As it maps out the path to a carbon-free grid, one of Xcel’s biggest challenges is replacing the power lost when its two large coal plants retire by 2030. Contracts with several gas plants that supply significant power to Xcel will expire soon, too.

The company says it needs electricity generators by 2030 that can provide more than 2,200 megawatts of power at any hour of the day, something that wind and solar cannot do. That’s enough energy to serve roughly 2 million homes.

Xcel says it’s not locked into any one technology to provide electricity. That can be determined later, and Xcel doesn’t expect to use gas for all those needs as batteries improve or other options become available.

Shea said Xcel can also renew expiring contracts to buy power from gas plants it doesn’t own.

Yet at the same time, its modeling recommends six or more new gas plants for what it calls “always available” energy. To start, Xcel had asked regulators to approve two new gas plants, one in Cass County, N.D., and another in Lyon County, Minn. They would sit idle most of the time but run when demand peaks, typically on the hottest and coldest days of the year.