The role of hydrogen in achieving Net Zero – Report Summary

This is a House of Commons Committee report, with recommendations to government. The Government has two months to respond.

Author: Science and Technology Committee

Related inquiry: The role of hydrogen in achieving Net Zero

Date Published: 19 December 2022

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Hydrogen is a gas of high calorific value and when burned does not produce carbon dioxide, which is a harmful greenhouse gas. So, in principle hydrogen could play a role in decarbonising our economy and help reach Net Zero emissions by 2050, the UK’s legal target.

Pure hydrogen deposits on the planet are rare and limited, so the extent to which hydrogen can be produced without creating greenhouse gas emissions determines whether it can make a useful contribution to decarbonisation. Currently in the UK hydrogen is overwhelmingly produced from fossil-fuel intensive processes—so called “grey hydrogen”—grey hydrogen globally accounts for 2% of carbon emissions.

Hydrogen used in a Net Zero system will be either produced by processes which generate carbon dioxide but which is permanently extracted and stored (“blue hydrogen”), or through the use of renewable power to allow the electrolysis of water (“green hydrogen”).

Carbon capture, utilisation and storage (CCUS) is a technology that is currently not deployed at the large scale required to make a material contribution to our emissions reductions, nor are the economic and commercial conditions established for its mass use. This means that blue hydrogen cannot be relied on as a high-volume contribution to decarbonisation in the short- to medium-term.

The rapid expansion of renewable energy provides important possibilities for the mass production of green hydrogen in the future. But currently, we heard there is unmet need for renewable-sourced electricity to contribute directly to our power supplies as demand for electricity rises in both domestic and industrial settings.

The use of green electricity in producing, through electrolysing water, hydrogen for use as a fuel inevitably involves the loss of energy through the inefficiency of all such industrial processes. That said, we heard that if there was a large proportion of the electricity grid based on renewables, green hydrogen production might become very cheap during periods of low electricity consumption.

To make a large contribution to reducing greenhouse gas emissions in the UK, the production of hydrogen requires significant advances in the economic deployment of CCUS and/or the development of a renewable-to-hydrogen capacity. The timing of these is uncertain, and it would be unwise to assume that hydrogen can make a very large contribution to reducing UK greenhouse gas emissions in the short- to medium-term.

To maximise the future possibilities of using hydrogen to decarbonise the economy, clear commitments will be needed by the Government in the short- and medium-term to the development and deployment of carbon capture, usage and storage and renewable energy.

Using hydrogen to replace fossil fuels within our energy system would entail significant investment in the networks and infrastructure needed to distribute it around the country. For example, were hydrogen to replace petrol and diesel in passenger cars and heavy goods vehicles, an extensive and new network of hydrogen refuelling stations would be needed across the UK.

If hydrogen were to completely or substantially replace gas in domestic heating systems, a massive and costly programme of replacing boilers, meters and network infrastructure would likely be required.1

It seems likely that any future use of hydrogen will be limited rather than universal. It is likely to be best suited to applications or places which are:

  • Hard to electrify—such as some parts of the rail network;
  • Uses that do not require the creation of an extensive refuelling network—such as local bus services operating out of a fixed number of depots; and
  • Users who are adjacent to, or accessible to, places where hydrogen is produced, such as industrial clusters.

In addition, hydrogen has important potential uses as:

  • a means of energy storage; and
  • a source power for energy intensive industries like steel, glass and mineral production.

This limited—rather than universal—use of hydrogen should inform Government decisions. For example, we disagree with the Climate Change Committee’s recommendation that the Government should mandate new domestic boilers to be hydrogen-ready from 2025.

In our view multiple changes will be needed to the way we obtain, use and store energy if we are to reach Net Zero emissions by 2050. Hydrogen will have its place in this portfolio. But we do not believe that it will be the panacea to our problems that might sometimes be inferred from the hopes placed on it.

Essential questions remain to be answered as to how in future large quantities of hydrogen can be produced, distributed, and used in ways that are compatible with Net Zero and cost efficiency.

In the words of one of the witnesses to our inquiry, hydrogen is likely to be a “big niche” where it will play a major role in certain sectors of the economy, and be a “huge growth story” over the next 30 years, but “it will not be everything”.

To help it achieve that potential requires the Government to have a clear view of its practical deployment and to now turn the high-level Hydrogen Strategy into a set of operational decisions.