Philip Wind Energy Center, Haakon County, South Dakota

South Dakota’s largest wind farm is under construction on the plains north of Philip. Invenergy’s Philip Wind Energy Center is a $750 million project with Blattner, a Quanta Services company, as contractor. Blattner put down its first mud mats in June and fully mobilized crews on July 13, 2026.

The turbine order is now on the record. An Aug. 31 filing by Philip Wind Partners with the South Dakota Public Utilities Commission disclosed a supply agreement with Nordex USA for 55 N163/5.9 MW cold-climate turbines on 108-meter hubs. That’s 324.5 MW of nameplate, with up to 300 MW delivered to the grid, against a permit that allows up to 333 MW and 87 turbines. The PUC approved that permit in February 2026, and chairman Chris Nelson said at the time it would be the state’s largest wind farm.

Project Scope

The project covers roughly 110 square miles in Haakon County, about 85 miles east of Rapid City. The developer’s Sept. 30 monthly report to the PUC listed roads, grading, foundation excavation, rebar, grounding and the first foundation pours. October’s list adds the electrical collection system, with conduit boring and cable trenching, plus grading for the substation and the operations and maintenance building.

Turbine erection runs from June through December 2027 and balance-of-plant work finishes in January 2028. Commercial operation is now set for March 2028, three months later than the December 2027 date in the permit.

The grid connection runs through a 230-kV collector substation and about 5.5 miles of 230-kV generator tie line, with a short tie to an existing Basin Electric Power Cooperative line. The Western Area Power Administration plans a new Philip North Switchyard with two tie-ins to its Oahe-to-New Underwood 230-kV line.

On Oct. 13, the South Dakota Board of Economic Development authorized up to $6.1 million in sales and use tax rebates under the Reinvestment Payment Program. The developer cites about 200 construction jobs, 12 permanent positions and, over 30 years, roughly $85 million in landowner payments and $50 million in property taxes.

Why It Matters

West River South Dakota has wind but not much transmission, and that’s usually what kills projects out there. Philip works because it can tie into existing WAPA and Basin 230-kV lines rather than wait on a new backbone.

The cost works out to about $2.3 million per nameplate megawatt, and the rebate is under 1% of the budget. The gap that remains is the offtaker. Invenergy still hasn’t named a power buyer, and with towers going up next summer, that’s the disclosure to watch.

Project Team & Details