French renewable energy company Compagnie Nationale du Rhône (CNR) operates a number of large solar power plants in the Rhône Valley region of France. In 2023, the CNR also hosted a research project by Barré et al. from the University of Luxembourg, during which it was found that solar panel installations had an unexpected effect on bat behavior.
Some conservationists use GPS technology to save the environment by tracking marked wildlife, but Kévin Barré and his team observed the bats in this study via acoustic monitoring with a microphone array. They recorded 15,273 three-dimensional positions of the bats, which allowed them to determine that the majority of bats flew up to 44% faster and 33% straighter in response to the solar panels. This increase in rapid flight directly translated into a reduction of up to 39% in bat feeding behavior in the Rhône Valley test area.
According to a research paper by PA Flemings of Murdoch University in Australia (via Science Direct), solar panels act as “acoustic mirrors” for animals dependent on echolocation, similar to bodies of water. Assuming that bats mistake solar power plants for large lakes, that would explain why they treat them as places where they can fly quickly over rather than stopping and feeding. Additionally, the BBC reports that solar farms have contributed to a decline in the population of bats, birds and insects in the UK. It’s a vicious cycle: fewer insects means less food for insect-eating bats, which in turn further harms the bat population.
Are solar panels worth their consequences against wildlife?
The Global Solar Council says solar energy brings significant benefits to the power grid and reduces the overall cost of electricity. There are also documented cases of solar panels directly contributing to the environment; China’s largest solar farm creates fertile soil in the desert, to name just one example. But are these benefits enough to outweigh the potential harm to animals living in these environments? Is there anything that can be done to mitigate the damage to local wildlife?
The answer likely lies in being cautious about how and where governments allow companies to install their solar farms. CNR solar power plants in France may have caused unexpected effects on bat behavior, but a 2025 study of an eco-voltaic solar power development in the Midwestern United States showed that weekly bat activity near eco-voltaic sites increased by about 50% during the monitoring period.
The aforementioned study suggests that solar developments can be planned with certain siting and management configurations that are truly beneficial to at-risk animal populations. This supports the idea that solar farms installed on degraded land can have a positive effect on local wildlife. When solar developments advance without taking nature into account, it is up to communities to take a stand. A Senedd petition to “Stop Significant Developments at Gwent SSSI Levels” has received over 6,000 signatures from people across Wales, serving as an inspiring example of community action.
