Read More: Massive Minnesota Solar Project Gets Major Legal Boost

In an unprecedented decision, a Minnesota judge this week held that utility supplier Xcel Energy should invest in the solar energy developer Geronimo Energy rather than in natural gas generators because that choice is the better economical and environmental deal for the state.

Judge Eric Lipman’s ruling must be approved by the Minnesota Public Utilities Commission, which initially ordered the proceeding to force energy companies to compete on price. The commission is expected to issue its final ruling in March.

Lipman said in the 50-page ruling, issued Tuesday, that the Geronimo project “will have numerous socioeconomic benefits, minimal impacts on the environment and best supports Minnesota’s efforts to reduce greenhouse gases.”

The decision, if approved, would help Xcel fulfill its requirement to attain 1.5 percent of its power from the sun by 2020 under a new state energy law.

Geronimo Vice President Betsy Engelking said the decision marks a turning point for the solar industry because it is the first time that unsubsidized solar energy has gone head-to-head with natural gas resources and been selected as the best option.

“The judge decided that it was the best option for economic and environment reasons,” Engelking told Al Jazeera. “Economically, the judge found that it was the lowest cost option offered.”

If the decision stands, Geronimo plans to build roughly 20 solar arrays at a cost of $250 million.

Gov. Mark Dayton, a Democrat, approved an economic development bill last spring that included a solar energy standard mandating that by 2020, 1.5 percent of the state’s electricity must be solar-generated. Additionally, Minnesota’s Renewable Energy Standard requires utilities to provide 25 percent of their total electrical generation from renewable sources by 2025.

The combustion of fossil fuels to generate electricity is the largest single source of carbon dioxide emissions in the U.S., according to the Environmental Protection Agency. Greenhouse emissions such as carbon dioxide are major contributors to global warming.

The United Nations Intergovernmental Panel on Climate Change (IPCC) estimates that up to 30 percent of plant and animal species face extinction by midcentury if global warming is left unchecked.

Greenpeace spokesman David Pomerantz told Al Jazeera that solar energy “has always been better for our environment” than burning fossil fuels like coal and gas. “Rulings like this one in Minnesota are proving that it’s better for our pocketbooks too. Electric utilities around the country should embrace the solar revolution that their customers are increasingly demanding, or they risk becoming fossils themselves.”

Engelking told Al Jazeera that she expects similar measures to be passed across the country, given that the price of solar energy has come down to the point where it’s comparable to that of natural gas.

She attributes the reduction in solar energy costs to improved technology and fierce competition, particularly from China, which has caused the price to come down “about five years faster than anyone expected it to.”

A majority of states have what is known as Renewable Portfolio Standards (RPS), policies designed to increase generation of electricity from renewable resources, according to the U.S. Energy Information Administration (EIA). These policies require or encourage electricity producers to supply a certain minimum share of their electricity from designated renewable resources.

There is currently no RPS program in place at the national level. However, 30 states and the District of Columbia have enforceable renewable capacity policies as of January 2012, according to the EIA’s website.