St. Louis-based builder McCarthy was tapped as the engineering, procurement and construction contractor for the largest solar energy project in Illinois, according to a March 29 release from the contractor. 

The company declined to reveal the cost of the build, but the Illinois Times pegged the price at $535 million late last year. A proposed solar project of a similar size in Virginia was estimated to cost $800 million.  

Construction on the 800MW Double Black Diamond Solar Project, owned by Swift Current Energy and located in Sangamon and Morgan counties, is expected to start in late spring. The plant is scheduled to be commercially operational by fall 2024, according to the company. 

Crews have already begun sitework, and the majority of earthwork, vegetation of the site and stormwater mitigation have been completed, according to a company representative. Peak workforce is expected to be onsite for approximately 14 months, according to McCarthy.

The site will feature 1.6 million solar panels, according to the release, which will rotate to follow the sun’s path across the sky to produce 25% to 30% more power than fixed tilt applications.

The facility will service the city of Chicago as a key end-user and will offset the equivalent emissions of more than 85,000 Illinois households per year, according to the release. 

Starting in 2025, the city will partially source its large energy uses, such as Chicago O’Hare International Airport and Midway International Airport, as well as certain other large facilities with renewable energy from the facility, according to the release. The project is also expected to bring $100 million in tax revenue to Sangamon and Morgan counties.

First Solar is also expanding its U.S. manufacturing footprint, which currently stands at over 5 GW of annual nameplate capacity with three operating factories in Ohio, according to the release.

The company is expected to reach over 10 GW by 2025, when it:

• Completes a $1.1 billion factory in Alabama.
• Completes a $185 million expansion of its existing capacity in Ohio. 
• Invests $270 million in a new research and development innovation center in Ohio.

Solar has become a hotbed of construction activity over the past year — a manufacturing plant for solar panels in Ohio received $600 million in funding, and Reston, Virginia-based Bechtel completed a $140 million solar project in Fort Bend, Texas. Additionally, technology used to build these facilities is garnering interest. Minneapolis-based Mortenson recently piloted robots to install panels on a large-scale solar project.