The article discusses the evolving role of gas networks in the transition towards green hydrogen as a sustainable energy carrier. Many countries are repurposing their gas infrastructure to transport alternative fuels like green hydrogen, which is produced sustainably through water electrolysis. Initiatives such as HyBlend in the US and UKRI's funding for large-scale projects aim to blend green hydrogen into existing gas networks, providing a cost-effective way to utilize surplus renewable energy and reduce carbon emissions. However, the article also highlights concerns about energy system security, as gas network malfunctions can lead to power outages, as seen in instances like the south-central United States blackout due to gas system issues. Research institutions are focusing on enhancing energy system resilience against disruptions, both internal and external, to ensure a reliable energy supply amidst challenges like extreme weather events and geopolitical tensions.