Hydrogen

As an energy carrier, hydrogen can play a significant role in energy security, carbon reduction and economic growth. It will be the crucial element of any future energy system.

Hydrogen is invisible, odourless and non-toxic, and has been used safely for many decades in a wide range of applications, including the food, metal, glass and chemical industries. The global hydrogen industry is well established and produces 50 million tonnes of hydrogen per year.

The following make hydrogen an excellent fuel for a range of applications:

  • Zero to near-zero carbon footprint depending on the method of production;
  • Range of production methods, leading to fuel flexibility and energy security benefits (see below);
  • Available as a waste stream for capture from a variety of industrial processes (including carbon capture and storage);
  • Safe to produce, store, transport and use in fuel cells and internal combustion engines; and
  • Able to act as an energy buffer, thus helping to overcome renewable intermittency issues and deliver grid balancing.
  • Hydrogen Production

    Hydrogen can be delivered from a range of fossil fuels. Currently, majority is produced via natural gas reforming. The ability to generate hydrogen from renewable sources, including wind and solar energy, exists today, and offers a zero carbon footprint. Pre-combustion technology for the capture of CO2 has added value as a method for hydrogen production as it directly generates hydrogen from a range of fuels such as biomass, waste, coal and natural gas. This will result in large amount of carbon-free hydrogen. Other routes to hydrogen are expected to be commercially developed; one example is via the utilisation of nuclear heat.

    It is expected that no single hydrogen production method will dominate future markets. All production methods could be a part of the future hydrogen energy portfolio; this will provide greater flexibility and resilience to the system than would be the case with any single method.

    Hydrogen Storage

    Hydrogen can be stored:

  • At pressure – in cylinders typically at 200 or 350 bar. For stationary purposes, hydrogen pressure vessels are used. Where larger volume of storage is required, underground storage in salt caverns is also practised.
  • As a liquid – hydrogen can be stored at -253 C.
  • In a solid form – where hydrogen reacts with metals to form various forms of solid metal hydride, which can then release the hydrogen under controlled conditions on demand.
  • Hydrogen is currently delivered in gaseous form using tube trailers or cylinders, and in liquid form in cryogenic liquid hydrogen tankers; pipelines are used to a very limited extent.

    Hydrogen Infrastructure

    The widespread deployment of hydrogen powered vehicles will require an extensive refuelling network. The development of such a network will take time and occur in phases. The initial stages are already in place, with refuelling facilities at a number of locations supporting captured fleets of vehicles. In selected areas, the establishment of several refuelling stations has resulted in the formation of clusters, which allow vehicles to extend their range beyond that afforded by single sites. Over time, and as further clusters develop, a comprehensive infrastructure will evolve. Whilst the bulk of investment in hydrogen refuelling infrastructure can be expected to be made by the private sector, financial assistance for the first stations from Government will be important to help kick-start the process.