Brian J. Beaudoin, P.E., Project Director, Sanborn Head. Photo Credit: Mike Sears Photography
By GET Staff
Brian J. Beaudoin, P.E., is the Project Director at Sanborn Head & Associates, Inc., which provided engineering support at the Stafford Hill Solar Farm at the closed Rutland City landfill. We had the good fortune to be able to interview him about solar photovoltaic (PV) installations at problem sites.
What are the most important problems that come up with landfills?
There are a few design components that need to be considered when developing solar farms on municipal solid waste landfills that are typically not of concern for greenfield sites. The design needs to address the potential for ongoing long-term settlement of the landfill, protection of the landfill cap, and the risk associated with landfill gas. In addition, because most landfill projects require a ballasted foundation system to protect the cap, the solar arrays can’t be placed on steep slopes for stability reasons.
What are the most important problems that might come up with other problem sites?
Similar to landfills, brownfields sites may be capped; therefore, maintaining the integrity of the cap is an important design consideration. Also, projects that are developed on contaminated sites need to be designed to mitigate the risk of further impact to the environment. Another challenge is that towns and businesses need to make sure that the development of a solar project on a brownfields site is consistent with the approved land use for the subject property.
What would you recommend for a town or business planning for PVs for such a site?
To meet with a developer and engineer that has experience developing landfills and brownfields sites prior to issuing an RFP [request for proposal], so that they get a general understanding of the project requirements and associated additional cost.
Are there solar installers who have specialized in problematic installations, such as those on landfills orbrownfields? How many, would you guess?
Development of solar projects on landfills and brownfields has dramatically increased in the northeastern United States over the last few years. As such, the number of solar installers with experience developing solar projects on landfills and brownfields has increased as well. We have worked with at least six different solar installation companies over the last few years in New England and the eastern United States. I’m sure there are other solar installers with experience developing landfills and brownfields in other regions of the United States as well.
Sanborn Head provided engineering support at the Stafford Hill Solar Farm, Rutland, VT. Photo Credit: Eric Hudiburg
Have you had problems arise because owners of land or solar installers suffer from a lack of experience? What problems?
Fortunately, for the most part, the solar installers that we have worked with have experience developing these types of projects. There is a lot of upfront design and coordination that is incorporated into the development of a solar project on landfill and brownfields sites, which has helped reduce problems during construction. The biggest challenge is getting the owner or developer to understand the increased cost associated with developing these types of projects. Another commonly overlooked design consideration from inexperienced owners and developers is assuming the entire landfill cap can be developed. Many landfills are constructed with steep slopes that are not suitable for the installation of solar arrays because of stability concerns. When an inexperienced entity initially sizes a project, this requirement is often overlooked, and the project is conceptually designed with more capacity than is realistic based on this site constraint.
If solar installers have no experience with the issues and want to install PVs on a problem site, what should they do?
They should consult with an experienced engineer and developer, so that they get a general understanding of the project requirements and associated additional cost.
What benefit does Sanborn Head provide to a town or business with a landfill?
Sanborn Head has over 20 years of experience designing and overseeing construction of landfills, landfill gas collection and conveyance systems, and landfill capping systems. This experience combined with over six years of providing design, permitting, and construction quality assurance services for the development of solar projects allows us to efficiently and properly assist towns or businesses with the design and permitting of these projects.
What trouble could a town or business get into by trying to go it alone?
The design of a solar project on a landfill or brownfields site is more complicated than a greenfield site. If a town or business tries to develop a project on their own, there is a possibility that specific design requirements may not be included, which could result in inadequate design, delayed permitting, and unsafe construction and operating conditions. Although there are additional design considerations needed for the development of solar projects on landfills and brownfields sites, I can’t think of a better use of closed landfills than for the development of solar projects.
Sanborn, Head & Associates, Inc. is an engineering consulting firm specializing in geo-environmental and geotechnical engineering, providing services in Energy, Solid Waste, Developer, Industrial, and Public Sector areas. Contact Brian J. Beaudoin, P.E. at bbeaudoin@sanbornhead.com or (802) 728-8000.
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