Similar to ballasted racking’s meteoric rise as the go-to solution for flat roofs, ballasted systems are slowly gaining popularity on the ground. Solar continues to proliferate in rural and landfill landscapes across the country; therefore, solar integrators are beginning to select ballasted ground mounts over traditional pile based systems. Instead of sourcing pipe, dealing with high shipping costs, or renting pile drivers, ballasted ground mounts provide the option of quick installation with lower costs. Ground-ballasted arrays are ideal for landfills, brownfields, and agricultural land with delicate soils that loosen over time.
While pile-driven beams are the standard in solar ground-mounted arrays, unpredictable subterranean conditions are the main reason to search for alternatives. When confronting bedrock or loose soil, man-made ballast trays can be secured to the ground with either ballast blocks or ground screws.
One challenge for ballasted ground mounts in open agrarian fields was their consistent need for operation and maintenance. Since the shade of overgrown grass hampers energy production, the monthly need for grass cutting seemed unappealing to system owners. Recently Aerocompact has raised its tilt legs by 400mm to allow their robot mower to pass through the array easily to prevent shading from overgrowth.
While traditional ground mounts maximize module density, Aerocompact’s new east-west solution G series wastes little space.
Ballasted landfill solar arrays, like the Emerson Street Landfill in Rochester, NY, have turned the previously underused land into major savings for commercial and municipal system owners. In Massachusetts, regulatory factors award developers higher SREC credits for landfill arrays. In order to pursue a successful landfill project, installers should search for flat fields because most dome-shaped landfills are cost prohibitive. Another factor to vet before pursuing landfill solar is to determine if the landfill must be capped to provide a solid foundation for the array.
Ballasted ground mount racking unlocks new solar opportunities with cost competitive racking in difficult terrain, like landfills and agricultural settings with loose soil. New innovations like east-west orientation and robot mowers overcoming some of the challenges to ballasted ground mounts. This will certainly break new ground for installers across the country.