Performance testing of gas flow meters with renewable energy gases

As Europe moves towards renewable energy sources, the characteristics of energy gases being transported in European gas infrastructure will change significantly. These changes will impact the accuracy of measuring instruments that are used for billing and custody transfer. Currently, gas flow meters are often calibrated with air as medium to represent natural gas. However, little is known about the transferability to specific energy gases using these calibrations. Measurement standards for hydrogen and hydrogen-enriched natural gas flow are missing, to test the performance of the current state-of-the-art metering technology. In this work, we investigate the performance of a thermal mass flow meter and rotary flow meter using relevant energy gases, including mixtures, as part of the EMPIR project Metrology for Decarbonising the Gas Grid. We use a reference piston prover traceable to the primary measurement standards of VSL. We review the results in light of the possibilities for calibration with surrogate gases.