A federal judge Friday denied a challenge to Colorado’s renewable-energy standard, filed by a free-market advocacy group.

U.S. District Court Judge William Martinez dismissed the challenge of the Colorado law that requires larger utilities to get 30 percent of their energy from renewable sources by 2020.

Martinez ruled that the renewable-energy mandate does not violate the U.S. Constitution’s interstate commerce clause, as argued by the Washington, D.C.-based Energy and Environment Legal Institute.

“Plaintiffs have failed to show that the market shift away from coal and hydrocarbon electricity generation substantially burdens interstate commerce,” Martinez said in the decision.

In its lawsuit, the institute had claimed that the renewable-energy statute is “facially discriminatory” because it effectively limits the sale of coal-fired power generated outside of Colorado and then transmitted through regional grids.

“One state may not tell another state’s businesses how to do business,” the institute’s general counsel, David Schnare, said. “Colorado may not tell a utility in Wyoming how to generate electricity.”

He said the energy group probably will appeal the decision.

Renewable-energy advocates hailed the decision.

“We applaud the court for protecting the development of clean energy in Colorado and upholding the intent of Coloradans to move our state toward a future powered by clean, renewable energy,” Sierra Club spokesman Roger Singer said.