How to choose the photovoltaic support foundation type

What is the best foundation for a ground-mount solar array?

The short answer is: it depends. Ground-mounted arrays penetrate the ground-surface to stabilize the rack structure and have a variety of foundation types.

Why is foundation selection important?

Foundation selection is critical for a cost effective installation of PV solar panel support structures. Lack of proper investigation of subsurface conditions can lead to selection of the wrong foundation type and can result in costly change orders and delays to the job completion date.

What makes a ground-mount Foundation the right fit for a solar project?

Soil composition, local climate conditions, module size, array tilt and other features of the proposed site and array influence what makes a ground-mount foundation the right fit for an individual solar project. “Arrays may be mounted on driven beams, anchor systems, ballasts or hybrid racking systems,” said Bill Taylor, CEO of DCE Solar.

How were PV support structures made?

The driven piles used in the earlier PV support structures were made from hot rolled structural steel shapes such as I beams which were then fabricated by cutting them to length and then drilling, routing, or cutting with lasers holes and slots to enable other parts to fit onto them.

What types of foundations are used in construction?

The support structures are bound to the earth using foundations consisting of driven piles, helical piles, ground screws, concrete footings, concrete ballast or a mixture of these components. The type of foundation used is based mainly on soil properties as well as the geometry of the foundation.

What type of foundation should I use?

If a site contains loose sand and a high water table or otherwise very low soil cohesiveness which would make driven piles or earth-screws unpractical due to requiring extreme embedment depth, and no refusal is encountered, then the preferable foundation type would be a helical pile or ballasted foundation.