American Transmission Co., Pewaukee, Wis., has proposed making $3.4 billion in Wisconsin-focused power-line upgrades—a portion of what could be a roughly $25-billion transmission build-out designed to deliver thousands of megawatts of renewable power from the Great Plains states across the Midwest.

 Minnesota leads way in transmission line projects worth up to $26 billion.
Map:Sue Pearsall For ENR
Minnesota leads way in transmission line projects worth up to $26 billion. Source: American Transmission Co.

The focus on expanded transmission capacity is driven by state renewable-energy requirements. A transmission assessment conducted in July by Houston-based Quanta Services estimated that 11 Midwest states would need roughly 47,000 MW of new wind generation to meet 80% of existing or planned renewable requirements at a cost of $24 billion to $26 billion.

Some of that needed transmission is already under construction.

The CapX2020 project in Minnesota is the most advanced large-scale renewable-related transmission project in the Midwest. The project, being developed by a consortium of 11 utilities, includes four individual projects that will help deliver renewable generation from the Dakotas and Minnesota to key markets while also improving grid reliability.

The $1.7-billion CapX2020 project includes 345-kV lines running from Minnesota into North Dakota, South Dakota and Wisconsin. The lines are in various stages of regulatory review, and all are expected to be in service by 2015, according to Tim Carlsgaard, a spokesman for the transmission consortium.

Minneapolis-based Xcel Energy has started building the first leg of the Monticello, Minn., to Fargo, N.D., line, Carlsgaard says. The CapX2020 participants have not decided if they will hire a contractor to build the rest of the line, he said. Also, construction is expected to start by the end of the year on a 70-mile, 230-kV central Minnesota project, he says. Both lines will allow renewable developers in North Dakota and western Minnesota to deliver power to the east. The Capx2020 utilities are poised to propose a second round of renewable-related transmission projects, Carlsgaard says.