Conformity assessment of domestic and commercial gas meters for usage with hydrogen enriched natural gas and pure hydrogen

Abstract

A considerable reduction in greenhouse gas emissions may be achieved if hydrogen is injected to the European gas networks, but accuracy of billing must be ensured. This paper presents the results for accuracy testing on seven domestic and one commercial gas meter. The domestic meters were calibrated by two different laboratories, at atmospheric pressure using various gases including hydrogen, methane and mixtures of hydrogen with methane. A third laboratory performed calibrations on a rotary gas meter with hydrogen and hydrogen/natural gas mixtures at two test pressures: 9 and 16 bar.For the domestic meter tests, consistent results were obtained from both facilities. Most meters tested met the accuracy requirements of the applicable standards. Whilst the error curves differed for each test gas, errors for hydrogen or hydrogen/methane blends were comparable with the other test gases. For the calibrations of the rotary gas meter, differences in the error curves between natural gas and the hydrogen/natural gas mixture were smaller than the measurement uncertainty of the test facility and therefore considered metrologically insignificant.