Deep Foundations for Solar Arrays

We recently completed extensive design work for the foundations required for Phase I of a very large (300+ MW) solar project, generating designs for three racking systems being investigated by the developer. The structural, geotechnical, and environmental engineering aspects were considered, as well as advanced supply-chain, local component-based manufacturing, installation, and pricing methodologies. The preliminary criteria, provided by the racking companies to perform the engineering, included the spacing of supports, panel layouts, panel angles, and preferred posts. Some wind tunnel test results were also supplied and used to determine alternate designs.

Four foundation designs for each racking system were developed: a Helical Anchor (rotary installation), a Wide Flange Pile, a Pipe Pile, and a Pipe Pile with accompanying wind test results (all vibration installation).

In summary, the installed cost of each of the four foundation designs, ranging from $11.70 - $22.96 per ft, is significantly less than the installed cost of a concrete pile, which can easily run over $45 per ft.

In addition, the total cost per foundation of the four designs ranges from $176 - $427 (with an average of $285), also significantly less than the $450+ total cost of the 10 ft. driven concrete pile previously assumed. This represents a difference, when multiplied by the hundreds of thousands of foundations necessary for all phases in the project, equating to tens of millions of dollars.

Click on the document below and read about the 'Engineered Difference' we bring to providing foundations for solar projects. Included in the document are graphics of sample designs, as well as a set of optional connections to racking systems. It just may be the 'difference' your project will need!