Minnesota utility regulators are facing a controversial choice between solar power and natural gas as the favored energy to generate additional electricity for Xcel Energy Inc.'s 1.2 million customers in the state.
The decision marks the first time these two energy sources have competed head-to-head on price before the state Public Utilities Commission, which is scheduled to decide the question on Thursday in St. Paul.
"You are setting a precedent here that is going to affect future acquisition proceedings," Eric Swanson, an attorney for Invenergy Thermal Development, told the commission Tuesday during an all-day hearing on the competing bids.
At issue is whether Xcel's customers will be best served by $250 million in solar power arrays proposed by Geronimo Energy, a renewable energy developer based in Edina, or by adding generating units at power plants in Burnsville, Cannon Falls or Mankato.
Regulators asked for competing bids from energy developers last year because Xcel Energy and state analysts projected a need for more power in 2017-2019, after the remaining two coal-burning units are retired at Xcel's Black Dog generating station in Burnsville.
That set off a trial-like review before an administrative law judge, who examined the projected need and competing projects' costs, most of which have not been publicly disclosed because the developers consider them trade secrets.
In an unprecedented ruling three months ago, Judge Eric Lipman concluded that Xcel's power needs aren't growing so fast, and recommended Geronimo Energy's plan to build about 20 solar arrays next to Xcel substations as the best deal. If needed, he said, Xcel could temporarily meet unexpected demand by taking an offer from Great River Energy, a cooperative based in Maple Grove, to purchase its extra capacity.
On Tuesday, commissioners heard hours of arguments from Xcel, which proposes to add a natural gas unit at its Black Dog plant, and other competitors. The two other natural gas proposals are from Invenergy Thermal Development, a Chicago-based company that would expand its existing Cannon Falls plant, and Houston-based Calpine, which proposes another unit at its Mankato Energy Center.