While he had his problems on the political end of things, Daniel C. Esty was an innovative and effective commissioner at a time when the state needed one, given the merger of environmental and energy policy into a single agency. Since its creation in July 2011, the launch of the Department of Energy and Environmental Protection has for the most part gone smoothly and Mr. Esty deserves much of the credit for that.

On Wednesday, Gov. Dannel P. Malloy announced his commissioner is stepping down Feb. 3 and will return to Yale University in New Haven as director of the Yale Center for Environmental Law and Policy and the Center for Business & Environment.

His time as commissioner of DEEP gave Mr. Esty the opportunity to introduce his academic theories into the real world. Most fundamentally, he sought a more cooperative approach toward environmental regulation and achieving green energy goals, rather than the traditional adversarial relationship between regulators and business. These efforts included the creation of the nation's first "Green Bank" - the Clean Energy Finance and Investment Authority - providing incentives and low-cost financing to encourage renewable energy and conservation.

During his service the state accelerated the permitting process, in large part by improving efficiency and taking advantage of digital technology. So far, at least, these gains in proficiency have not come at the expense of weakening regulatory enforcement.

It was during Mr. Esty's tenure that Connecticut developed its first Comprehensive Energy Strategy plan. Among its key components is a program to significantly expand access to natural gas in Connecticut. It burns cleaner and, due to increased domestic production, is forecast to remain cheaper than other fossil fuels over the long term.

Using a sound business approach, which includes contracts with out-of-state providers, Connecticut, under Mr. Esty's stewardship, is on a course to significantly expand the use of such renewable sources as solar, wind and hydro in meeting the state's energy needs.

Problems on the political side were about to re-emerge, which might account for the timing of the decision. His wife, U.S. Rep. Elizabeth Esty, D-5th District, will be seeking re-election in 2014. Republicans have criticized Rep. Esty for accepting campaign money from corporations subject to regulatory oversight by Mr. Esty's environmental agency. Accusations about conflicts of interest were likely to dog her campaign and hinder her money raising. Mr. Esty's pending departure largely eliminates that political threat.