The hidden environmental impacts of some low-carbon energy systems are still to be fully assessed: Low frequency turbine noise making folks ill, turbines killing bats and birds which eat a lot of bugs, thus pushing up farm insecticide use. Tidal tubines silting up estuaries and interfering with lucrative fish/mollusc populations or causing land erosion on coastal areas miles from the sites. Loss of tidal wetlands vital to many migratory birds. There's no such thing as a free lunch.
