Constellation, reputedly the country’s largest producer of carbon-free energy, has set an industry record for blending high concentrations of hydrogen with natural gas.

The test was conducted, in collaboration with Siemens Energy and EPRI, the Electric Power Research Institute, at Constellation’s Hillabee Generating Station, a 753 MW combined-cycle natural gas plant in central Alabama that began operating in 2010. The test showed that with only minor modifications, an existing natural gas plant of that age can safely operate on a blend of 38 % hydrogen, nearly doubling the previous blending record for similar generators. The test was conducted on 18 May on a Siemens Energy SGT6-6000G gas turbine.

The US Environmental Protection Agency recently released new guidelines aimed at reducing carbon emissions from the electric sector, citing hydrogen blending as a primary technology to help achieve the nation’s climate goals. The testing results at Hillabee demonstrate that hydrogen produced with clean energy can be an effective tool in meeting the agency’s goal.

“This test proved what we’ve suspected for years – that blending … hydrogen with natural gas can safely reduce emissions without major modifications to an existing plant that’s well over a decade old,” said Joe Dominguez, president and CEO of Constellation.

A 38 % blend rate would reduce Hillabee’s carbon emissions by approximately 270 000 metric tons annually, as calculated by EPA data. Significantly, nitrogen oxide (NOx) emissions did not increase during the test, confirming there was no negative impact to local air quality.

 “This project represents an important step in assessing the technical viability of hydrogen power generation,” said Neva Espinoza, EPRI’s vice president of Energy Supply and Low-Carbon Resources. “The ability to one day deploy hydrogen generation more broadly will rest on continued, collaborative R&D spanning hydrogen production, infrastructure development, and power generation applications.”

Constellation produces nearly 90 % of its energy from carbon-free sources and has a goal of achieving 100 % carbon-free electricity generation and a 100% reduction in operational emissions by 2040.