BRATTLEBORO — In some Vermont towns, old landfills have become hot commodities.
Spurred in part by the state's new net-metering rules, solar developers are scrambling to build photovoltaic arrays on closed, capped landfills that previously had been considered useless for development.
The trend encompasses big arrays - such as a 5-megawatt project slated for Brattleboro's former landfill - as well as smaller arrays that can fit on more compact municipal dumps, like a planned project in Newfane.
While there are engineering hurdles to overcome, developers say it's well worth the effort.
“Up until recently, there hasn't been that much solar on landfills in Vermont,” said Ralph Meima, project development director for Waterbury-based Green Lantern Group. “It's an area that was neglected.”
As Vermont officials have pushed to expand renewable energy generation, the proper siting of such projects has emerged as a major issue.
Wind turbines may be the most contentious example, but solar siting also is up for debate - particularly for those who want to conserve prime agricultural land. So state policies have begun pushing arrays toward land that's already been developed.
For example, Act 174 in 2016 set up “preferred locations” for renewable energy projects including gravel pits, quarries, and landfills. The state's preference for developing solar arrays was further reinforced by new net-metering regulations.
Financial incentives
The state Public Utility Commission's net-metering rule, numbered 5.100 and adopted in June of this year, sets up financial incentives for small-scale solar projects sited on preferred sites including a “sanitary landfill ... provided that the secretary of Natural Resources certifies that the land constitutes such a landfill and is suitable for the development of the plant.”
“Nobody looked at the smaller landfills, as far as I know, until rule 5.100 changed,” Meima said.
Green Lantern is looking to develop solar arrays on former landfills in Cambridge, Dover, and Newfane, and also on a landfill shared by Bethel and Royalton. Each are 150 kilowatt projects.
In an advance notice of the Newfane project filed with the state, Meima summed up the project's attributes this way: The array “will generate local and state tax revenue; will generate lease revenue for the town of Newfane; will maximize the economic use of this parcel; and will further the state's renewable energy goals.”
“Maximizing use” is one key argument for landfill solar: There's not much else municipal officials can do with a closed and capped dump.
“I just think it's a win-win situation for the homeowners and residents of Newfane,” said Carol Hatcher, Newfane Selectboard chair. “It's a perfect place. It's a perfect use of that land.”
The same argument may apply in Wilmington, where Green Lantern is proposing an array on a town-owned parcel next to a closed landfill.
While Wilmington's dump is too steep to build on, the adjoining land - which has been used as a temporary storage area - is a prime spot for a 150 kilowatt solar project and still will qualify as a “preferred site” by state standards, Meima said.
“It's sitting there, available for a better use,” he said.
'No undue adverse impacts'
In pitching the Newfane array, Meima also assured local officials that “there will be no undue adverse impacts from construction or operation of the facility.”
Poor aesthetics are one potential adverse impact of a solar array. But given that landfills tend to be located away from the public eye, some see such sites as ideal hosts for large numbers of solar panels.
The state Public Utility Commission noted that benefit earlier this year when approving a 5-megawatt solar array at Windham Solid Waste Management District in Brattleboro.
“Normally a solar facility of this size would have some adverse aesthetic impacts on the surrounding environment just by virtue of its scale and visibility,” commission members wrote. “However, in this case, the project will be sited on a closed landfill in a heavily developed industrial area.”
Burlington-based Encore Renewable Energy, along with Hong Kong-based Sky Solar, is developing the Brattleboro landfill project, which is net-metered despite its size due to a special statutory exemption. A number of towns and schools are signed up as off-takers and are expecting big utility bill reductions as a result.
Encore also is in the midst of commissioning a 2.1 megawatt, net-metered solar project on South Burlington's landfill.
“The site was identified as opportune for solar because it is proximal to existing infrastructure ... with minimal aesthetic or environmental impacts,” said Derek Moretz, Encore's chief development officer.
In addition to those two large-scale projects, Moretz said Encore is pursuing landfill solar in Wolcott and in Groton, Conn.
Technical challenges
No matter the size of the array, landfill solar presents some logistical difficulties.
Bob Spencer, Windham Solid Waste's executive director, noted that getting the district's 5-megawatt project off the ground was “very time consuming” and expensive: The district incurred a total expense of about $50,000, and a previous developer connected to the project reimbursed half of that.
Given the highly technical nature of the array, Windham Solid Waste needed to hire an expert just to develop a request for proposals at the start of the project. Now, after years of work, construction is scheduled to begin in mid-November and crews “will work throughout winter when weather permits,” Spencer said.
Moretz said building arrays on landfills presents “inherent challenges.”
“Extensive geotechnical and structural engineering is required, along with additional permitting to ensure the landfill cap is not compromised,” he said.
Moretz added that “specialized equipment is required during construction to move about the site,” and foundations require concrete ballast blocks that are more costly than typical solar installations.
Nevertheless, Meima noted that, as long as a landfill is “geotechnically stable, there's an economic incentive to put a solar array there.”
That's not to say, however, that the current landfill solar boom will last: Meima said it could be over within a few years after easily developable sites are snapped up.
Moretz believes the state's new net-metering program, with its emphasis on preferred sites, actually is “a step backwards from the old program” because it limits development.
“There are only a select few landfills in Vermont which can be utilized for solar, in that most are too steep or too small to achieve the scale [needed to] overcome the fixed costs of development,” he said.