INDIANAPOLIS—The Board of Directors of the Midwest Independent Transmission System Operator Inc. recently approved three new applications for membership to the ISO.

Joining the Midwest ISO as transmission owner members are Wisconsin Public Service (WPS) Resources Corp. of Green Bay, WI, and American Transmission Co., LLC of Milwaukee. Independent Power Producer Calpine Corp. of San Jose, CA, joined as a non-transmission owner member, bringing to 23 the number of non-transmission owners who have joined the MISO.

“I am pleased with our continued growth and am happy to welcome Wisconsin Public Service Resource, the American Transmission Co. and Calpine into the MISO fold,” Matthew Cordaro, Midwest ISO president and CEO, told the board at its monthly meeting in Indianapolis.

The Midwest ISO will assume functional control of WPS Resource’s and ATC’s transmission assets when it becomes operational in November next year.

With the addition of WPS and ATC, 16 transmission owners have signed the MISO agreement. They are Alliant Energy, Ameren, American Transmission Co. (Milwaukee, WI) CILCO, Cinergy, Commonwealth Edison, Hoosier Energy Rural Electric Cooperative, Illinois Power, LG&E Corp., Madison Gas & Electric, Northern States Power, Southern Illinois Power Cooperative, Southern Indiana Gas & Electric, Wabash Valley Power Association, Wisconsin Electric and Wisconsin Public Service Resources.

MISO is the nation’s largest independent transmission system operator. When fully operational next year utilities with more than 52,000 miles of transmission lines, 78,000 MW of electric generation, and about $8 billion in installed assets will be participating in the MISO.

WPS Resources Corp. is a holding company based in Green Bay, WI. Its electric utility segment includes two wholly-owned regulated utility subsidiaries, Wisconsin Public Service Corp. serving northeast and central Wisconsin and an adjacent portion of Upper Michigan, and Upper Peninsula Power Co., which serves 48,000 customers in two-thirds of Michigan’s Upper Peninsula.

American Transmission Co. LLC, was formed earlier this year after the Wisconsin state legislature passed a law requiring the state’s utilities to turn over their transmission assets to an ISO. The law was designed to ensure that access to the state’s electric transmission system would remain independent of individual utility control as the industry embraces deregulation.

Calpine Corp. is dedicated to providing customers with reliable and competitively priced electricity. Calpine is focused on clean, efficient combined-cycle, natural gas-fired generation and is the nation’s largest producer of renewable geothermal energy. Calpine has launched the largest power development program in the U.S. To date, the company has approximately 25,700 megawatts of base load capacity and 30,400 megawatts of peaking capacity in operation, under construction and announced development in 27 states and Alberta, Canada.