Page 19 - North American Clean Energy May/June 2020 Issue

costs and/or alter precipitation runoff patterns that may not be acceptable to local code. Make sure to run a geotechnical report to assess rugged ground conditions via in-situ field tests. Worker safety is paramount when installing systems on rugged sites. As large equipment often can’t be used on steep slopes, consider smaller or more agile equipment to clamber up bumpy terrain.
Ultimately, careful evaluation of weather and terrain conditions - along with appropriate sourcing of products suitable to those conditions - helps safeguard plant integrity and performance before the first support structure is put in place.
Michael Faraone Ph.D., P.E. is Director of Engineering at TerraSmart, which has built over 3 GW’s of ground mounted, utility-scale solar projects across the United States. Dr. Faraone joined TerraSmart in 2016, and has been an instrumental leader of the engineering department to develop, analyze, and test the company's innovative solar-racking solutions. His experience
in deep foundations and extended studies in geotechnical engineering has earned him the nickname "Dr. Dirt."
TerraSmart /// www.terrasmart.com
TOUGH TERRAIN
Below the Surface
Rock, clay, sand, and other tenuous ground will impact the foundation that should be used. Knowing how to choose the correct solution will help mitigate any subsurface risk. When working
with bedrock, caliche, volcanic rock,
and glacial till, for example, solutions include pilot hole drilling with a ground screw foundation, or pre-drilling for piles using a concrete encasing. Unlike piles, screws can be embedded without ground modification, and efficiently drill past cobble and buried rocks without refusal -- reducing upfront construction costs and eliminating subsurface risks. For extremely soft soils such as clay, helical piles are a common choice given their large single flight, which helps secure the ground anchor within the soil.
Run for The Hills
Hilly sites require racking structures that are highly adjustable to accommodate undulating ground with relative simplicity. This adjustability can result in huge savings to help minimize civil work and grading on a project.
Most racking vendors are limited
to working with slopes up to 20 or 25 percent. Assess your racking to suit every terrain option with an eye toward nimble design, choosing connections for slope adjustability up to 36 percent. Trackers are more limited when it comes to high sloping terrain, but can be configured to work up to 20 percent.
Getting to Work
Uneven solar locations often require civil work to level your site for mounting. Civil work isn't feasible for every project, as operations like grading can raise
Small Components. Big Impact!
Stäubli Electrical Connectors’ MC4 photovoltaic connectors are the global industry standard and can be found on more PV modules than any other connector system in the world. Stäubli Electrical Connectors, with more than 1.5 billion installed PV connectors across the globe, is an integral part of more than 290 GW (over half) of the worldwide PV capacity.
The MC4 family of PV connectors are rated up to 1500 V UL, 70 A, and are available for 14 through 8 AWG cable configurations. Visit our website for a complete product portflio, including in-line fuses UL rated up to 1500 V, to 30 A.
Contact us today! [email protected] | (707) 838-0530
Purchase online: www.ecs-ecart.com
FAST MOVING TECHNOLOGY
Staubli is a trademark of Stäubli International AG, registered in Switzerland and other countries.© Stäubli 2020 | Photocredits: Stäubli
North American Clean Energy
19