A small green gas tank sits in front of a white turbine.
The White Lake Gas Turbine in New Hampshire. Credit: Bob Gunderson / Flickr

This story originally appeared at the New Hampshire Bulletin.

Buried under a pile of trash in a landfill in northern New Hampshire, apple cores, eggshells, and other bits of discarded food are decomposing. That process generates a greenhouse gas many times more potent than carbon dioxide — a gas the state’s utilities want to capture and use as fuel.  

This so-called renewable natural gas comes from other sources, too: livestock operations generating agricultural waste and wastewater treatment plants that handle human waste. Once purified, the gas is “fully interchangeable with conventional natural gas,” according to the U.S. Department of Energy. As of last September, that had resulted in 548 landfill gas projects across the country, according to the Environmental Protection Agency.

Gas utilities in New Hampshire are looking to use renewable natural gas as a fuel of the future. Lawmakers have broadly supported the efforts, in spite of environmental and cost concerns. Renewable natural gas could cost three times as much as conventional natural gas. 

Senate Bill 424 was voted out of two Senate committees with unanimous support and passed the Senate floor on a voice vote in March. The bill left the House Science, Technology, and Energy Committee with five House lawmakers voting against it and 15 in its favor, and it is now up for a vote before the full House with the committee’s recommendation that it pass into law.

The bill would allow natural gas companies to procure up to 5% of their total gas from renewable natural gas, charging the expense to ratepayers. It establishes a framework for doing this. Utilities would have to go through a competitive bidding process to determine where they are getting the gas, and they’d have to consult with the Department of Energy on proposals they receive. Contracts for buying the gas would be capped at 15 years unless the Department of Energy granted a special approval.

“The purpose of this act is to encourage the procurement of renewable natural gas and investment in renewable natural gas infrastructure by gas utilities, provided that the Public Utilities Commission finds utility proposals to be in the public interest,” the bill states.

New Hampshire’s two gas utilities are on board with that goal, and both have registered their support for SB 424. Alec O’Meara, a spokesperson for Unitil, said the company views renewable natural gas as a cornerstone for its sustainability initiatives. “We see renewable natural gas as sort of the next step and what the next fuel source would be,” he said in an interview.

“This is where things are headed. We believe this is going to be a cornerstone to carbon-free energy going forward,” he said.

Unitil lobbyist Kate Bourque had the same message for House lawmakers about the environmental benefits, “including, but not limited to, potentially being carbon neutral.” 

But as the Legislature debates the future of renewable natural gas, at least two environmental groups in the state are concerned environmental harms such as unwanted methane emissions or leakages could outweigh the benefits of the emerging technology. 

Nick Krakoff, a staff attorney for the Conservation Law Foundation, said the guardrails in the bill are too weak to guarantee the promised environmental benefits.

“It gives utilities an opportunity to claim they’re doing something green and environmentally beneficial. But when you pull back the layer, it’s not going to be environmentally beneficial,” Krakoff said. 

One specific problem, Krakoff said, is a lack of accounting when it comes to methane leakages, which can occur during processing or transportation and can quickly cancel out the climate benefits associated with renewable natural gas. And the greenhouse gas emissions from transporting the gas must be calculated as well, he said. The bill is currently silent on both. “When you weigh the greenhouse gas impacts, you need to look at the whole picture,” he said.

Krakoff’s larger critique of renewable natural gas is that it’s diverting attention and money from cleaner alternatives, like heat pumps.

The Conservation Law Foundation has written that the gas is both costly and limited; the organization argues that, for those reasons, it will do little to lower emissions but could be used to justify building and maintaining fossil fuel infrastructure.

“It’s just a way of avoiding what really needs to be done to transition to clean energy,” Krakoff said.

O’Meara said Unitil is pursuing both heat pumps and renewable natural gas. “We believe that finding a way to decarbonize natural gas infrastructure is part of the solution as well,” he said.

The Sierra Club opposes the bill, citing climate concerns with extraction methods for renewable natural gas and the high cost.

“The nutshell is that it’s not going to deliver on lowering emissions (or) on lowering people’s costs,” said Catherine Corkery, chapter director of the New Hampshire Sierra Club.

In a docket currently before the Public Utilities Commission, Liberty proposed a 17-year contract to buy renewable natural gas procured from the Bethlehem landfill. Under the contract, the gas would be around three times as expensive as conventional natural gas. That docket is currently on hold, as the Legislature decides whether the framework proposed in SB 424 will go into effect.

The Sierra Club has also pointed to a 2013 study from the California Air Resources Board, the clean air government agency in California, which found that techniques to yield greater output of methane from landfills also result in more uncaptured methane: 3.8 to 7.8 times more emissions enter the air compared to capturing the methane or burning it off. The report includes a policy recommendation against new projects to turn landfill gas into energy.

But leaving methane in a closed landfill is problematic, too. Landfills need to optimize their collection system, said Dr. Tarek Abichou, a civil engineer who studies greenhouse gas emissions from landfills at Florida A&M University. In Abichou’s view, renewable natural gas is one way of encouraging landfills to do that.

“We are telling people we have to go after methane as the quickest, most effective way to get a handle on climate change,” he said.

New Hampshire Bulletin is part of States Newsroom, a network of news outlets supported by grants and a coalition of donors as a 501c(3) public charity. New Hampshire Bulletin maintains editorial independence. Contact Editor Dana Wormald for questions: info@newhampshirebulletin.com. Follow New Hampshire Bulletin on Facebook and Twitter.