In a groundbreaking field test conducted in Erftstadt, near Cologne, Germany, TÜV Rheinland, GVG Rhein-Erft, and Rheinische Netzgesellschaft (RNG) have been investigating the impact of adding 20% hydrogen to the existing gas network since October.
The aim of this experiment is to assess the feasibility and effects of increasing the hydrogen blend in the gas grid, which was previously limited to a maximum of 10% hydrogen by German legislation.
After the conclusion of the heating period, the partners reviewed the interim results and found that all connected gas consumption devices operated flawlessly. Homeowners and businesses were able to use their gas appliances without any issues, and no modifications or conversions were required to accommodate the altered gas composition. The integration of a higher hydrogen concentration had no adverse effects on the regular operations of the gas network.
The field test, which involves 100 households from the Niederberg, Borr, and Friesheim districts, is set to continue until the end of December. The chosen districts are ideal for this type of trial since the gas network, approximately 9 km long, was constructed in 2007.
TÜV Rheinland conducted the pioneering field test on an L-gas network, which differs from the H-gas network in terms of gas composition and origin. L-gas, supplied to western Germany, contains a lower energy content (80-87% methane) and is more cost-effective compared to H-gas, which has a higher energy content (87-99% methane) and is costlier.
The collaborative effort of TÜV Rheinland, GVG Rhein-Erft, and RNG involved gradually introducing hydrogen into the test area. Initially, a 10% hydrogen blend was mixed with natural gas, and after four weeks, the proportion was incrementally increased to 15%. Since October 2022, the gas network has been successfully operating with a 20% hydrogen admixture.
To ensure the compatibility of each gas-consuming device in the project area, a pre-test was conducted using a gas mixture containing 23% hydrogen. This meticulous approach allowed the project manager, Mr. Michael Thys (GVG), to verify the suitability of all gas appliances within the test region.
Moving forward, TÜV Rheinland plans to expand its testing scope to examine the technical possibilities of introducing a hydrogen blend of up to 30% in suitable gas networks. This continued exploration of higher hydrogen concentrations in the gas grid demonstrates the commitment to advancing the utilization of hydrogen as a cleaner energy source.