No matter which solutions are ultimately put into practice to decarbonise energy, they will need to provide a substitute for natural gas, on which more than 80 percent of households depend on for heat, and which provides around 40 percent of electricity generation.

However, ensuring security of supply will remain critical as the transition progresses – and this is where hydrogen can form part of a whole systems approach,in addition to being a direct substitute for gasin heating households.It’s not just about the potential of the technology to decarbonise heat; there are regions and parts of the manufacturing sector that cannot feasibly decarbonise without hydrogen.

Hydrogen networks will also need to replicate the 99.99 percent reliability of gas transmission, a challenge most acute when planning for winter peaks: gas satisfies most winter demand, providing six times more energy than electricity and nearly two-thirds of domestic energy demand in peak conditions.

Geography, geology, network connections and housing patterns will determine both what is possible and what is optimal when it comes to decisions about hydrogen. As far as the “megatrends” of demand management go, the Future Energy Scenarios produced by the Electricity System Operator provide some long-term indicators.

Two of the scenarios envisage a large role for hydrogen: whereas System Transformation majors on “blue” hydrogen through steam methane reformers with carbon capture and storage, Leading The Ways scenarioassumes quick decisions leading to strong subsidies and support for “green” hydrogen production through electrolysis.

The means of production are significant for interoperability.Blue hydrogen needs natural gas as a feedstock (as would be needed for any legacy gas network): green hydrogen needs electricity as a feedstock (which is also needed in the electricity network). A guiding mind would be essential, to oversee and manage the transition as a ‘third’ new energy vector came into being.

Given the massive shift these transitionsrepresent, security of supply in both commodity (“is there enough gas?”) and capability (“can it flow onto the national transmission system and into local distribution networks?”) need analysis to ensure that the industry can continue to deliver to consumers when and where needed. This extends to the commercial capability of any future decarbonised system, and ensuring that the gas system operator has sufficient balancing tools to manage supply shocks in the system.

Both production and storage will have to be phased and realistic in scale. In publishing its sixth carbon budget, the Climate Change Committee recommendeda ‘Blue Hydrogen Bridge’ approach. This would entail supplementing electrolysis with scalable production from routes involving CCS to enable sufficient low-carbon hydrogen production to meet a fuller range of emerging demands.

The CCC’s proposal highlighted the criticality of how to manage the transition and crossover when moving to hydrogen, requiring new assets which provide headroom for the transfer -and existing assets with sufficient resilience. The requirements will vary around the country, depending on timing of demand moves and energy efficiency measures.

Ultimately though, security of supply goes beyond the technical capacity of the industry to provide enough of a particular commodity and get it to the right place:public policies and corporate strategies need to align. There is a commercial chain reaction of use cases creating demand for hydrogen,triggering further investment and consequently lower costs, greater consumer acceptance and the momentum needed to build sustainable supply chains. Once established, there is also the question of developing the right operational tools, asset investment and commercial rules to deliver a truly resilient system and operate it effectively.