Windmills definitely qualify as renewable energy devices. Problem: Conventional windmills eat birds. These two facts set the stage for a possible conflict between bird-fancying environmentalists and wind-energy environmentalists. However there may be a way to resolve the apparent squabble with a technological fix: the Mamikon Spinner design for windmill blades. Preliminary research suggests that birds don’t like Spinners, and that they would be less likely to attempt a shortcut through a Spinner than through conventionally designed windmill blades. More research is needed to determine the relative efficiency of Spinners. There’s ongoing litigation between Mamikon and a company that may be interested in marketing his design; so at the moment, commercial, off-the-shelf windmill Spinners are still vaporware. Here’s a link to a long article about the technical aspects of Mamikon Spinners.
tinyurl.com/cm62cn