The man who has guided $3.5 billion of federal government investments in new renewable energy technology is stepping down after six years in the job.

Inaugural Australian Renewable Energy Agency chief executive Ivor Frischknecht has told the government he will step down in August rather than seek a third term in the job.

Energy Minister Josh Frydenberg thanked Mr Frischknecht for his contributions since 2012, saying he had helped to make ARENA a success with his expertise in energy, innovation and early-stage investment.