Ground-Mounted Racking Considerations: Page 7 of 7

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Site Grading, Landfill Deployments, Bonding and Earthing, and Mass Custo
  • Ground-Mounted Racking Considerations
    Ground-Mounted Racking Considerations
  • High and dry
    Designers should ensure that electrical equipment is above the reach of flood waters. AHJs may also require the use of raised-earth pads for major electrical equipment, including substations,...
  • Borrego Solar 1.3 MW PV system
    Borrego Solar deployed this 1.3 MW PV system at an active landfill in Maine. The site also includes an 8 MW power plant fueled by captured methane gas.
  • A ballasted fence
    A ballasted fence at the array perimeter is a good option for minimizing fencing costs on landfill projects.
  • Working with ballast blocks
    Designers can determine the size and shape of ballast blocks by considering soil bearing pressure and design loads dictated by the local building code.
  • Self-grounding clamp from SunModo
    Mounting systems listed to UL 2703 include integrated bonding components—such as this self-grounding clamp from SunModo—that have undergone accelerated lifecycle testing.
  • Ground ring for solar energy system
    Grounding electrodes—such as the ground ring beneath this inverter pad—establish a direct connection to earth. To limit voltage to ground within a ground-mounted PV array, system designers can extend...
  • Prepare for the unexpected on solar energy project
    Project developers can avoid costly delays by working with products that allow for interchangeable foundation options.
  • Solar Energy mounting systems with terrain-following capabilities
    Mounting systems with terrain-following capabilities may enable project developers to cost-effectively deploy PV systems on marginal sites.
  • Ground-Mounted Racking Considerations
  • High and dry
  • Borrego Solar 1.3 MW PV system
  • A ballasted fence
  • Working with ballast blocks
  • Self-grounding clamp from SunModo
  • Ground ring for solar energy system
  • Prepare for the unexpected on solar energy project
  • Solar Energy mounting systems with terrain-following capabilities

Part 4: Scalable Mounting Solutions

By Keith Beisner and Sara Jacobs

The increased rate of solar adoption is opening up new markets to solar providers and ramping up project volumes. Developers, EPC firms and solar providers are seeing an increased number of project opportunities as well as a wider range of project sizes across their portfolios. In addition, the solar industry’s footprint is expanding into all regions of the US, from the remotest rural areas to the tightest urban spaces.

Rapid market expansion means that solar solution providers must streamline their designs across a wide range of environmental conditions. Solar installers have to be prepared to deal with variable surface and subsurface conditions. At the same time, the industry is under great pressure to lower costs. These realities require new solutions. Solar providers and EPC firms require a new generation of efficient, cost-effective solutions that enable them to better react and adapt. 

MASS CUSTOMIZATION

The key to making solar happen in more places while driving costs down lies in having a mounting-system design that is centered upon built-in environmental adaptability, construction flexibility and predictable costs. Developing customized solutions on a site-specific basis is not a scalable strategy. Instead, the industry needs racking systems composed of standard components that installers can assemble in a variety of ways to meet each project’s unique challenges. This mass customization approach will allow the industry to accelerate most rapidly because it is both highly configurable and cost effective.

Foundation design. Installers need different foundation options to avoid costly delays caused by variable soil conditions and unpredictable subsurface obstructions within a project portfolio. To achieve economies of scale, however, it is essential that these foundation options be part of a standardized product solution. Taking the need for foundation flexibility a step further, soil conditions can vary dramatically within a site, meaning even a single project may require a range of optimal foundations. The key is to provide a range of standardized foundation options that developers can easily interchange without having a negative impact on the overall system design or aesthetics.

If project developers discover the need for diverse foundations during the engineering design phase or preconstruction pull tests, mass customization allows designers to optimally specify different foundation types before construction starts. Often, though, EPC firms do not discover these soil variations until installation work is already in progress. When installers must quickly react to problems without a ready-made solution on hand, delays and escalating costs are the norm.

Product designs that allow for swap-in foundation changes can equip installers to make on-the-fly changes during construction without incurring high costs for replacement parts and project delays. For example, if installers hit a refusal while driving a post on-site, they might quickly swap in a cast-in-place ballasted foundation on top of the soil while utilizing the same superstructure. Readily available and interchangeable foundation options can help eliminate expensive in-field modifications.

Mounting structure. When it comes to the racking structure itself, mass-customized solutions provide design flexibility to accommodate project variations, including different modules, terrains, and wind or snow loads. Although 72-cell modules are the de facto standard on ground-mount projects, each module frame has its own distinct set of mounting dimensions. Mounting systems that are adaptable to different modules without component modification eliminate the need for last-minute change orders.

Similarly, standardized products with terrain-following capabilities reduce not only site preparation and installation time, but also PV system cost and complexity. In recent years, the scope of projects has grown to include not only flat, level and prepared sites but also more-challenging sites with undulating slopes or hilly terrain. Mounting systems that installers can deploy without making major site improvements or modifications can reduce preconstruction civil work and improve project economics.

As solar projects expand into regions with higher wind and snow loads, mounting systems must also adapt to these environmental conditions. Standardizing products to accommodate higher loads without the need for custom components simplifies both the design and the supply chain processes. This simplification allows optimal project delivery timelines and improved cost efficiencies.

Soft costs. Beyond material costs, mass customization also shaves project soft costs. Many developers and customers are seeking better-integrated electrical and mechanical designs across their project portfolios. Mounting solutions with standardized table sizes—such as two-high in portrait configuration—make this integration possible. Different foundation configuration options, meanwhile, can accommodate changing environmental factors while keeping other variables, including table size and mechanical and electrical components, consistent across multiple project sites. Standardizing these mechanical and electrical design processes can lower costs and increase engineering efficiency while allowing for easy preparation, installation and O&M.

THE DOMINO EFFECT

A domino effect begins to take place when product design and engineering become more efficient. Solar providers, large and small, can take on more projects in more locations. While these growth factors place a high demand on materials, mass customization also streamlines supply chains. It allows companies to inventory components and reduce lead times. It accommodates short-notice schedule or design changes. This adaptability is critical to companies with aggressive and sometimes simultaneous or competing construction schedules.

Furthermore, the ability to use the same system and components on all sites, regardless of environmental and site conditions, allows installers to implement best practices more consistently and can dramatically improve installation efficiencies. On-site crews learn to quickly troubleshoot unpredictable situations and implement rapid, cost-effective mitigation solutions while also reducing punch lists and mitigation work.

With the combined advantages of mass customization, solar providers gain maximum efficiency and achieve economies of scale across projects of all sizes. Mass customization reduces costs and allows rapid growth in nonresidential markets where ground mounts are typically deployed. The result is more successful solar projects and a faster technology adoption trajectory.

Contact:

Keith Beisner / SunLink / San Rafael, CA / sunlink.com

Marvin Hamon / Hamon Engineering / Alameda, CA / hamonengineering.com

Sara Jacobs / SunLink / San Rafael, CA / sunlink.com

Samuel Laughlin / Blue Oak Energy / Davis, CA / blueoakenergy.com

Bryan Morrison / Borrego Solar / Lowell, MA / borregosolar.com

Bill Reaugh / Blue Oak Energy / Davis, CA / blueoakenergy.com

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