Buried under a pile of trash at a northern New Hampshire landfill, discarded apple cores, eggshells and other bits of food are decomposing. This process generates a greenhouse gas much more potent than carbon dioxide – a gas that state utilities want to capture and use as fuel.
This so-called renewable natural gas comes from other resources, also: livestock farms generating agricultural waste and sewage treatment plants that treat human waste. Once purified, the gas is “fully interchangeable with conventional natural gas,” according to the US Department of Energy. As of last September, that had resulted in 548 landfill gas projects across the country, according to the Environmental Protection Agency.
New Hampshire’s gas utilities are looking to use renewable natural gas as the fuel of the future. Lawmakers have largely supported the efforts, despite environmental and financial concerns. Renewable natural gas could cost three times more than conventional natural gas.
Senate Bill 424 was defeated by two Senate committees with unanimous support and was passed by the Senate in a voice vote in March. The bill left the House Science, Technology and Energy Committee with five House lawmakers voting against and 15 in favor, and it is now up for a vote before the full the House with the recommendation of the committee to enact it.
The bill would allow natural gas companies to source up to 5% of their total gas from renewable natural gas, charging taxpayers the expense. It establishes a framework for doing so. Utilities should go through a bidding process to determine where they get the gas, and they should consult with the Department of Energy on the proposals they receive. Gas purchase contracts would be capped at 15 years, unless the Department of Energy grants special permission.
“The purpose of this Act is to encourage the purchase of renewable natural gas and investment in renewable natural gas infrastructure by gas utilities, provided that the Public Utilities Commission is satisfied that utility proposals are in the public interest,” the bill says.
New Hampshire’s two gas utilities agree with the goal and have both registered their support for SB 424. Unitil spokesman Alec O’Meara said the company views renewable natural gas as the cornerstone of its sustainability initiatives. “We see renewable natural gas as kind of the next step and what the next fuel source would be,” he said in an interview.
“That’s where things are heading. We believe this will be the cornerstone of carbon-free energy in the future,” he said.
Unitil lobbyist Kate Bourque had the same message for House lawmakers on environmental benefits, “including but not limited to potential carbon neutrality”.
But as the Legislature debates the future of renewable natural gas, at least two environmental groups in the state are concerned that environmental harms such as unwanted methane emissions or leaks will outweigh the benefits of the emerging technology.
Nick Krakoff, a staff attorney at the Conservation Law Foundation, said the bill’s safeguards were too weak to secure the promised environmental benefits.
“It gives utilities the opportunity to claim they are doing something green and good for the environment. But when you remove the layer, it won’t benefit the environment,” Krakoff said.
A specific problem, Krakoff said, is the lack of accounting for methane leaks, which can occur during processing or transportation and can quickly negate the climate benefits associated with renewable natural gas. And the greenhouse gas emissions from transporting the gas also need to be calculated, he said. The bill is currently silent on both. “When you weigh the impacts of greenhouse gases, you have to look at the big picture,” he said.
Krakoff’s biggest criticism of renewable natural gas is that it diverts attention and money away from cleaner alternatives, like heat pumps.
The Conservation Law Foundation has writing that gas is both expensive and limited; the organization argues that, for these reasons, it will do little to reduce emissions, but could be used to justify building and maintaining fossil fuel infrastructure.
“It’s just a way to avoid what really needs to be done to move 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 also part of the solution,” he said.
The Sierra Club opposes the bill, citing climate concerns about renewable natural gas extraction methods and its high cost.
“The bottom line is that it’s not going to reduce emissions (or) reduce costs for people,” said Catherine Corkery, chapter manager of the New Hampshire Sierra Club.
In a role currently before the Public Utilities Commission, Liberty has offered a 17-year contract to buy renewable natural gas from the Bethlehem landfill. According to the contract, the gas would be about three times more expensive than conventional natural gas. This case is currently on hold as the legislature decides whether the framework proposed in SB 424 will go into effect.
The Sierra Club also highlighted a 2013 study from the California Air Resources Board, California’s government air quality agency, which found that techniques to increase methane production from landfills also result in more uncaptured methane: 3.8 at 7.8 times more emissions enter the air compared to methane capture or extinguished combustion. The report includes a policy recommendation against new projects to turn landfill gas into energy.
But leaving methane in a closed landfill is also problematic. 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. According to Abichou, renewable natural gas is one way to incentivize landfills to do so.
“We tell people that we have to tackle methane as the fastest and most effective way to get climate change under control,” he said.