Award of Merit Specialty Contracting

Photo courtesy of Swinerton Builders
An innovative racking system was installed by MBL Energy.

This project included installing more than 1 megawatt of elevated solar and roof-mounted solar and an elevated steel structure over a parking lot on an occupied Kaiser Permanente medical office building campus in La Mesa.

One of the main challenges was to meet the highest energy output possible and satisfy the minimum California Solar Initiative reservations, all without hampering Kaiser's daily operations. To keep parking spaces and drive aisles clear, an elevated steel structure, which can span more than 65 ft, was designed, along with cantilevered racking in order to obtain the maximum possible system output.

The design of the specific steel structure to support the solar array combined with the Z-purlin racking system had not previously been installed on a solar project, according to general contractor Swinerton Builders. The racking system is a copyrighted system installed by MBL Energy using parts from its own manufacturer, Beacon Technologies. The installation of the racking, clips and screws was designed with highest efficiency levels in mind. It allowed the subcontractor to install more than 700 panels per day.

The 1-MW-plus solar powerplant has an expected life of 20 years, which should provide Kaiser with benefits for decades to come, Swinerton said.

Key Players

Owner: Recurrent Energy, San Francisco

General Contractor: Swinerton Builders, San Diego

Construction Management: Tetra Tech, San Diego

Lead Design: Swinerton Builders, San Diego

Submitted by:

Swinerton Builders