NASHVILLE, Tenn. (AP) — A lawsuit claims that a federal utility's rate changes discourage homeowners and businesses from renewable energy and energy efficiency measures.

Friends of the Earth U.S., Center for Biological Diversity, Energy Alabama, Gasp and Southern Alliance for Clean Energy sued the Tennessee Valley Authority on Thursday.

The federal lawsuit says TVA reduced large commercial customer rates, introduced a fee regardless of electricity usage that customers are expected to foot, and discounted prices for greater electricity usage.

It says resulting reductions in energy efficiency and renewables mean TVA will increasingly use existing fossil fuel generation, accelerating pollution and climate change.

Utility spokesman Scott Brooks says TVA hasn't been served with the lawsuit yet.

TVA has said the rate is 94 percent variable and can be influenced by energy efficiency and renewable energy.