A project to build what would be the largest solar farm in Illinois is set to get underway this spring.

Owner Swift Current Energy recently selected McCarthy Building Cos. as the engineering, procurement and construction contractor for its 592-MW Double Black Diamond solar project in Morgan and Sangamon counties in central Illinois. Swift Current did not disclose the current price estimate for the project, but a company representative told local officials in 2021 that the project would cost more than $535 million to build. 

Swift Current anticipates 435 craftworkers will contribute to the project. Early site work has begun, and peak workforce construction on site is expected to last 14 months. The facility is expected to begin operating by the fall of next year. 

Scott Canada, executive vice president of McCarthy’s renewable energy and storage unit, said in a statement that the project is part of “expansive growth of utility-scale solar construction throughout the country.” As of the end of last year, Illinois has 2,036 MW of installed solar capacity, according to the Solar Energy Industries Association. The group projects 5,696 MW in growth for the state over the next five years. 

This project would include enough capacity to power more than 85,000 homes, according to Swift Current. However, most of the electricity it generates will actually go to large facilities owned by the city of Chicago, including O’Hare and Midway airports, a library and a water purification plant. Chicago officials signed an agreement with power supplier Constellation, which is working with Swift Current, to purchase electricity from the facility as part of a city government plan to use 100% clean, renewable energy for city facilities starting in 2025. Other customers for Double Black Diamond include companies State Farm and PPG, according to Swift Current.

Manufacturer First Solar is providing solar modules for the project. Swift Current says Double Black Diamond is set to include 1.6 million panels, most of which will be manufactured in the U.S. The company is currently in the midst of projects including building a $1.1-billion production plant in Alabama and expanding its Ohio plant. 

Another company, Nextracker, is providing smart solar trackers, which rotate panels to follow the sun across the sky and maximize panel output. The company says smart solar systems have gains of 25-30% compared to fixed-tilt panels. 

Swift Current CEO Eric Lammers emphasized in a statement that U.S.-based businesses are building the project and providing its solar equipment. The Inflation Reduction Act, which Congress passed last year, allows solar project owners to claim either an investment tax credit or production tax credit, provided they meet requirements including made-in-America provisions. 

“The Double Black Diamond solar project brings together American-based businesses McCarthy, First Solar and Nextracker to construct a market-leading project that we hope will serve as an example for other projects to come,” Lammers said.