U.S. Fish & Wildlife Service officials have suggested that California agencies need to do more research before approving new concentrating solar power tower plants, because of concerns that the solar towers may harm wildlife.

Concentrating solar collectors use mirrors or lenses to focus sunlight and generate heat to create electricity. In some proposed projects, designs include towers that are 750 feet tall, with tens of thousands of mirrored devices to capture sunlight. The towers generate intense radiation, which some biologists believe can harm wildlife through burns or blinding.

At Solar One, a solar power facility that is now decommissioned, many birds were found dead at the site from burns or collisions with mirrors. Bats may also be at risk. Currently, several new projects have been proposed in areas of California and Nevada.

Project developers argue that they’ve designed the plants to avoid harm to birds. New designs have smaller mirrored devices, placed lower to the ground, to help prevent collisions. Developers like BrightSource also choose sites located away from farmed, irrigated land or water that might attract birds and insects. By focusing light in a diffuse ring at the top of towers, they say that they can reduce the chance of burns as well.

The Fish & Wildlife Service isn’t convinced, and thinks more data is needed. They say it isn’t yet clear how different species will react to the towers — for example, if birds will avoid the area — or how the amount of radiation will change through the day. It also isn’t known if the towers will retain heat at night, posing a threat to bats.

Main photo credit: langalex/Flickr