R.I. Could Get its First Food-Scrap Digester

By TIM FAULKNER/ecoRI News staff

NORTH KINGSTOWN, R.I. — There’s a lot of green energy happening at Quonset Business Park. The 3,200-acre facility already has one of largest solar arrays in the state, at Toray Plastics, and currently several renewable-energy projects are moving ahead.

Compost facility. Permitting for the East Coast’s first food-scrap digester is expected to begin soon. NEO Energy LLC of Portsmouth, N.H., is scheduled to break ground in about six months on an 8-acre site. When finished by mid- to late-2014, it will turn food scrap into energy and fertilizer. Anthony Callendrello, NEO's chief operating officer, said the plant will process about 20,000 tons of food scrap annually. Letters of intent for accepting at least half that volume have already been reached with Rhode Island supermarkets and other food institutions, including a seafood processor at the Port of Quonset. No sewage or animal waste will be permitted.

“There is certainly plenty of food waste in Rhode Island," Callendrello said. "We’re confident that there is sufficient supply."

At a Sept. 10 meeting with members of the House Committee on the Environment and Natural Resources and the North Kingstown Town Council, Callendrello credited the state’s fixed-price energy program, known as distributed generation, for making the project doable. In 2012, anaerobic digesters were added to the list of qualifying energy sources for the DG program.

Callendrello also noted that Rhode Island has a better regulatory environment than Florida and Texas, two states where NEO has biomass facilities. “I think, on balance, it’s probably a better permitting atmosphere,” Callendrello said.

An artist’s rendering of the proposed food-scrap digester facility at Quonset Business Park. Food waste will generate up 500 kilowatts of electricity. (NEO Energy LLC)

An artist’s rendering of the proposed food-scrap digester facility at Quonset Business Park. Food waste will generate up 500 kilowatts of electricity. (NEO Energy LLC)

Food scrap, which accounts for about 12 percent of the U.S. waste stream, is a national problem. Diverting food from the waste stream will extend the life of the Central Landfill in Johnston, and perhaps create savings for cities, towns and businesses, as tipping fees, or the cost to drop food scrap at the proposed plant, could be free, Callendrello said.

A local food digester, he said, is “producing both a win for the environment and the energy situation in Rhode Island.” Currently, most of Rhode Island's electricity is generated by natural gas, less than 3 percent comes from renewable energy.

The industrial compost facility will control odors through a ventilation system that draws air into the building when doors are open. All the food scrap will be delivered by truck, and would be emptied indoors, according to Callendrello. The digester, which would draw methane gas from the food for fuel and energy, would be enclosed, containing any odors. “Everything is inside,” Callendrello said.

The primary revenue stream for the plant will be the sale of organic fertilizer. The proposed plant is expected to produce 1,000 tons a year. The fertilizer is low in phosphates and nitrogen and is ideally suited for turf farming and other agricultural uses.

“We want this project to be a showpiece for the region," Callendrello said. "To show that Rhode Island and the Quonset Development Corporation [are] really ahead of other communities in dealing with the food waste issue."

Solar energy. Several large solar-energy projects at Quonset are also helping diversify the state’s energy mix. The Toray Plastics solar array, which went online October 2011, has since been eclipsed in size by other projects in the state. Several proposed solar fields in the business park also will deliver more electricity.

A 2.4-megawatt solar array built on two former Naval warehouses is scheduled to go online by the end of the month. When completed, the $7 million West Davisville project will be tied for the largest rooftop solar project in New England, with the capacity to supply power for some 500 homes. It will be the largest solar project in the state, until the 3.7-megawatt Forbes Street landfill project in East Providence is completed in October.

Two half-megawatt solar projects are also in the works for Quonset: one on a former landfill; the second along a strip of land next to Davisville Road, one of the main thoroughfares at Quonset Business Park.

Toray Plastics is also launching a co-generation energy system, which captures heat from its facility to generate additional energy.

Steve King, managing director of the Quonset Development Corporation, noted that solar isn't the first choice for open land at Quonset. “We say, 'hold on, we’re here to make jobs.' Solar fields will create some jobs, but probably not as many as we like.”

Palmer Moore of Nexamp, the developer of business park's rooftop solar-energy system, noted that the project employed up to 50 workers during construction, but only requires routine maintainence when operational. But the project won't crowd out other businesses, Moore said.

“We are coexisting with an existing facility,” he said.

State inspectors were initially skeptical about a large rooftop project, he said, but eventually approved it, likely making it easier for future rooftop solar arrays in the state.