From 1816 to the present: The Stirling engine provides clean energy solutions

Based on a design invented and patented almost 207 years ago by Robert Stirling, Qnergy’s free piston Stirling engine is revolutionizing the capture of one of the most harmful pollutants out there, methane, and turning it into electricity.

The Ogden, Utah-based company took an engine first used to pump water into a quarry in 1818, retrofitted it with patented technology that is now deployed in a dozen oil fields and gas in eastern Utah, with more operating in Wyoming and 500 that are. scattered in the Marcellus formation in the United States, one of the largest natural gas fields in the world.

“There is a high concentration of methane in natural gas,” said Steve Maughan, Qnergy’s vice president of engineering.

In fact, natural gas is made up of between 70% and 90% methane, which, after carbon dioxide, is the second most prevalent greenhouse gas, accounting for 20% of global emissions, according to the US Environmental Protection Agency.

Coupled with Qnergy’s compressed air pneumatics system, the Stirling generator can take what would be harmful methane emissions at gas well sites and turn them into harmless compressed air. These power generators can also transform emissions from landfills and pig farms.

Methane mitigation is especially important in the oil and gas industry, as the Biden administration is restricting emissions and issuing fines to producers who emit at certain levels.

Kristin Murphy, Deseret News

Simplicity in action

The beauty of Qnergy’s Free Piston Stirling Engine is that it uses no friction to convert an energy source into electricity and has no external combustion, Maughan said.

This allows the generator to be essentially maintenance free, without a routine annual inspection.

“They can run 24/7 for a year,” he said.

“In a combustion engine, every six weeks you have to change the oil,” he said. “There is no reason to oil the (Stirling) engine.”

The engines are designed for 80,000 hours of continuous operation and, to date, the worldwide deployment of these have accumulated 10 million hours of engine operation.

The company has one of its generators at a remote location in Utah’s Nine Mile Canyon, where it is used to power the energy needed to provide cathodic protection for natural gas pipelines.

Cathodic protection prevents corrosion in buried metal pipes, storage tanks and oil well casings.

In the case of Nine Mile Canyon, the generator is producing direct current electricity to provide this protection, eliminating the need for a power pole.

Kristin Murphy, Deseret News

From Nine Mile Canyon to the Idaho National Laboratory

A Qnergy engineer teamed up with project leader Yasir Arafat at the Idaho National Laboratory to develop the right type of Stirling engine to power MARVEL, a sedan-sized nuclear microreactor that could come online next year coming.

At a media event earlier this year, Arafat explained the importance of MARVEL.

“The way I think about the world is that 50% of the world’s population lives on 1% of this earth’s footprint. With microreactors, you can make uninhabitable places habitable, and again, you can refine the water, get energy. … It can give people opportunities to live. We’re looking at Mars and other planets to colonize, but on Earth we have a lot of uninhabitable places that we can open up.”

Qnergy has one of its generators in a remote location in Alaska and has worked with the National Oceanic and Atmospheric Administration to install power to run weather stations.

Graham said that while other companies are starting to enter the field, they remain the leader. Even though it’s only a two-week production run, their order backlog reaches as far as August.

The company employs a group of engineers across all disciplines and has a business development office on the MIT campus.

“There’s nobody else doing what we’re doing,” Graham said.

Kristin Murphy, Deseret News