Injection of hydrogen into existing natural gas grids, either partially or as a complete conversion, could decarbonise heat and take advantage of the inherent flexibility that gas grids provide in a low-carbon future. However, hydrogen injection is not straightforward due to the differing properties of the gases and the need for low-cost, low-carbon hydrogen supply chains. In this study, an up-to-date assessment of the opportunities and challenges for hydrogen injection is provided. Through value chain optimisation, the outlook for hydrogen injection is considered in the context of a national energy system with a high reliance on natural gas. The optimisation captures the operational details of hydrogen injection and gas grid flexibility, whilst also modelling the wider context, including interactions with the electricity system and delivery of energy from primary resource to end-use. It is found that energy systems are ready for partial hydrogen injection now and that relatively low feed-in tariffs (£20–50/MWh) could incentivise it. Partial hydrogen injection could provide a stepping stone for developing a hydrogen infrastructure but large scale decarbonisation of gas grids requires complete conversion to hydrogen. Whether this solution is preferable to electrification in the long term will depend on the value of the gas grid linepack flexibility and the costs of expanding electricity infrastructure.

将氢气注入现有的天然气网格中（部分或全部转化）可以使热量脱碳，并利用天然气网格在低碳未来中提供的固有灵活性。然而，由于气体的不同特性以及对低成本，低碳氢供应链的需求，氢的注入并不简单。在这项研究中，提供了对注氢的机遇和挑战的最新评估。通过优化价值链，可以在高度依赖天然气的国家能源系统的背景下考虑注氢的前景。该优化捕获了氢气注入和气网灵活性的操作细节，同时还对更广泛的环境进行了建模，包括与电力系统的相互作用以及从主要资源到最终用途的能源输送。研究发现，能源系统现在已准备好部分注入氢，相对较低的上网电价（20-50英镑/兆瓦时）可能会激励它。部分注氢可以为开发氢基础设施提供垫脚石，但是气网的大规模脱碳需要完全转化为氢。从长远来看，该解决方案是否比电气化更可取，将取决于燃气电网线组灵活性的价值以及扩展电力基础设施的成本。部分注入氢气可以为开发氢气基础设施提供垫脚石，但是气网的大规模脱碳需要完全转化为氢气。从长远来看，该解决方案是否比电气化更可取，将取决于燃气电网线组灵活性的价值以及扩展电力基础设施的成本。部分注入氢气可以为开发氢气基础设施提供垫脚石，但是气网的大规模脱碳需要完全转化为氢气。从长远来看，该解决方案是否比电气化更可取，将取决于燃气电网线组灵活性的价值以及扩展电力基础设施的成本。