JEFFERSON CITY, Mo. (AP) — A Missouri judge has set aside his own previous ruling that sided with energy users and utilities challenging a renewable energy law.

The voter-approved law requires investor-owned utilities to use increasing amounts of renewable resources to produce electricity. State utility regulators were responsible for writing rules to implement it. Those rules were challenged in court, and so was part of the law that dealt with solar rebates.

Cole County Circuit Judge Daniel Green concluded last month that the solar rebate portion was unconstitutional and agreed with the challenge to the rules. However, Green set aside the earlier judgment in a written order provided Friday.

Several others have sought to join the case, including the solar energy industry and renewable energy advocates. Responses to that request are due Aug. 12.

Copyright 2011 The Associated Press.