of the first to build solar panels on rewetted peatlands. Under the scheme by the German Government, landowners are paid to install solar panels and rewet the site, providing an alternative source of income. The findings from the study suggest that, at least in the short term, this could also be boosting biodiversity.
"Where the alternative is a drained, intensively managed peatland, our research demonstrates that solar panels on rewetted peatland might benefit bird diversity." said Hanna Rae Martens. "But we're not suggesting that we should be turning all peatlands in Germany, the UK, or any other country into solar parks. Healthy peatlands or those with high restoration potential should be avoided. Solar parks are just one possible tool to support peatland rewetting."
In the study, which took place between March and October 2024, the researchers used audio recorders and machine learning to compare bird diversity in a solar panel site on rewetted peatland with nearby drained peatland sites used to grow grass for livestock feed.
The researchers caution that their study presents just one case study for this novel land use type. Hanna Rae Martens said: "To date, there are approximately five rewetted peatland solar park sites in existence. More research is needed to draw robust conclusions as to whether these findings occur in other sites as well, and which factors are contributing to the species composition."
The researchers are now looking to expand their research to include more sites, monitor other species like bats and insects, and identify which elements of the solar park structures can be optimised for biodiversity.
