Wind turbines and wildlife protection: current developments in the Solothurn Jura (2026)

The debate around wind turbines in Switzerland remains topical: while one project in the Solothurn Jura has been withdrawn, another received final approval — both in May 2026.

Wild beim Wild editorial team — 26 May 2026

Primeo Energie AG has withdrawn its wind energy project on the Käsel (Meltingerberg) in the municipalities of Meltingen and Erschwil.

The project envisaged six wind turbines over 200 metres tall and was intended to supply electricity to 4,500 to 7,000 households. At the end of 2025, the project was suspended due to a "lack of acceptance in Meltingen". The Erschwil municipal council confirmed in May 2026 that Primeo Energie would "not currently pursue" the project, as without sites in Meltingen the cantonal requirement of at least three turbines could not be met.

From a wildlife ecology perspective, this withdrawal is significant: the Meltingerberg lies in an exposed, highly visible location. Wind turbines in such mountain sites pose particular risks to birds of prey and migratory birds, which use thermal updrafts and may thereby enter the danger zone of the rotors.

Grenchenberg wind farm approved despite bird protection concerns

In contrast, the Grenchenberg wind farm received final approval on 13 May 2026. The Solothurn Administrative Court dismissed the appeals brought by Helvetia Nostra — a decision which, thanks to the national parliament's "Windexpress", cannot be referred to the Federal Supreme Court. The original project with six wind turbines was reduced by the Federal Supreme Court in 2021 to four turbines in order to protect birds. The four approved wind turbines are expected to achieve an annual output of around 30 gigawatt-hours and supply about 7,000 households.

BirdLife Switzerland and the VVS/BirdLife Solothurn consider the planned wind farm not eligible for approval owing to the impairment of nature and landscape. It is notable that the bird protection associations did not lodge an appeal against the project amendments with the Administrative Court, whereas Helvetia Nostra did.

Wind-power-sensitive species in Switzerland

According to current knowledge, 46 breeding bird species and 2 further visiting bird species in Switzerland must be classified as sensitive to wind power, while during migration all migrating species are considered at risk of collision. The Swiss Ornithological Institute criticises the fact that official national requirements regarding environmental impact assessments in the field of wind energy use do not yet exist, which leads to widely varying quality of such environmental impact assessments depending on the canton.

There is no general tendency for birds to become "accustomed" to wind turbines in the years following their construction. This refutes a frequent argument made by wind power proponents.

Disturbance effects and minimum distances

New studies show detailed minimum distances that various species maintain:

For geese, a disturbance effect of at least 500 metres can be assumed
Geese, swans and waders avoid the vicinity of wind turbines and may thereby lose valuable resting areas
Wild animals keep a distance of 150 m from wind turbines, and important game trails are no longer used

Impact on mammals: massive gaps in knowledge

To date there are only a small number of publications on the influence of wind turbines in forests on mammals, and the results so far are not conclusive and in some cases even contradictory. Observations in Scandinavia (reindeer), Austria (red deer) and Portugal (wolves) point to massive impairments.

In Switzerland, an environmental impact assessment is only required from an installed capacity of 5 MW — which currently applies to only two wind farms. It is therefore unclear what influence small and medium-sized wind turbines have on local and large-scale fauna. Even wildlife corridors of national importance or wildlife sanctuary zones are not listed under the relevant biotope or landscape inventories.