Temperance Solar and Bingham Solar are two projects located in Michigan and are 29.7 MWDC and 29.3 MWDC in size, respectively. Our team, in partnership with J-Ranck Electric, provided civil, structural and electrical engineering, and assisted with commissioning. The substations for each project were prepared in-house under the supervision of our medium/high voltage engineer.
The project was designed with ATI trackers, Bifacial TrinaSolar PV modules and Solectria XGI string inverters. Unique characteristics of the project included custom prefabricated string inverter racks that were dropped in-place for quick and efficient integration on-site. The soils exhibited a high potential for frost heave, which required the use of deep piles to resist the adfreeze uplift forces. The sites were relatively flat, requiring some creative drainage plans for erosion control and storm-water infrastructure.
Commissioning support included measurement and analysis of all PV source circuit I-V curves: over 5,000 strings. Capacity tests were performed per ASTM-E2848-13 on both projects as part of the acceptance by the project’s owner, National Grid. Our team used multiple linear regression (a statistical technique that uses several explanatory variables to predict the outcome of a response variable) to compare actual vs modeled (expected) system performance under the same environmental variables. Both projects were designed simultaneously and were installed on-schedule.