'I chase methane'

Marc Fetten calls himself “a recovering accountant” by trade, but these days he’s in the business of chasing things far smaller than numbers on a balance sheet.

 

“I chase really small things for a living,” Fetten told the Daniel Island Club audience at the Daniel Island Speaker’s Series on Sept. 17.

 

“Things you can’t see, things you can’t touch, things you can’t smell, but things you’re probably somewhat familiar with. I chase CO2 (carbon dioxide), and I chase methane.”

 

The Daniel Island resident founded GreenGas USA six years ago, a company that captures methane from organic waste streams – everything from farms to food processing plants – and converts it into energy in the form of renewable natural gas, known as RNG.

 

That gas is then injected into pipelines, displacing fossil fuels and cutting greenhouse emissions.

 

Processes like this, Fetten noted, have been happening in Europe for more than 30 years, but the U.S. has lagged behind.

 

Fetten illustrated just how potent these gases are with a simple demonstration: in the 100,000 cubic feet of the Daniel Island Club ballroom, the carbon dioxide present would fill 80 balloons.

 

The methane?

 

A single balloon. 

 

“Why do we care about CO2 and CH4 (methane)? Well, they’re considered greenhouse gases, and they are rumored to contribute to global warming,” he explained. “Methane, as a matter of fact, has a global warming potential that’s 85 times greater than CO2.”

 

It’s methane, he said, that often gets overlooked. Left alone, decomposing organic matter, from manure to vegetable waste, releases it into the atmosphere.

 

“If we did nothing at all, we would be producing methane,” Fetten said. “So what we do is instead of letting all that methane emit to the atmosphere, we capture it, and we make a fuel out of it.”

 

The numbers are staggering. From a single company’s waste stream, GreenGas can capture enough methane in one day to fill 1.6 million balloons. That’s half a billion balloons a year. “That’s enough methane to power every home in Daniel Island Park,” Fetten said.

 

The process reduces methane emissions by up to 85% compared to traditional waste management practices. Their current operations in 2025 have prevented 283,000 metric tons of CO2 from entering the atmosphere, and the company aims to reach 556,000 metric tons by 2026, he said.

 

GreenGas USA has grown from a startup backed by Fetten’s own home mortgage into a multi-project operation with 12 sites across the country and four in South Carolina.

 

“We work with customers that have decided that it’s better to use renewable natural gas than fossil natural gas,” he said.

 

The process goes beyond capturing methane. GreenGas has also developed technology to purify CO2 from waste streams, repurposing it for uses like refrigeration, dry ice, or beverage carbonation. 

 

Despite grim statistics surrounding global warming, Fetten rejects the narrative of doom.

 

“I don’t believe we’re on the verge of mass extinction,” he said. “I’m not going to sit here and tell you we’re in the middle of a climate crisis when it’s 75 degrees outside, we just watched the sunset, and it’s gorgeous.”

 

Instead, he closed with a message of gratitude and purpose.

 

“I’m thankful to leave a legacy of making significant positive environmental impacts at a scale that matters. To commit to a mission and purpose that leaves the planet in a better place than where I found it.”