Brownfields to Brightfields in Greenfield, Mass. · The landfill also has a storm water management...
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8 BROWNFIELD RENEWAL.COM DEC 2010 – JAN 2011 ENERGY FOCUS Brownfields to Brightfields in Greenfield, Mass. by David Andrews, PE and Robert Jackson, PE A solar farm on a closed landfill in Greenfield, Mass., is expected to save the town some mean green—to the tune of $250,000 in energy costs. A bandoned industrial sites that have been turned into solar facilities, so-called “brightfields” provide economic ben- efits and energy cost savings to local communities. There are, however, unique challenges to the development of these projects. Photovoltaic development on closed landfills in the United States offers an emerging opportunity to utilize renewable energy technolo- gies and redevelop Brownfields sites. However, there are very few in- stallations that have been developed on municipal landfills across the country. In August 2010, the Massachusetts Dept. of Environmental Pro- tection (MassDEP) issued the first-ever Landfill Post Closure Use Permit for a solar facility in the Bay State, paving the way for construction and installation of a 2-MW photovoltaic array on a closed landfill in the town of Greenfield. The keys to success in securing state approval included: (1) creative design and construction planning to protect the low permeability multi-layer landfill cap during construction and op- eration; (2) innovative design of the photovoltaic generation system; and (3) close collaboration with the state, town and developer. This installation will allow Greenfield to transform an otherwise unused town property into a source of clean, renewable energy for the community. Moreover, the town of Greenfield is expecting to save $250,000 in energy costs during the first year of operation. Challenges abound The former Wisdom Way landfill covers 23 acres on the south- west side of Greenfield, Mass. Previously, it had been an open dump- ing ground and then a disposal site for general municipal solid waste and industrial sludge. Capped and closed in the 1990s, the grass cov- ered landfill cap includes a low permeability barrier layer overlain by a 12-inch sand drainage layer and 12-inch vegetative support layer. The landfill also has a storm water management system, and an active gas extraction and treatment system. The solar array planned for installation on this site will consist of 8,918 photovoltaic panels on above-ground racks covering most of the top of the landfill. The installation on the landfill will be con- nected by both above-ground and below-ground cables to two on- landfill large inverters/transformers. A perimeter fence and TV cameras will provide site security. The primary challenge for the project was its unprecedented nature: The state had never permitted a project of this magnitude in the past. In order to gain state approval for the project, it was neces- sary to design, construct and operate the photovoltaic system while ensuring protection of the multilayer low-permeability cover and the integrity of the landfill. The planning had to consider all potential en- gineering and ecological impacts (e.g., landfill settlement and stabil- ity, storm water runoff, and wetlands protection), including impacts to the drainage and gas extraction systems in order to satisfy the state regulators. Project design and construction specifications had to account for the impacts produced by excavation, access road construction, vehic- ular transport and heavy equipment movement, setting concrete, laying of grade stakes, general exposure of land, and contractor foot traffic. Uncharted waters Because this was the first application submitted to the MassDEP to permit a closed landfill for use as a solar farm, project engineers had to develop practical, cost-effective design details, installation spec- ifications, technical approaches and procedures to safeguard the in- tegrity of the landfill cap without the benefit of standard practices. In August 2010, the Massachusetts Dept. of Environmental Protection (MassDEP) issued the first-ever Landfill Post Closure Use Permit for a solar facility in the Bay State, paving the way for construction and installation of a 2-MW photovoltaic array on a closed landfill in the town of Greenfield. Reprinted with permission from Brownfield Renewal Media
Transcript of Brownfields to Brightfields in Greenfield, Mass. · The landfill also has a storm water management...
8 BROWNFIELD RENEWAL.COM DEC 2010 – JAN 2011
ENERGYFOCUS
Brownfields to Brightfieldsin Greenfield, Mass.by David Andrews, PE and Robert Jackson, PE
A solar farm on a closed landfill in Greenfield, Mass., is expected to save the town some mean green—to the tune of $250,000 in energy costs.
A bandoned industrial sites that have been turned into solarfacilities, so-called “brightfields” provide economic ben-efits and energy cost savings to local communities. There
are, however, unique challenges to the development of these projects.
Photovoltaic development on closed landfills in the United Statesoffers an emerging opportunity to utilize renewable energy technolo-gies and redevelop Brownfields sites. However, there are very few in-stallations that have been developed on municipal landfills across thecountry.
In August 2010, the Massachusetts Dept. of Environmental Pro-tection (MassDEP) issued the first-ever Landfill Post Closure Use Permitfor a solar facility in the Bay State, paving the way for constructionand installation of a 2-MW photovoltaic array on a closed landfill inthe town of Greenfield. The keys to success in securing state approvalincluded: (1) creative design and construction planning to protect thelow permeability multi-layer landfill cap during construction and op-eration; (2) innovative design of the photovoltaic generation system;and (3) close collaboration with the state, town and developer.
This installation will allow Greenfield to transform an otherwiseunused town property into a source of clean, renewable energy for thecommunity. Moreover, the town of Greenfield is expecting to save$250,000 in energy costs during the first year of operation.
Challenges abound The former Wisdom Way landfill covers 23 acres on the south-
west side of Greenfield, Mass. Previously, it had been an open dump-ing ground and then a disposal site for general municipal solid wasteand industrial sludge. Capped and closed in the 1990s, the grass cov-ered landfill cap includes a low permeability barrier layer overlain bya 12-inch sand drainage layer and 12-inch vegetative support layer.
The landfill also has a storm water management system, and an activegas extraction and treatment system.
The solar array planned for installation on this site will consist of8,918 photovoltaic panels on above-ground racks covering most ofthe top of the landfill. The installation on the landfill will be con-nected by both above-ground and below-ground cables to two on-landfill large inverters/transformers. A perimeter fence and TVcameras will provide site security.
The primary challenge for the project was its unprecedentednature: The state had never permitted a project of this magnitude inthe past. In order to gain state approval for the project, it was neces-sary to design, construct and operate the photovoltaic system whileensuring protection of the multilayer low-permeability cover and theintegrity of the landfill. The planning had to consider all potential en-gineering and ecological impacts (e.g., landfill settlement and stabil-ity, storm water runoff, and wetlands protection), including impactsto the drainage and gas extraction systems in order to satisfy the stateregulators.
Project design and construction specifications had to account forthe impacts produced by excavation, access road construction, vehic-ular transport and heavy equipment movement, setting concrete,laying of grade stakes, general exposure of land, and contractor foottraffic.
Uncharted waters Because this was the first application submitted to the MassDEP
to permit a closed landfill for use as a solar farm, project engineershad to develop practical, cost-effective design details, installation spec-ifications, technical approaches and procedures to safeguard the in-tegrity of the landfill cap without the benefit of standard practices.
In August 2010, the Massachusetts Dept. of Environmental Protection (MassDEP)issued the first-ever Landfill Post Closure Use Permit for a solar facility in the BayState, paving the way for construction and installation of a 2-MW photovoltaic arrayon a closed landfill in the town of Greenfield.
Reprinted with permission from Brownfield Renewal Media
BROWNFIELD RENEWAL.COM 9DEC 2010 – JAN 2011
ENERGY FOCUS
To overcome the project challenges and obtain the Landfill PostClosure Use Permit, construction logistics were developed to limit theimpacts on the landfill components. For example, site installation willutilize only hand tool and mini-excavator equipment and low-groundpressure equipment to minimize impacts to the landfill liner.
Construction logistics will also includefeatures such as temporary access roads, castin-place concrete placement, prevention ofgrade stake or other markings that coulddamage the landfill liner, segmented workimplementation and full-time constructionoversight to protect the landfill cap. Planswere also developed to monitor the impacton grass growth and erosion during thefirst year of operation.
Teamwork with stakeholders wasinstrumental in achieving this milestonefor the state and the town. Close coor-dination and cooperation with thestate, the developer and the townthroughout the project helped securethe final state approval.
Benefits identified With the award of the Post Closure Use permit in 2010, construc-
tion and installation of the Greenfield Solar Farm is underway andscheduled for completion in the summer of 2011. Converting the
Wisdom Way Landfill into a source of clean renewable energy for thecommunity will provide significant benefits to the state and town.
The project developer, Axio Power, entered into a long-term leasewith the town of Greenfield to use the property. Through a Power Pur-chase Agreement with Axio Power, the town will buy the power pro-duced by the solar panels at reduced cost. It is estimated that the solararray will generate 2,400,000 kWh annually—equal to 45 percent ofall the electricity used by town buildings, including schools. In the firstyear of operation alone, it is expected that the town might save up to$250,000 in energy costs.
In addition to saving money and providing renewable energy forthe community, the Greenfield solar project will support the localeconomy and provide community educational opportunities. LocalMassachusetts firms will be hired to install the solar array and sup-porting electrical equipment, provide long-term maintenance servicesincluding site security and module cleaning. Greenfield is planning tointegrate the landfill solar array into its town-wide “Green Initiatives”Program. A web-based reporting system will grant the public access tothe project’s performance.
The Greenfield Solar Farm is planned to remain on the landfillsite for 30 years, at which time the town may take over operations orhave the array removed and decommissioned. nRnEnN
David Andrews, PE is a senior geo-environmental engineer and Robert Jackson,PE is an environmental engineer with TRC Companies, a national engineeringconsulting and construction management firm that provides integrated services to the energy, environmental and infrastructure markets. http://www.trcsolutions.com
Reprinted with permission from Brownfield Renewal Media
