Background
The owner/operator of several utility-scale photovoltaic solar facilities reported wind damage to several of its arrays, which comprised a variety of different single-axis tracker systems. Reported damage included buckled drive shafts, bent and separated steel components, weld failures, polymer bearing failures, and cracked and bent photovoltaic panels and supporting steelwork. The reported wind speeds at the sites had not exceeded the design windspeeds for the solar arrays, and the arrays had only been operational for a short period of time.
Services Provided
Rimkus was retained to determine the cause of the damage. Services included the following:
- Conducted an inspection of each array to document site conditions and categorize the different types of damage. Data was collected electronically with hand-held data loggers with proprietary software developed for the project, to facilitate efficient statistical analysis of damage patterns.
- Reviewed construction records and verified as-built conditions.
- Researched weather information and analyzed this data. Analysis of weather data indicated that the winds at the sites were lower than the designed windspeeds for the solar arrays.
- Analyzed field data using a variety of methods including computer modeling using computational fluid dynamics (CFD) and finite element analysis (FEA) of key components to assess the dynamic response of the overall structure and to calculate stresses in key components. Oscillation of the solar arrays developed at below design windspeed conditions for a variety of reasons, and various components were found to be inadequately designed with inadequate connection detailing
- Reviewed on-site testing of the arrays to validate Rimkus’ analysis.
- Prepared a report of findings and produced animated models to explain Rimkus’ findings to the Client and provide advice regarding repair protocols.