KNOXVILLE (AP) — Former Tennessee Valley Authority Board Chairman David Freeman this week joined the Southern Alliance for Clean Energy as a senior energy advisor, according to a news release from the group.

Freeman has more than four decades of experience directing energy policies at the federal, regional and local levels, according to the release from the Knoxville-based nonprofit. He is an expert on clean energy, energy efficiency, and the issues surrounding of nuclear power.

"The challenges of how we transition our production and use of energy to cleaner, more efficient, lower-carbon sources have never been greater nor more urgent," Southern Alliance for Clean Energy Executive Director Stephen Smith said in the release. "David's experience and knowledge of these issues are unmatched in the industry."