Powering a campus from landfill methane

By Madailein Hart

Deep inside the University of New Hampshire’s co-generation natural gas power plant, David Bowley, the Utility System Manager for the plant, shouts over the sounds of turbines spinning, steam springing out of pipes, and many types of gases moving through chambers. Workers in masks, hard hats, thick gloves, and safety goggles maneuver all around, as the innovative plant delivers energy to the college campus in a way that adds much less carbon dioxide into the environment.

Methane, carbon dioxide, and sulfate are just some of the gases coming in from a landfill 12.5 miles away in order to keep this plant, and the school it is built on, up and running. Natural gas was the largest source—about 32%—of U.S. electricity generation in 2017, and most other grids are powered by it, or coal, or nuclear. But UNH runs mainly on methane. A university in California is also exploring the creation of such a plant, but plans have not been finalized

Prior to 2005, UNH purchased its energy from an outside source to power a heating plant on campus. In 2006, a plan was created to expand the heating plant to make it into a co-generation, eco-friendly power plant. In 2009, the power plant stopped using distillate oil and added a pipeline from the Rochester landfill that delivered cleaned garbage gasses.

“I was skeptical at first,” said Scott Lindquist, the Operations C manager at the university. “I have been on the energy side of things for 15 years, and I’ve been at the university for 30 years, and at the time I had never heard anything like it.”

Lindquist says his cooling team and the power plant have a great relationship with one another, mostly because the plant has made cooling for the university practically free using a closed water loop, reusing the water that has run through the heating and cooling plants dozens of times,

The most common gas used in this process is methane, a carbon neutral fuel, meaning that it puts out almost no carbon emissions. The reason UNH created this was to achieve their Climate Action Goal, which was to reduce their green footprint by 50% by 2020.

A 2008 study, called The Carbon Footprint of Best Conserving Americans Is Still Double Global Average, done by students at MIT, says that “average annual carbon dioxide emissions per person, they found, was 20 metric tons, compared to a world average of four tons.” Carbon emissions have a direct impact on our climate, and many Americans have been trying to find ways to conserve energy by driving cars less, turning off the lights more, or shopping locally.

The way the plant is running, Bowley is confident that he and his team will reach that goal. The pipeline that comes in from Rochester to Durham runs parallel to the Spaulding Turnpike, past the university’s horticulture farm, crosses Main Street, goes behind the new stadium, travels behind the railroad tracks and then lands in the power plant on UNH’s campus. Even though everyone who works in or around the power plant calls the system of pipes “The Pipeline,” the official name it was given is the Eco-Line.

Bowley explained that the process of turning landfill gas into clean energy is a long one. First, the gas must travel through a pipeline that goes from Rochester to Durham. When the gas lands at the plant, impure gases are filtered out. These are gases such as hydrogen sulfide, sulfur dioxide, and carbon dioxide.

The gas runs through an activated carbon bed that traps sulfide, then moves to another activated carbon bed that takes out the volatile organic compounds, or VOC. This term can be interchangeably used with non-methane organic compounds, or NMOC, when referring to landfill gas.

Finally, the gases go through a molecular sieve containing aluminum sulfide that separates the carbon from the methane. “The concept is very much like an everyday sieve you may use to strain things in your kitchen,” says Bowley, “think pouring pasta and water into a colander, or sieve; the smaller molecules fall through the sieve into the sink, the larger left behind.”

Even though the carbon dioxide, a well-known greenhouse gas, gets released back into the atmosphere, it is 22 times better for the environment than the carbon dioxide that would be created in the landfill, explains Bowley. The methane, another well-known greenhouse gas, gets put to work in the power plant.

The gas is used to heat, cool, and give electricity to UNH. The entire process of cleaning the gas takes about ten seconds.

“The effect of controlling the emission of one ton of methane is equivalent to preventing the emissions of 28-36 tons of CO2,” explains Bowley.

Before the pipeline was built, all these gasses were flared at the landfill, which was contributing to the growing problems of global warming. Since the gas has been put to good use at the university, it has been better for the environment, and the people of Rochester smell less of the landfill in their town.

“All the efforts made over the years are part of the larger goals of efficacy, low cost, and sustainability,” adds Matthew O’Keefe, the Director of Energy and Utilities

According to preliminary data collected by the Washington Post, New Hampshire’s main source of energy comes from nuclear power, which makes up 56% of how the state gets its energy. Natural gas comes in second, but only makes up a quarter of the energy. The remaining 19% of energy comes from a combination of solar, hydro, and coal plants. For the whole country, natural gas plants made up 34% of the electricity throughout the US. This, however, was mainly due to increases in fracking and the amount of natural gases as a result led to more natural gas plants.

UNH also has a numerous amount of security measures for the power plant, and O’Keefe prides himself and his team in all the precautions taken and disasters avoided.

“Obviously though, there are things you can’t plan on,” O’Keefe says.

The plant is run twenty-four hours a day, seven days a week, all year round. Two people, no matter the time, weather, or holiday, are always at the plant monitoring its electricity and heating status. If the heat or power fails, there are always backup generators ready to go. If the backup generators fail, the university can contact a high-voltage electrician at any time. In O’Keefe’s thirteen years of working for the university’s power plant, the longest blackout was just under five hours.

Some people, like Jennifer Andrews, the Sustainability Project Director at UNH, believe that UNH has created a unique problem for itself. While many schools are trying to get students to be more aware of what can be recycled or composted, UNH needs all the food waste it can get in the landfill to power the plant while also encouraging students to be more aware. Andrews says that in order to balance making students conscious of their food intake while also sending natural items to the landfill, UNH has installed a “Take Less, Waste Less” program.

Bowley had a different take on this issue. He explained that UNH has a contract with the landfill company that will last another ten years.

“Even if the landfill shuts down tomorrow,” Bowley said, “we would still have enough gas from the landfill to fulfill the contract.”

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