Projects
Salt Creek Substation
Market
Application
Dose Rate
Project Overview
- Building pad for a substation on a solar farm in IL
- A blend of quicklime and cement was utilized on the jobsite to achieve the required strength
- The soil reached the desired temperature/ strength and the project was completed on time
Background
The demand for solar energy is rapidly increasing across the country as more people and businesses seek sustainable and renewable energy solutions. Over 21 gigawatts (GW) were installed in the United States in the first half of 2024 alone, marking the strongest first half in the industry’s history. Solar farms are being built nationwide to meet this demand and a substation is needed to connect the farm to the electrical grid.
This project is the build of a substation on a solar farm in Mason County, IL. Illinois has a rapidly expanding solar industry and plans to have 25% of its electricity generated by renewable sources by 2025.
The Challenge
A stabilized ground is crucial in the construction of a substation for a solar farm because it ensures the structural integrity and safety of the facility. The days preceding this project were quite frigid and wet, resulting in cold and saturated soil. Because the foundation was not workable in those conditions, it posed a serious issue as this project was on operating on a tight timeline.
The Solution
Given the cold and wet conditions of the soil, it was determined that quicklime was needed for this project to move forward. The high availability of calcium oxide in quicklime creates exothermic reactions and quickly drives off moisture. Quicklime would not only dry the soil, but also heat the ground ahead of the cement treatment. Mintek support worked with the Dunn Company to help them relay the benefit of cold weather liming to the project owner to gain buy-in.
Implementation
Quicklime was used at a 3% dose rate to dry, modify, & stabilize the soil prior to cement treatment. The product was delivered to the job site day of via pneumatic tanker. Spreader trucks and reclaimers were utilized to evenly disperse and mix quicklime into the soil.
Results
The ground temperature was heated by 25°F after quicklime was mixed into the soil. Despite the cold and unworkable weather conditions, the construction project was back on track after the quicklime treatment! The crew was able to process the second lift with cement the next day and stay on schedule.
Salt Creek Substation
Case Study
“Thank you for the guidance on the project at Mason County. The processed quick lime behaved as you said it would and served its purpose in the design. One thing I found interesting was the drastic rise in soil temperature (nearly 25 degrees). Aside from acting as a drying agent, the bottom lift of lime also warmed the lift of soil placed on top of it. A dunn crew then processed the 2nd lift with cement the following day. I was originally concerned the soil would be too cold to process cement, but the lime treated lift below kept it warm. Thanks again for the help. ”