Dallas-based Leeward Renewable Energy says it will repower its 15-year-old Mendota Hills Wind Farm in Lee County, Ill., replacing 63 Gamesa wind turbines with 29 SG 2.6-126 wind turbines from Siemens Gamesa. Total capacity will increase from roughly 50 MW to 76 MW.

Mendota has been in operation since 2003, making it one of Illinois’ first utility-scale wind farms. Repowering the site entails removing all existing wind turbine generators and replacing them with new equipment to maximize the efficiency, performance and extend the lifespan of the wind farm.

Upon completion, Mendota will operate with fewer turbines, but overall annual energy production is expected to increase three-fold from current facility output.

The project starts in March 2018 and is scheduled for completion in December 2018. Siemens Gamesa will provide operations and maintenance for the Mendota site.