New Jersey continues to go with green energy
The Garden State is getting greener with the installation of solar farms on mothballed landfills-New Jersey power utility PSE&G recently completed its largest solar project to date, the Kinsley landfill, which is now delivering 11.18 megawatts of sol
By Tony Kryzanowski
The remarkable ability to make lemonade when life serves up lemons was once again demonstrated recently with the successful conversion of part of the mothballed Kinsley landfill site in Deptford, New Jersey, into a 11.18-megawatt (MW) solar power farm, which is now delivering green energy.
The project is the largest solar farm built so far by New Jersey power utility Public Service Electric and Gas Company (PSE&G) as part of its Solar 4 All program.
The Kinsley solar power array covers 35 acres of the 140-acre decommissioned landfill site owned by Kinsley Landfill Inc (a division of Transtech Industries), which was highly supportive of the solar power project.
Dan Edwards, Transtech Industries president and CEO, says an important part of the project's success was the teamwork to put the project together on both the government and corporate level, describing the project as, "an all-around environmental and energy win." They are considering future expansion of the solar farm.
Since 2009, PSE&G has invested over $515 million in its Solar 4 All program, using solar renewable energy certificates (SRECs) and federal investment tax credits to help offset the cost of the program. Its goal is to develop 125 MW of solar power using landfill and brownfield sites, rooftops, parking lots, solar farms, and utility poles to supply a total of about 20,000 homes.
After approving an initial 80 MW under the first phase of the Solar 4 All program, the New Jersey Board of Public Utilities approved an extension to the program in 2013 for an additional 45 MWs. The Kinsley solar power project and the 10.14-MW solar power project on the Parklands landfill site owned by Waste Management in Bordentown, New Jersey, were built as part of this extension. Both projects were brought on line in December 2014 and together supply enough power for 3500 homes. They also reduce carbon dioxide emissions by 15,000 tons by offsetting power generation from traditional fossil fuel sources.
Despite its location on the East Coast, far from the Sunbelt of the U.S. Southwest, New Jersey is the third largest solar power producer in the United States, as well as the third largest provider of jobs in this sector, behind California and Arizona. The Kinsley and Parklands projects alone provided about 200 jobs.
The Kinsley landfill in Deptford ceased operations in 1987. This was a key condition in PSE&G's site selection process to identify potential landfill sites for solar installations. They had to be properly decommissioned and proven stable for a number of years. Sites also had to be located for easy tie-in to the power grid.
So far, PSE&G has built seven of its 26 solar farms on either landfill or brownfield sites, putting 110 acres back into productive use with the installation of 106,000 solar panels generating 31 MWs of power for a total of 5000 homes.
In addition to 26 solar farms, 174,000 pole-attached solar units have also been installed as part of the program, for total production to date of 101 MW. The power is sold as part of the utility's standard power supply to all its customers.
Joe Forline, vice president for Customer Solutions at PSE&G, says putting solar farms on these landfill and brownfield sites is excellent use of these properties that would otherwise have "very limited opportunities for development," while maintaining the state's sparse amount of open space.
New Jersey-based Conti Enterprises was awarded the engineering, procurement, and construction (EPC) contract on the nearly $25 million Kinsley solar project. Matthew Skidmore, Conti vice president, says the company had experience with the Solar 4 All program and had done another landfill solar farm project for PSE&G in 2009. Conti was also the EPC on the Parklands project.
Skidmore says that developing solar installations on sites like decommissioned landfills is a natural business extension for the company as it has safely decommissioned more than 50 landfill sites in the U.S. They have the technical experience to address the specific challenges that these sites present for construction of projects like solar farms, and so far, they have already constructed over 35 MWs of solar power on landfills.
From a technical standpoint, what made the conversion of the Kinsley landfill into a solar farm possible was the use of a surface racking and wiring system capable of withstanding the gamut of weather conditions that can occur in New Jersey, while ensuring that the landfill's protective cap was not disturbed and that the project was still economical.
The anchors for the racking system are 3,495 precast concrete ballast blocks that Conti supplied based on RBI Solar's design. Conti had experience with this type of ground mounting system from its first Solar 4 All project in 2009, along with other ground-mounted landfill projects. RBI Solar, a specialist in solar mounting systems, supplied the racking for both the Kinsley project and the Parklands project. They were pre-assembled before shipment to the jobsite for installation.
|New Jersey power utility PSE&G has built seven of its 26 solar farms on either landfill or brownfield sites, putting 110 acres back into productive use with the installation of 106,000 solar panels generating 31 MWs of power for a total of 5,000 homes.|
Skidmore says working on a landfill is not like working on any other piece of ground because there is municipal waste that has been settling and decomposing for a number of years. Conti brought in about 100,000 tons of clean fill material to level out the Kinsley site prior to the solar farm installation because the ground was very undulating from the settlement it had experienced over the years.
"You have a liner and a cap on these sites that, if damaged, can cause some real long-term concern for the facility," he says. "So maintaining and ensuring the integrity of that cap for the duration of not only the project, but also the lifespan of the solar system over 20 to 25 years, has a fair amount of importance."
Obviously, design of a racking and wiring system with minimal ground disturbance characteristics is an important part of a successful project, and Skidmore says the fact that RBI Solar offered a pre-assembled solution went a long way to minimizing the possibility of disturbing the ground cover. He says it probably increased the cost of the project, versus a standard ground-mounted system, between 15 cents to 20 cents on a cost per watt basis, or seven percent to 10 percent, depending on the scale of the project. Using the non-ground penetrating system also took about 10 percent longer because of the need to procure non-traditional, precast concrete ballasts instead of traditional posts, which are typically stock items.
RBI Solar sales manager Pat Hudepohl says the landfill racking system they have developed with the concrete ballast blocks is designed to work with landfill contours and all solar module types. They are in the process of introducing a new ballast design for the market.
|The anchors for the racking system on the Kinsley landfill solar project are 3,495 precast concrete ballast blocks that were supplied by Conti Enterprises (the engineering, procurement, and construction contractor), based on RBI Solar's design.|
"We had adjustments built into the racking system where, from east to west and north to south, the system would have about six inches of adjustment to address the slope of the site," he says. The overall goal with designing the concrete ballasts in-house and pre-casting the ballasts with support poles in place for delivery to the construction site was to reduce the installation time and eliminate such variables as possible weather delays, while using labor efficiently. The ballast blocks could be removed from flatbed trucks and put in place immediately. The system was also designed so that the number of connection points in the field was reduced by about 75 percent.
"We have used this same design on one of the largest landfills in California, and we have another one coming up in Vermont," says Hudepohl. "We think that stable landfills will become a larger portion of the solar industry as more land becomes less readily available." The ballast block sizes can be adjusted for each landfill, as required.
Skidmore says that RBI offered a very technically sound structure solution that meets the requirements of iy
Another challenge to building the Kinsley landfill solar farm was the confined construction space to minimize the possibility of ground disturbance. This added to the stress of having to complete the project over five months. Construction began in August, 2014, and it was completed at the end of the year. Skidmore says working with RBI Solar really paid off because pre-assembled components arrived on site exactly when they were slated to arrive.
All the wiring was installed above ground in cable trays, and flexibility was designed into the electrical connections to take into account further potential settling of the landfill.
Given the nature of the construction site, extra safety measures were required for workers. For example, there was onsite air monitoring, and although no hazardous conditions were experienced during construction, there were safety protocols in place and workers were trained in what to do in the event of a hazardous situation.
A total of 36,841 Canadian Solar 305-watt peak solar panels were installed on the RBI Solar-supplied racking system. The inverter supplier was ABB. The electrical substation, provided by Eaton, was constructed off the landfill site but directly adjacent to the solar farm.
Conti Enterprises worked with engineering firm T & M Associates and MFS Consulting Engineers on the project, and the main electrical contractor was Huen Electric.
Skidmore says construction of solar farms on underutilized land like decommissioned landfills is becoming more commonplace throughout the U.S. In terms of pre-existing conditions where a decommissioned landfill could be transformed into a solar farm, he says that a site should be closed for at least 15 to 20 years, with relatively flat contour, and a usable space of at least 5 to 10 acres, with an optimal amount being in the 30-acre range.