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Community Solar Gardens Sprout From Contaminated Sites

Garfield County Community Solar Array
Shiny solar electric panels will soon be constructed where redwood barrels once cured 5,000 tons of pickles. The former Dreher Pickle plant, which operated from 1921 to 1988 in Fort Collins, Colo. will be revitalized by community solar developer Clean Energy Collective (CEC) to produce renewable energy for local residents.

Railroad tracks dissect the six-acre parcel of land at the corner of Riverside Avenue and Mulberry Street, and the soil has been contaminated with salt from pickling operations over the years—limiting the redevelopment options. “The proposed community solar project is one of the few uses we’ve been able to suggest for an otherwise difficult brownfield property owned by the city,” said Norm Weaver of Fort Collins Utilities. Acknowledging the unique challenges to developing this contaminated site, Weaver said the municipal utility is “excited to see the project going forward as a visible example of local commitment to clean energy technology.”

Benefits of Redeveloping Brownfields

Redeveloping contaminated lands for renewable energy projects has become more common over the past several years. From California to New Jersey, countless landfills and brownfield sites lie abandoned—waiting to be transformed into a clean-energy-generating facility.

Converting contaminated sites into solar farms provide countless benefits. Serving as an alternative to previously undeveloped lands, redeveloping a brownfield site offers an economically-viable alternative to the cost of cleanup, reveals the Environmental Protection Agency (EPA). Utilizing existing roads, transmission infrastructure and utility hookups also reduces a solar facility’s overall costs.

Because they tend to be constructed near cities and towns, these facilities can create local jobs and help stimulate the economy. In fact, more than 100 cities in America predict they would each collect additional tax revenues between $205 and $500 million every year by re-purposing brownfield sites, according to the U.S. Conference of Mayors.

To encourage the revitalization of degraded lands, the EPA created the RE-Powering America’s Lands Initiative, which identifies the “renewable energy potential” of contaminated sites across the U.S. As of June 2014, the EPA facilitated the construction of over 709 megawatts of solar on brownfield sites through cleanup grants and other resources.

Contaminated Sites on Colorado’s Front Range

Across from the Buckley Air Force Base on Tower Road in Aurora, Colo., a city-owned 146-acre land parcel zoned for industrial uses sat vacant. “Portions of the property are contaminated with petroleum, solvents and other contaminants from historic activities at Buckley Air Force Base,” reveals the EPA. “Development of the property is significantly restricted.”

It was the perfect site for a community solar garden.

EPA Senior Environmentalist Tim Rehder specializes in the development of renewable energy projects on contaminated lands. Alongside researchers from the National Renewable Energy Laboratory, Rehder conducted a feasibility study on the Aurora site for the RE-Powering America’s Lands Initiative. The study concluded that 126 acres of the contaminated site could host a solar array—enough for 18 megawatts that could be developed in different stages.

marshall landfillA similar situation existed at the 160-acre Marshall Landfill site, three miles southeast of the City of Boulder. According to the EPA, water leached down through the inactive landfill in the early 1980s, collecting high levels of the cancer-causing contaminants benzene and trichloroethylene (TCE), in addition to barium, manganese and others. The property was designated a Superfund site in 1983.

“You have these landfills, the worst thing that can happen to them is they sit there and they erode over time,” said Paul Spencer, CEC Founder and CEO. “The best thing that can happen to them is to have some sort of operational facility on them to keep them up to date.”

The EPA worked with CEC to address liability concerns associated with construction, and CEC successfully developed a 498 kW community array in Aurora, and a 497 kW array in Boulder County.

“These two projects are excellent examples of how the RE-Powering program is helping put contaminated land back into productive use by bringing economic development, making good use of existing infrastructure and helping reduce pressure to develop nearby greenfields,” Rehder writes.

Other Unusable Properties

Brownfield sites aren’t the only undesirable lands. From utility substations to storage yards to gravel pits, CEC develops community solar arrays on property that can’t be used for other purposes.

“We have a very strong appetite for wastewater treatment sites and landfills because we can get a good lease and obtain property where neighbors aren’t an issue,” says CEC Land Manager Mark Zwieg. “Our goal is always to find pieces of land with trees or other buffer.”  The Eagle County Wastewater Treatment Plant—the site of CEC’s first community solar array in El Jebel, Colo.—didn’t appeal to many developers. In Breckenridge, the Sól Community Solar Array is built on a city-owned public works dump site while the photovoltaic panels in the Ullr Community Solar Array shimmer on top of a gravel pit with cement mixing operations.

Sometimes it’s not use of the property, but its location or development restrictions that make a site undesirable. The steeply-sloped parcel of land adjacent to the Garfield County Airport runway sat vacant before CEC and Holy Cross Energy built the 858 kW shared solar array.

CEC also seeks out oddly-shaped land parcels or compromised farmland before ultimately asking private landowners if they’re interested in leasing their property.

“The farmland we do go after, we’re very sensitive to agriculture needs,” Zwieg says. “We listen to the local farming community and try to work with them.” Oftentimes, portions of the field on which a solar array is constructed has issues undetectable to the naked eye—such as the land on which the Putney Community Solar Array is built, which contained drainage issues.

Some customers who own panels in CEC’s community solar gardens, such as Greg Gerloff of Breckenridge, appreciate the company’s desire to leave pristine land undisturbed, and turn existing unusable sites into a field of clean energy.

“I’m very pleased to learn that, in most cases, CEC is looking for property which cannot be used for other residential or commercial building,” Gerloff said.

Mid Valley Solar Array