Constellation Energy has set an industry record for blending high concentrations of hydrogen with natural gas, further evidence that hydrogen can be an effective tool to lower greenhouse gas emissions.

Working with Siemens Energy and EPRI, the hydrogen blending test was conducted at Constellation’s Hillabee Generating Station, a three-unit, 753-megawatt 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 blending test occurred 18 May at Hillabee on a Siemens Energy SGT6-6000G gas turbine.

The 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.

A 38% blend rate would reduce Hillabee’s carbon emissions by approximately 270,000 metric tons annually, the equivalent of taking more than 60,000 passenger cars off the road, based on EPA data. Experts from Siemens Energy and EPRI collaborated with Constellation on the fuel blending tests.

NO_x emissions did not increase during this blending test, confirming there was no negative impact to local air quality. Hillabee is fitted with Selective Catalytic Reduction (SCR) technology, which significantly reduces NO_x emissions.

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. The company will use the results from this test to inform its plans for transitioning its natural gas facilities to carbon-free technology in the coming years.