Swift Current began construction on the 3,800-acre, 593-megawatt solar farm in central Illinois as part of the same five-year, $422 million agreement. Straddling two counties in central Illinois, the Double Black Diamond Solar project is now the largest solar installation east of the Mississippi River. It can produce enough electricity to power more than 100,000 homes, according to Swift Current’s vice president of origination, Caroline Mann.

Chicago alone has agreed to purchase approximately half the installation’s total output, which will cover about 70 percent of its municipal buildings’ electricity needs. City officials plan to cover the remaining 30 percent through the purchase of renewable energy credits.