HyGreenNet

Transitioning from fossil fuels to non-carbon alternatives is an important step toward achieving carbon neutrality. The European Commission’s roadmap for a climate-neutral Europe by 2050 prioritizes developing a hydrogen economy through electrolysis. However, the cost of developing hydrogen transportation networks poses challenges for renewable hydrogen adoption in decarbonization of sectors. To address this, blending hydrogen into existing natural gas networks has emerged as a cost-effective option for transporting hydrogen to various end-use applications.
Despite hydrogen’s benefits as a clean energy carrier, uncertainties remain regarding its blend tolerances within current gas infrastructure. Further research, development efforts, and pilot projects are necessary to understand hydrogen’s impact. Safety concerns related to blended gas transport—such as material compatibility, pipeline leakage, gas quality, and fluid flow—must be addressed. A safe, efficient, and sustainable infrastructure connecting production and consumption is essential for hydrogen utilization. While the results of completed projects in this area suggest that hydrogen blends up to 20% by volume are safe, operational thresholds may vary based on network composition, topology, and end-user requirements. Thus, operational experience and ongoing research are critical for successful hydrogen blending projects.
To prepare for the integration of hydrogen into the Irish gas network, Gas Networks Ireland partnered with University College Dublin (UCD) Energy Institute. Their joint effort aimed to demonstrate the safe and reliable operation of residential end-user devices across a range of hydrogen concentrations (2% to 20%).
The project evaluated the safety and stability of gas supply and device operation as hydrogen concentrations increased. To facilitate the integration of hydrogen into the gas network, Gas Networks Ireland has conducted a comprehensive series of tests to assess network readiness. In collaboration with University College Dublin (UCD) Energy Institute, the Network Innovation Centre developed three distinct project phases. Phases One and Two have been completed, and their results are available on Gas Networks Ireland’s website. Currently, Phase Three (HyGreenNet) focuses on the distribution network. It involves testing medium and low operational pressures, with a specific focus on safety, leakage, material compatibility studies, and detailed performance analysis of commercial package boilers.