Brownfields are attractive opportunities for solar development
By Steve Goodbody, EVP of operations and engineering, Soltage
Brightfields, defined by the U.S Department of Energy as solar projects on brownfields (contaminated land or closed landfills), are attractive opportunities for solar developers to diversify their pipeline beyond traditional rooftop and greenfield locations.
The number of potential locations for solar on brownfields is enormous: The EPA has pre-screened more than 80,000 brownfields and contaminated lands for renewable energy, and NREL estimates landfills and other contaminated sites cover 15 million acres across roughly 10,000 closed landfills.
Brownfields often offer development benefits including minimal shade, pre-cleared sites with few other uses and locations in industrial zones near interconnection points and customer demand. Governments frequently offer incentives to improve project economics, creating a win-win for brownfield owners and solar developers.
But while brownfields offer extensive potential, they also pose significant challenges. Steep slopes and impenetrable surfaces historically made many landfills unfeasible for development. Brownfield locations are often contaminated or Superfund sites, requiring remediation and permitting with the EPA or environmental agencies unfamiliar with solar projects.
Location is everything
The right location is important when considering installing solar on brownfields. Developers should seek several key features as they consider sites.
First, is the site near existing grid infrastructure? Many brownfields are located at former industrial sites with substantial distribution-level infrastructure suitable for low-cost interconnection. Second, is the site within a populated area or near large commercial facilities? Energy-intensive consumers like warehouses or factories create behind-the-meter potential for commercial and industrial customers, and population centers expand community solar opportunities.
Because brownfields are often considered environmental concerns, nearby residents will likely welcome solar as a positive use for the land, reducing public hearing requirements. For the same reasons, local governments can be eager to return brownfields to productive use and may offer streamlined permitting and zoning.
Government incentives also extend to professional services. For example, New York City connects developers with engineers, planners, analysts, environmental consultants and attorneys for free liability and remediation consulting. Oakland, California, offers risk-based project standards and a revolving remediation loan fund.
Developers should proceed cautiously, however. While brightfield projects certainly benefit from government involvement, they may also require permits and approvals from federal, state and local agencies that lack familiarity with solar, which may add further development time and effort.
The importance of research
After identifying a promising brownfield, developers should conduct a Phase I environmental site assessment (ESA), engaging a suitably licensed and experienced professional. This involves reviewing site records and interviewing site owners or occupants, often supplemented by additional sampling and testing. The process is exhaustive and provides a full picture of the site’s history and current condition, expediting further permitting. The study may also uncover information gaps requiring further research which should not be ignored—these unknowns are often more important than what is known.
Developers should work with local consultants who understand required permits, tests and inspections. Brightfield projects are lengthy, time-consuming and relatively expensive anyway, so tapping existing knowledge becomes cost-effective over the long run. Experienced consultants can help identify, assess and solve potential contamination and remediation problems. Understanding each site’s individual environmental situation is critical to estimating project cost, scope and timeline—foremost concerns for developers. The earlier challenges are identified, the earlier their impacts and consequences can be understood and addressed. If the magnitude is too great, development should be halted. No two brightfield projects are the same, so a one-size-fits-all strategy won’t work beyond the Phase I ESA.
If contamination is likely, then developers should research site records to identify the site’s history to find out if remediation has occurred, if the site has fallen into disrepair and if there are any long-term obligations a new owner or lessee needs to be aware of. While EPA and state agencies maintain extensive brownfields lists, many have ownership gaps or incomplete documentation, so developers should consult landlords and municipalities for pertinent records.
Three recent brownfield projects from Soltage’s Massachusetts portfolio illustrate these points. In the first example, the Phase I ESA identified historical data inconsistencies that, under one interpretation, suggested potential asbestos material dumping on a portion of the site. If true, this would have significantly limited the project’s size. Rather than simply hoping for the best, we engaged a consultant to excavate sampling pits and test soil to fully determine whether it was contaminated. Fortunately no contamination was found; the 4-MW project proceeded and is now in operation.
In another project, the Phase I ESA determined a portion of the site likely had chemical contamination that, if disturbed, would present a risk to groundwater. Knowing this, we designed the project to avoid contaminated areas and use ballasted racking to minimize ground disturbance. The project size was consequently reduced from 6 to 5 MW, but this avoided groundwater contamination. Proper research allowed project construction with full confidence of success and good conscience.
In a final example, the Phase I ESA determined a potential site contained extensive contamination requiring substantial abatement before any further brightfield development. The inevitable cost and schedule impacts rendered the project uneconomic, and, while disappointing, the Phase I ESA allowed Soltage to cancel the project at an early development stage with little wasted cost or time.
Resolving landfill slope and surface constraints
Understanding a site’s contamination history is critical for all brownfields, but understanding design requirements is especially important for capped landfills. While the height of elevated landfills decreases shading from nearby trees and other obstructions, steep slopes—which can exceed 25% grade—make siting and construction challenging. This is magnified because landfill caps generally cannot be penetrated by racking posts or trenches, requiring fully ballasted systems.
Soltage is currently confronting the steep-slope challenge on three capped landfills in Massachusetts with slopes up to 26% (15°) through a custom ballasted racking design using specialized blocks to secure the solar system to the landfill surface. This approach provides a 20°-tilt ballasted array, raises the array above vegetation growth, leaves landfill surfaces open for landscape maintenance and accommodates existing landfill structures.
Large rewards for getting it right
Developers pursuing brightfield projects should not wear rose-colored glasses. Understanding site history, present condition and construction challenges quickly, and thoroughly is vital to brightfield projects, and developers must properly evaluate the project’s true scope, costs, timeline and risks. In many cases, developers will need to adjust project economics to reflect known realities, and in extreme cases, the project may be terminated as a result. The sooner the better in these unfortunate cases.
Developers should invest the time and effort to realistically assess brightfield projects, make appropriate decisions based upon assessments and be willing to recruit subject matter experts whenever needed. There are no shortcuts with brightfields, but informed developers can reap the rewards of this complex and underserved market segment.