Minnesota utility regulators on Monday authorized more than $500 million in new electrical generating units for Xcel Energy, including the state's largest solar power project.
"It was a big day for solar power," said Nathan Franzen, director of solar power for Geronimo Energy, the Edina-based renewable energy company planning to build the $250 million Aurora solar project by 2017 with panels sited at up to 20 locations across Xcel's service area.
The solar project competed successfully against three other proposed generators fueled by natural gas. In a groundbreaking ruling last December, an administrative judge concluded solar was a better deal.
But the state Public Utilities Commission, concerned about projected future retirements of Midwest coal-fired power plants, on Monday also authorized building two large natural gas-fueled generation units for Xcel's 1.2 million Minnesota electric customers.
One project, proposed by Xcel, would be built at the utility's Black Dog power plant in Burnsville, where two remaining coal-burning units will be retired in 2015. The 210-million-watt turbine will be the second gas-fired generator there. The first was installed in 2002 when two other coal units were repowered.
Calpine Corp., a Houston-based independent power generating company with the nation's largest fleet of natural gas-fired plants, also was a winner in the competition. It was picked to build a 345-million-watt power generator next to its existing gas-generating unit in Mankato.
That project will be the largest combined-cycle natural gas power generator in the state. Combined-cycle plants marry gas turbines, which are similar to jet engines, and traditional steam turbines to extract the most energy from natural gas.
Neither Xcel nor Calpine publicly disclosed the estimated price of their projects, declaring them trade secrets to be shared only with state regulators during the bidding. But the two projects are expected to cost more than $300 million based on typical pricing for such generators.