Mankato Power Plant

The Mankato Power Plant is a natural gas-fired, combined-cycle facility. This facility was Calpine’s first project in Minnesota and the MRO NERC region.

The facility currently provides electric power to Northern States Power under a 20-year power purchase agreement (PPA) to help meet power needs in Minnesota and the Upper Midwest. The plant is the first large-scale project in Minnesota to use recycled water for cooling. The cooling water for the plant is supplied from the municipal wastewater treatment plant. Calpine paid for improvements to the City’s treatment system that cleans both the water that is used in the power plant and the water that the City discharges to the Minnesota River. Overall, the discharge to the river is significantly cleaner than current and expected future standards.

In addition, a 345-megawatt expansion to the Mankato Power Plant is currently in advanced development to serve a 20-year PPA with Xcel Energy. A natural gas-fired turbine and a heat recovery steam generator will be added, with the incremental steam increasing the power production of the plant’s existing steam turbine and improving the overall efficiency of the plant. The new capacity may begin commercial operation as early as June 2018.


Mankato, MN

Commercial Operation Date:

July 2006

Calpine Net Interest Baseload (MW):

280 megawatts

Calpine Net Interest With Peaking (MW):

375 megawatts


Calpine 100%


Natural gas-fired, combined-cycle


Seimens Westinghouse combustion and Toshiba steam

NERC Region: