Biosar-Aurora Solar, Minneapolis, MN
Biosar America LLC was contracted by Enel Green Power North America to work on 16 different project sites in the Minneapolis, Minnesota area. The client needed foundations for inverter cabins on this 150 MW solar project as well as foundations and poles for their network of CCTV cameras. The project faced a compressed schedule from initial contact to scheduled project completion, and geotechnical reports indicated many of the sites contained soil that was filled with cobbles. Initially, Almita’s role on this project was limited to supplying the necessary helical piles.
Despite originally being a pile supply only job, Almita’s experience with other solar projects convinced the client that Almita was the right company to handle both the supply and install. Almita proposed a very cost effective solution to supply and install both the foundations and poles for the CCTV cameras. These were originally intended for concrete, but Almita provided a cost saving solution for this client resulting in the switch. Geotechnical Analysis indicated that some extensions would be needed, and Almita used a bolted coupler design for faster installation. To address cobbles in the soil, piles were custom designed with smaller diameter helixes and the helix thickness, and helix thickness was also increased from 1/2" to 3/4" to handle rock encounters.
The client had never used helical piles for their previous solar projects, but had an excellent experience working with Almita. We were able to mobilize within one week from contract award to ensure that the client’s schedule was met. Our experienced site staff were able to identify soils challenges on site and were able to identify which helix diameter would work best in which locations.