Revised MISO deal covers expansion of Calpine’s Mankato plant

The Midcontinent Independent System Operator on Oct. 15 filed with the Federal Energy Regulatory Commission an agreement that covers a planned expansion of the gas-fired Mankato Energy Center LLC facility in Minnesota.

MISO filed an Amended and Restated Generator Interconnection Agreement that is with Mankato Energy Center LLC as the “Interconnection Customer” and with transmission owner Northern States Power.

“This filing amends the Original Agreement to reflect that the Interconnection Customer is completing its build out of the Large Generating Facility which requires installation of Network Upgrades on the Transmission Owner’s Transmission System,” said the filing. “Phase 1 has been completed and updates have been reflected in this Interconnection Agreement. The Interconnection Service provided under this Interconnection Agreement for Phase 2 is conditional [Energy Resource Interconnection Service] that will convert to [Network Resource Interconnection Service] upon completion of all Network Upgrades identified in this GIA (including upgrades on affected systems and upgrades required in Appendix A10).”

The deal covers a 922 MVA facility, rated at 682 MW summer gross and 757 MW winter gross and 667 MW summer net and 740 MW winter net, with all studies performed at or below the 667 MW output limit. This generating facility is composed of three units in a combined cycle configuration rated at 226 MVA for combustion turbine generator no. 1, 226 MVA for combustion turbine generator no. 2 and 470 MVA for the steam turbine generator.

The completed Phase 1 involved the installation of the first 226 MVA combustion turbine generator and the 470 MVA steam turbine generator. Phase 2 consists of installing the second 226 MVA combustion turbine.

The in-service dates are:

  • Phase 1 – July 1, 2006; and
  • Phase 2 – original date was June 1, 2007, and the expected new date is June 1, 2018.

A project contact is: Brett Kruse, Mankato Energy Center LLC, Calpine Energy Services, 717 Texas Ave., Suite 1000, Houston, TX 77002, Voice – 713-830-8732, Fax – 713-830-8705, Email –

Calpine has been trying to bid this new capacity at Mankato into Northern States Power. But the utility told the Minnesota Public Utilities Commission on Sept. 23 that a recent downward revision in its power demand forecast calls into question the need in the near term for new purchased power agreements for gas-fired capacity, including the Mankato capacity.

Northern States Power, a unit of Xcel Energy (NYSE: XEL), also filed draft Power Purchase Agreements (PPAs) with Calpine and Invenergy, and price terms for its own gas-fired Black Dog Unit 6 self-build option, so that the commission can determine which of these project(s), if any, best addresses the company’s overall system needs. It also filed a draft PPA with Geronimo Energy for commission review to ensure that the negotiated terms for the Aurora solar project, which is a series of distributed solar projects, are consistent with the public interest.

About Barry Cassell 20414 Articles
Barry Cassell is Chief Analyst for GenerationHub covering coal and emission controls issues, projects and policy. He has covered the coal and power generation industry for more than 24 years, beginning in November 2011 at GenerationHub and prior to that as editor of SNL Energy’s Coal Report. He was formerly with Coal Outlook for 15 years as the publication’s editor and contributing writer, and prior to that he was editor of Coal & Synfuels Technology and associate editor of The Energy Report. He has a bachelor’s degree from Central Michigan University.