by Diane Mettler
May / June 2016
Citizens Energy Corporation, founded by Joseph P. Kennedy II, has thrown the switch on a 2.5-megawatt solar array on a landfill in Westfield, Massachusetts, turning an unused municipal property into a generator of clean, green renewable energy.
Once a landfill is capped and closed, there's really not much that can be done with it. Most are unbuildable and have ongoing monitoring and maintenance requirements that cost time and money—unless, of course, you're considering a solar facility.
The Westfield landfill in Massachusetts is city-owned and has been capped and closed since the late 1990s. Like many closed landfills, it had become a liability, requiring ongoing maintenance.
The city wanted to change the landfill's status from a property losing money to one generating income for the city. To do that, they decided to turn it into a solar power facility—placing an array on top of the retired landfill, where it was relatively flat. It had been done successfully in other parts of the state, so why not in Westfield?
The city issued an RFP in the fall of 2014, when the state solar renewable energy credits program was in full gear. Citizens Energy Corporation was chosen as Westfield's partner, and the city's 2.5-MW Twiss Street landfill solar project was soon underway.
Emma Kosciak, manager of solar development for Citizens Energy Corporation, says this is a fairly standard way for landfill solar projects to come about. "Today, most landfills in Massachusetts are municipally owned. Because of the high number of municipal landfills, you see a higher percentage of public landfill projects here."
The permitting went smoothly, in large part because Citizens is experienced at developing and operating landfill solar projects. First, they attended a city of Westfield roundtable meeting where all the heads of various departments met to discuss the required permitting. In addition to local permitting, FAA approval was required due to the solar project's proximity to a local airport. A glare study determined the project would not impact aviation, and the FAA issued the approval.
The lengthiest permit process involved a Post Closure Use Permit Application with the Massachusetts Department of Environmental Protection (MassDEP).
"That's a very involved application where we have to provide detailed construction procedures and a whole host of engineering studies including geotechnical analysis, storm water analysis, loading impacts, and so on," explains Kosciak. "As you can imagine, the number one issue for the city, state, and Citizens is to make sure that the landfill is adequately protected."
Although it was lengthy, Citizens' experience and expertise in solar landfill projects, coupled with working with the engineering firm Tighe & Bond, who has been designing and closing landfills for decades, made the process smooth and successful. "MassDEP is also experienced with landfill solar, so they knew what to look for when evaluating the application," says Kosciak.
Citizens' approach to landfill solar is to design everything as minimally intrusive to the cap as possible. "This means the racking system, all the wiring, and concrete pads, everything is built from the ground up, with absolutely no penetrations to the ground of any kind," says Kosciak. The design and construction objective is to not disturb the carefully engineered landfill cap that is protecting the waste mass below.
One of the unique aspects of the design is the racking system, since there are no posts driven into the ground. "We installed the GameChange pour-in-place ballasted racking system. They have a non-penetrating concrete ballast block design. The posts are embedded in the concrete blocks, which are sitting on the surface."
GameChange Solar LLC, which is based in New York (with an office in Massachusetts), provides commercial and utility scale solar racking systems that are said to combine fast installation, quality, and value for both ground and rooftop applications. GameChange is based on the concept of simple innovative design and large-scale volume manufacturing.
In addition to designing a non-penetrating system, a challenge of landfill solar is the fact that a landfill is anything but flat. Over the years there is settlement, which creates a lumpy surface.
"You definitely get some landfill undulations, and most of these landfills have very steep side slopes. We typically don't install on grades above 10 percent, so we can't use the steep side slopes. We just use the flattest plateau portion of the landfill."
Flat is relative when talking about landfills. A company like Citizens can't grade or change the landfill cap in any way and must work with the topography as-is.
"That is one of the reasons that we liked the GameChange system because it is a pour-in-place ballasted system," says Kosciak. "It's self-leveling, which was a nice feature. We are able to get the solar modules all in a straight line, even if the ground beneath isn't."
Construction got underway in October 2014, continuing throughout the fall and into the early winter. One of Citizens' internal requirements is to use all local union labor, and throughout construction, the team was pulled from local union halls in the area. From October to January 2015, when the project came online, the team installed SMA inverters and 6,300 JA Solar 310-watt modules for a 2,000 kW DC system.
Although the team worked in the bitter cold, the project was commissioned before the snow hit. Kosciak says they also had a pretty nice view. "Most landfills are built into tall mounds, and it's not unusual that you have a great view from the top. But this one was particularly beautiful, with the Berkshire Mountains in the background. It is actually like being on a mountain top."
Citizens worked directly with municipal electric utility Westfield Gas and Electric (WG&E) to interconnect the project.
"It was WG&E's first solar project of this scale in the city," says Kosciak. "With that said, they were very confident in their impact studies and interconnection, and they really did a great job."
Citizens Energy Corporation not only develops, finances, and builds the facilities, it also owns and operates them, and they have been operating and maintaining the Twiss Street Solar landfill project for a little over a year now. Everyone is pleased with its performance.
"The city is generating tax revenue, they're saving money on electricity, and they're generating lease revenue as well, so they're pretty happy with the project. They're doing quite well," says Kosciak.
Citizens is pleased too. Twiss Street Solar was one of three solar projects they completed last year, and the company tends to do about 8 to 15 MW a year.
Citizens Energy Corp. got its start a bit differently than most companies. Former Congressman Joseph P. Kennedy II founded the nonprofit company in 1979 to provide low-cost heating oil to the poor and elderly. While successful business ventures in the petroleum industry produced profits to underwrite the costs of heating oil to needy families, Kennedy also started innovative companies in the natural gas, prescription drug, and electricity trading industries. Profits from all the companies have gone to provide basic needs for the poor not just in the U.S., but also in countries in Latin America and Africa where Citizens Energy does business.
"We're a nonprofit company and mission driven," explains Kosciak. "We do 'for profit' businesses, and solar is very much a part of that. It allows us to fund our mission so that we can come back year after year to help people."
To date, Citizens has completed construction of a $100 million portfolio of 23 distributed-solar projects totaling 40 megawatts on the East Coast. As a leader in installing solar arrays on capped and closed landfills, Citizens has four landfill solar projects in operation, and another five landfill solar projects are expected to come online by the end of the year.
There is a good argument for giving landfills a second life as solar facilities. Borrego Solar reported that more than 6,000 landfills in the U.S. were capped from 1988 to 2009, and many are still sitting idle, which demonstrates the tremendous potential for more development. Also, a majority of landfills in the U.S. are located in the sunniest regions of the country—nearly 40 percent in the West and 35 percent in the South—typically in states with solar-friendly policies.
"One of the reasons we really like landfill solar is because they're well sited. They typically can't be developed for any other use. They're environmentally degraded, and they're open fields so there is no shade," says Kosciak. "And often times they have fairly robust electrical service at the site already, which makes interconnection more cost-effective. They're just really naturally good sites for solar."
Landfill solar has other benefits too. The closed landfill generates revenue instead of expenses, and communities gain a sense of pride turning the environmental liability into a clean energy generator.
"I think that's why landfill solar has been so successful in Massachusetts," says Kosciak. "Typically the local community supports developing landfills for solar. It's just a win-win."
At its opening in May 2015, Joseph Kennedy II joined Daniel M. Knapik (Westfield Mayor at the time) to throw the ceremonial switch on the project. The array has already reduced an estimated 2,000 tons of CO2 per year and will produce 2.6 million kilowatt-hours of electricity per year.
"Solar will help solve our country's energy problems for the future," Kennedy said.