Utah is one of the fastest-growing markets in the U.S. for rooftop solar, which is why industry advocates say they’re glad the state Legislature has begun to impose regulations on their businesses.

According to a recent trade-association report by The Solar Foundation, Utah’s solar companies grew by 40 percent in 2017 — the largest jump of any state in the U.S. More than 6,000 Utahns now work in the industry, which is expected to continue growing in coming years.

Solar advocates said they were also happy to see that Utah lawmakers agreed during the recently concluded session on Capitol Hill to extend a system of state tax credits for residential solar installations. The industry believes those tax breaks for homeowners will continue to spur growth in demand for rooftop arrays.

But breakneck expansion has also invited less-scrupulous businesses into the sector, which is why solar industry advocates say they are pleased that earlier this month, Utah lawmakers passed new company disclosure requirements aimed at protecting solar customers.

“Most installations have been very good experiences in Utah,” said Ryan Evans, president of the Utah Solar Energy Association. But there is the “occasional bad actor trying to take advantage of a booming industry. Those are not the actors we want in the industry.”

The new law, which will take effect in September, will require solar sales personnel to provide customers with a set of uniform disclosures. Among other things, the forms will include information about the size of the solar array, when and where it will be installed, and how much it will cost.

The disclosures must also indicate whether a down payment is required, and provide a schedule for future payments.

The law bars solar sales staff from claiming to work for or with a utility company, and provides that the state Division of Consumer Protection will investigate violations and enforce the new rules.

The national Solar Energy Industries Association (SEIA), which helped to draft the disclosure forms on which the new law is based, praised Utah for being the fourth state in the nation to adopt such requirements.

The solar industry relies heavily on word-of-mouth advertising and referrals, said Sean Gallagher, vice president of state affairs for SEIA. So the industry has been pushing for regulation to weed out deceptive sales tactics and other issues that might give it a bad reputation.

“Like any industry, we would have preferred not to need legislation,” Gallagher said. “But we are willing to accept sensible legislation that creates an environment that customers and government can have confidence in.”