ROYALTON — A new Minnesota law requiring investor-owned utilities to get more of their electricity from solar power by the year 2020 means farms like the one Doug and Jane Popp own near Royalton are likely to become a more common sight.

The Popps’ grain bin is powered by a 10-kilowatt solar array, helping to reduce their electric bill. They told the St. Cloud Times the project was affordable thanks in part to financial incentives from their utility, Minnesota Power, and the U.S. Department of Agriculture.

Last week, Gov. Mark Dayton signed the bill setting the new standard that utilities get 1.5 percent of their electricity from solar by 2020. Environmental groups said it might seem small, but believe it will result in a 30-fold increase in solar production by the end of the decade.

“We think it’s a good step forward down what we call the road to clean energy,” said J. Drake Hamilton, science policy director at the nonprofit Fresh Energy. “This is going to maximize the potential for business owners and residents in Minnesota to have access to solar power generation.”

Proponents initially lobbied for a 10-percent standard, while utilities themselves opposed the mandate. House and Senate negotiators finally settled on 1.5 percent, with a goal of reaching 10 percent by 2030.

“It is definitely short of the really strong message that Minnesota needs to become a serious player in solar,” said Eric Jensen, chairman of the Minnesota Renewable Energy Society.

But officials at some of the large utilities predicted it would cause higher electric rates for customers. Right now, Xcel gets a very small amount of its electricity from solar — about 11 megawatts, including electricity purchased from a solar farm at St. John’s University and one near Slayton. Xcel estimates that to meet the new mandate, it will need an additional 275 megawatts of solar by 2020.

“We think that that’s too much solar energy too fast,” said Rick Evans, Xcel’s director of regional government affairs. He said the utility favors moving more toward solar generation as costs drop, but that the mandate will force Xcel to spend money ahead of what the market warrants.

How utilities meet the solar standard remains to be seen. The law requires that a portion of the 1.5 percent requirement come from small solar installations 20 kilowatts or less, the kind that are installed on the roof of a home.

While the mandate applies to investor-owned utilities including Xcel Energy and Duluth-based Minnesota Power, there’s an exemption for member-own cooperatives. Rural co-ops fought to be exempted, arguing it’s impractical and too expensive.

But backers say it’s the boost that Minnesota’s fledgling solar industry needs, and hope it will encourage more home, farm and business owners like the Popps to install solar panels on their roofs or in their yards. Doug Popp described it as doing his part “for our environment and for our children and the next generation.”