In the early days of ground mount solar, load testing was standard protocol. To optimize bankability, project developers and EPCs recognized the importance of assessing geotechnical conditions as a means to make project installation timelines and costs more predictable, reduce risk and improve project outcomes.
Fast forward to today — with the industry’s increasing pressure to cut costs and move at an ever-faster pace, and load testing is too often sacrificed. Organizations who don’t understand the context and importance of project engineering devalue the service claiming that the process takes too long and is too expensive. Racking manufacturers continue to advocate for testing, but when faced with undue pressure to design more quickly and less expensively and ultimately win projects, the scope and quality of pile testing can be negatively impacted.
Though skimping on pile testing may seem like a way to save money and time, the reverse is true. The truth is that proper geotechnical assessment is the real path to measurable project efficiencies:
- Lower Project Costs – Without pile testing, mounting system engineers rely on LPile and AllPile software to model project design. Modeling inherently produces more conservative designs. By contrast, thorough load testing allows engineers to align their designs with actual conditions, reducing the amount of foundation material required and optimizing the mechanical system. Proper design, for example, can reduce necessary embedment depth, which can in turn save significant post-related steel costs.
- Reduced Risk – The lifespan of a ground mount solar project is decades long. While it’s convenient to quickly drive piles into the ground and assume that what stands today will stand tomorrow, building a mounting system to withstand all potential environmental factors for the life of the system requires long-term performance and engineering considerations. What environmental conditions will it be subjected to? What will it have to withstand? Pile testing reveals the full scope of potential structural threats that can’t be anticipated through modeling. A project based on site-specific geotechnical load testing reduces construction and life requirement risks to ensure a project design will stand the test of time
- More Efficient Installation – If installers are forced to show up blind on the project site, it often results in costly delays and change orders. With a pile testing report in hand, they know exactly what they are going to encounter on the surface in the form of vegetation, slopes, water, etc. and what to expect in the subsurface that could impact drive times – such as cobbles, boulders, debris or very firm conditions. Project budgets make assumptions as to how long it will take to drive a pile and move onto the next. If that important variable is not based on the results of a thorough site-specific geotechnical load testing, pile driving timelines can be far greater than expected or assumed. Consider what an increase of two minutes per pile will do to the installation efficiency of a 10 MW project: potentially thousands of dollars in foundation installation and even more in compounding delays.
When faced with the decision as to whether pile testing is an essential step in your next ground mount project, the ROI is clear. Geotechnical understanding makes budgets more reliable, schedules more predictable, engineering increasingly sound and ultimately, projects more bankable over their entire lifespan.
SunLink’s PowerCare geotech engineers can help you put pile testing to work to improve the economics of your next project.