Constellation Energy Corp. and Siemens Energy AG said they had set a new record for blending natural gas with hydrogen at a combined-cycle gas plant, nearly doubling the previous record.

Constellation’s Alexander City, AL-based 753-MW natural gas-fired Hillabee Generating Station operated during a test this month with minor modifications using a blend of 38% hydrogen. Hillabee, which began operations in 2009, is equipped with a Siemens SGT6-6000G turbine. 

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

Siemens and Electric Power Research Institute experts joined...