PV parks as biotopes

13 November 2025

To some people, solar parks may seem like blots on the landscape. But as well as helping the climate, they can also benefit nature conservation, providing a home for endangered species such as skylarks and wheatears. However, not every ground-mounted PV system is automatically a biodiversity booster. What conditions need to be met for solar parks to promote biodiversity?

Solar panels stretch into the distance for as far as the eye can see. The Gottesgabe solar park near Neuhardenberg covers an area the size of 190 football pitches, making it one of the largest and most powerful installations in Germany. Around 44,000 households are supplied with green electricity from here, and surplus energy is diverted into large battery storage systems for operational needs and the nighttime hours.

Since Gottesgabe went into operation in 2022, however, a lot has happened, with much movement around and among the 350,000 solar modules. Tim Peschel has discovered 68 different plant species on the site. The biologist examined the solar park in 2024 as part of a field study and came across an abundance of animal life in the process: various species of grasshoppers, including the endangered blue-winged sand grasshopper, chirp under cover of the flowers which also attract wild bees and butterflies. Because no pesticides are used in solar parks, insects can thrive better here – to the delight of reptiles and birds such as the skylark. The latter is on the Red List in Brandenburg and has settled in the Gottesgabe solar park. This in turn makes the site attractive for kestrels and buzzards, which regularly fly into the park, as Mr. Peschel has found.

Gottesgabe is one of a total of 31 solar parks that Mr. Peschel and a colleague examined as part of the field study. According to the German Association of the New Energy Industry, which commissioned the study, this is the world’s most comprehensive study of biodiversity in solar parks on former agricultural land, where most new ground-mounted systems are being built in Germany today. The results are impressive: the biologists have detected 385 plant species, 36 species of butterflies and 30 species of grasshoppers. In ponds and wetlands around the panels, 13 dragonfly and eight amphibian species are happily thriving, including the highly endangered yellow-bellied toad. The inhabitants of the solar parks also include 32 species of birds, and a further 63 bird and 13 bat species head for the installation in search of food.

“Ground-mounted PV systems offer a mosaic of new, clearly suitable habitats for many species in the structurally poor agricultural landscape,” says Mr. Peschel, quoting the study’s central finding. Solar parks offer real added value for biodiversity, according to the biologist – as long as they are well planned and properly maintained.

To ensure that diverse flora and fauna can develop around and under the panels, they must not be installed too low to the ground or too close together. This is because many species need enough light to thrive. This is why experts such as Elke Hietel from Bingen’s University of Applied Sciences recommend a minimum sunlit area of 3.5 metres between the rows of modules. “Overall, no more than 40 percent of the total area of biodiversity solar parks should be covered with modules,” says the professor of landscape conservation, landscape and urban planning, who has worked with her team to draft a policy for biodiversity-promoting solar parks for Rhineland-Palatinate’s Ministry of the Environment.

The use of mixed seeds of native wildflowers and grasses lays a good foundation for a species-rich flora. Operators can also promote biodiversity by planting hedges and trees at the edge of the site and installing small bodies of water or other biotopes. While piles of deadwood, for example, are attractive to many insects, rare bird species such as the wheatear will find places for their nests on piles of stones. Since solar farms are fenced off, large plants also need corridors to allow the passage of deer.

Whether all these measures achieve the desired effect depends to a critical extent on how well the solar park is maintained. “Grazing by sheep is basically the best solution, as it is less tough on the vegetation,” says Ms. Hietel. These ovine stewards of the landscape also serve as taxis for seeds that get caught in their wool. They attract insects, and their hooves also create gaps in the soil from which less assertive plant species benefit, as do wild bees.

If the solar park has to be mowed, this should be done using insect-friendly beam mowers and, if possible, section by section. This approach will always leave areas of flower meadow intact as shelter for the animal life.

Ms. Hietel stresses the importance of removing the cut grass after mowing: “All too often, however, it is used on site as mulch, which enriches the soil with nutrients.” The problem here is that nutrient-rich soils favour the spread of grasses, displacing other plant species. It is therefore important to “starve” the former agricultural land, i.e. to reduce its nutrient content. “The poorer the soil, the more species-rich the flora,” Ms. Hietel states. “This emaciation of the soil and sectional mowing require a well-thought-out maintenance concept, which should be developed by experts right from the planning phase.”

According to Ms. Hietel, environmental support is also essential after the plant is commissioned. In the first five to ten years, regular monitoring is needed to check whether the biodiversity is developing as desired on the sites to allow adjustments to be made if necessary.

What is implemented and the extent of any measures still depends on the goodwill of the project planners. Compensatory measures are imposed on all solar parks in the course of the approval procedure to compensate for the encroachment on the natural environment associated with their construction. It was in this context that hedges and trees were planted around the plant in the Gottesgabe solar park and biotopes created. But such compensatory measures are primarily aimed at maintaining the status quo on the ground. Guidelines for biodiversity-promoting solar parks, as published by Rhineland-Palatinate and other states, go well beyond this and are intended to provide guidance for licensing authorities and planners – but they are not binding.

Some operators voluntarily go beyond the mandatory requirements. In Upper Lusatia, for example, green electricity supplier Naturstrom is working with Germany’s Nature And Biodiversity Conservation Union (NABU) to further promote biodiversity in the existing Nochten solar park. The German Solar Industry Association has also recognised the importance of species protection and has teamed up with NABU to develop standards to support member companies in their planning of nature-friendly plants.

For a long time, there were no binding requirements at the federal level to actively promote biodiversity in solar parks. The first step in this direction was the amendment to the Renewable Energy Sources Act, which came into force in 2024. The five requirements set out in what is known as Solar Package I include passability for wild animals, the creation of biotopes and a biodiversity-promoting maintenance concept. “However, companies only have to meet three of the five requirements, meaning that they can limit themselves to the ones that can be implemented without too much effort,” says Ms. Hietel. Not only that, but the requirements only apply to subsidised systems – and in 2024, almost a third of the newly installed solar park capacity was installed without subsidies.

Nature conservation organizations such as NABU are therefore calling for binding and comprehensive minimum requirements for all PV parks in Germany. Ms. Hietel’s recommendations include awarding particularly exemplary plants the status of “Biodiversity Solar Parks”, making them eligible for higher funding. “The biodiversity crisis we’re in today is just as existential a threat to humanity as climate change,” says the expert. “So, achieving the best possible combination of climate and environmental protection is a great opportunity that we should definitely seize.”