Waste-to-renewable energy could save NYC wastewater facilities costs

The nonprofit group Energy Vision has released a new report assessing the benefits of applying innovations to wastewater resource recovery facilities across New York City.

Entitled “Gotham Gas Goes Green,” the new report finds that upgrading New York City’s wastewater plants could produce clean energy, slash greenhouse gas emissions, divert food waste from landfills and generates savings and revenue for the city.

The independent report assesses the benefits of applying innovations piloted at Newtown Creek, the city’s largest wastewater plant, to more of its 14 wastewater resource recovery facilities (WRRFs).

Operated by the city’s Department of Environmental Protection, these WRRFs have a total of 75 anaerobic digesters which break down sewage sludge and capture the methane biogases emitted as it decomposes. Historically, WRRFs have flared this methane as a by-product of the digester process. But it’s a potentially valuable energy resource.

To realize that potential, DEP and its project partners upgraded the Newtown Creek plant. Food waste collected and supplied by Waste Management now augments the sewage sludge the digesters process, boosting methane production. A new facility built on site by National Grid then refines this methane into renewable natural gas (RNG) fuel. RNG is chemically similar to fossil gas and usable in all the ways fossil gas is used, but has much lower GHG emissions. Newtown Creek RNG will be injected into National Grid’s pipelines and used to heat over 5,000 Brooklyn homes.

This waste-to-renewable energy model has big potential benefits. If more of DEP’s 14 WRRFs adopted it, they could produce enough RNG to power the city’s entire fleet of heavy-duty trucks, the report finds. This would cut GHG emissions from city operations 15%, generate up to $80 million a year in cost savings or new revenue, and process 30% of New York’s 1.2 million tons of food waste annually, keeping it out of landfills. Using RNG fuel in city trucks or buses could displace 25 million gallons of diesel fuel, avoiding pollution and health damage from diesel exhaust.

“New York has a golden opportunity here,” said Matt Tomich, president of Energy Vision. “Generous tax credits and incentives in the Inflation Reduction Act could help finance WRRF upgrades. DEP is seeking partners to put WRRF biogas to use, and private capital is interested in renewable energy projects. Between diverting food waste from landfills, capturing WRRF methane, and replacing fossil natural gas, the climate benefits of these projects are immense.”