Energy project at Lebanon landfill moving forward
The project to convert methane gas to energy at the Lebanon landfill is on track to be operational next spring after 13 years of planning.
“It’s just so exciting that we’re finally moving forward with this,” said Marc Morgan, the city’s solid waste manager. “The implications are huge.”
The project will both generate revenue for the solid waste fund and reduce greenhouse gas emissions in New England by an estimated 3,500 tons each year.
Working with Liberty Utilities and Exeter-based Waldron Engineering and Construction, the City of Lebanon has executed contracts to convert the gas generated from organic waste at the landfill to electricity that will be redistributed to the electrical grid. The gas to energy project should be operational by spring next year, so long as supply chain slowdowns do not stall delivery of equipment.
The landfill generates about 350 standard cubic feet of landfill gas each minute. As microorganisms in an environment without oxygen break down organic matter, including food scraps, paper and cellulose, they release methane. The methane mixes with carbon dioxide as well as smaller amounts of sulfur compounds and other gasses to form landfill gas.
A foul, rotten smell once swept over Route 12A as the landfill gas ascended from the waste piles and spilled into the highway. In 2013 and 2015, the city installed a gas collection system and flare to burn away the odor. The flare converted the methane, an especially potent greenhouse gas, to carbon dioxide, which is significantly less polluting. The gas to energy system will utilize the preexisting gas collection project and flare, and it will emit no more greenhouse gas than the current system, city officials said.
“Instead of the gas being wasted — like it is right now, we’re just burning it — it’s displacing petroleum products,” Morgan said.
Burning landfill gas meets the standards for New Hampshire’s renewable energy portfolio. The city currently meets 20% of its municipal buildings’ energy needs with solar energy, and the gas to energy project will likely offset the other 80%. And there would still be renewable energy left over. If passed, New Hampshire Senate Bill 321 would enable the city to sell the power output and the renewable energy credits to institutions directly including nonprofits, schools or Lebanon Community Power. Alternatively, the city could enter a group net-metering arrangement with Liberty Utilities. Group net-metering allows a renewable energy generator to sell or share power with other customers of the same utility.
In all, the project will cost more than $5 million. City Manager Shaun Mulholland said that even conservative estimates show that it will be revenue positive during its first year, earning enough to cover the city’s bond payments and replenish the solid waste fund. The town is still negotiating the price arrangements, so the exact amounts are in flux.
Some environmental groups including the Sierra Club object to landfill gas to energy systems, arguing that they are not green because they still emit greenhouse gas and because the combustion of landfill gas is polluting. They also point out that, from an environmental standpoint, it is better to redirect organic waste away from landfills. City officials said that the city will continue its efforts to direct food scraps away from the landfill, and still anticipates enough landfill gas to fuel the system for years to come.
At the Lebanon landfill, a gas processing skid will clean the gas before it goes into five microturbines that will generate electricity.
“It’s very clean-burning,” Morgan said. “There’s some exhaust, but it’s a very clean fuel source.”
Clifton Below, Lebanon’s assistant mayor and the former chair of the Lebanon Energy Advisory Committee, has been a “champion of the project for a very long time,” Mulholland said.
Below sees the project as renewable because the energy it produces relies on biological material grown in our generation — our “current income” — rather than fossil fuels that took thousands of years to form.
“How is reducing waste not green and sustainable? We’re not wasting all the energy in the flare,” he said. “… We’re replacing fossil fuel — the stored capital of earth — and recovering waste.”
The project had several false starts. In 2011, Lebanon contracted Burlington-based company Carbon Harvest Energy to develop a gas to energy system, but the plan unraveled and the company eventually filed for bankruptcy. Below and other members of LEAC urged the city to take another look at the project, and a feasibility study showed it was economically viable.
Below is already looking ahead to new energy projects that will build on the city’s accomplishments at the landfill.
The system will produce excess heat, which could eventually be used by a nearby business, he said.
Out of an abundance of caution, Liberty Utilities also required the city to pay about half a million dollars to upgrade the local substation off of Poverty Lane to enable reverse power flows from the local distribution grid to the transition grid owned by the company, National Grid.The upgrade makes other distributed energy generation projects in Lebanon, Enfield and Plainfield more economically feasible, Below explained. With time, it might even help the area build a microgrid that would keep important businesses and services with electricity through a national disaster.
“It enhances the ability to be more locally self-reliant,” Below said.