The hydrogen supply chain
Like methane, hydrogen is flammable and colourless. Unlike methane, it is biologically inert and burns to water, without emissions. One exciting application area for which hydrogen is being explored is the conversion of some gas networks to hydrogen. The goal is to decarbonise and provide energy solutions to current users of natural gas – including industry, commerce and domestic sectors.
Once these hydrogen network configurations exist, transportation networks in which the hydrogen passes through re-fuelling systems will become a reality. These can be used for displacing expensive, bottled storage of hydrogen or electrolysis at point of use. The idea is conceptually simple, and the technologies are largely ready and available today.
In domestic heating, the well-known inter-seasonal variations in energy demand between existing methane gas networks and electricity grids create multiple challenges. Within the UK, circa 30% of emissions are derived from such domestic heating. Equally, in locations such as the Netherlands, where existing methane supplies are at risk, hydrogen offers an elegant alternative to today’s energy systems.
Hydrogen at the point of use creates zero carbon emissions. This means using hydrogen in existing gas networks would reduce heating emissions to simply the by-product of water.
Production of hydrogen comes principally from two sources:
- Steam Methane Forming (SMR), which requires CCS (Carbon Capture and Storage) at scale in support of the process; and
- Electrolysis from renewable sources, with typical efficiencies of circa 80%. This process is scalable and can be switched on and off quickly in response to demand for energy. Surplus energy can be stored and distributed in the form of hydrogen.