The University of Sheffield has announced a new collaboration with ITM power for the advancement of the renewable hydrogen sector and green hydrogen. The proposal for a new Gigafactory and investment into National Hydrogen Research will prove important to the decarbonisation of the energy sector as well as create jobs within the Sheffield Innovation district. But what is green hydrogen and what role can this play in the energy transition?

The many hues of hydrogen

Most of the hydrogen currently produced as a fuel is classed either as ‘brown’, ‘black’ or ‘grey’. These are extracted from fossil fuels, releasing vast amounts of greenhouse gas in the process. Another form, ‘blue’ hydrogen, adopts these methods but uses carbon capture technology to allay the emissions. Whilst seeming to provide a solution, blue hydrogen remains highly controversial due to uncertainties around storage longevity and actual carbon neutrality. 

Alternative methods of procuring hydrogen include tapping into underground stores via fracking, named as ‘white’ hydrogen. This carries with it a host of associated environmental problems; induced earthquake stimulation and the destruction of natural environments. 

These methods of hydrogen production are highly problematic. That’s why ITM Power and the University of Sheffield are working to produce green hydrogen, produced without the use of fossil fuels. 

Green is the new black

Green hydrogen is produced through the electrolysis of water using renewable energy from sources including solar and wind. This can then be used as a chemical fuel within a fuel cell. The best part is that the only by-product produced is more water! 

Using green hydrogen as a fuel would fill a gap in the renewables supply. Whilst renewable electricity is crucial for the energy transition to a zero carbon world, some technologies are not fit for electrification and would benefit from using a sustainable gaseous fuel. For example, green hydrogen is ideal for the transport sector – especially long haul flights and ships that are too large to rely on rechargeable batteries – and would cut refuelling time for hydrogen cell cars. 

There has been some discussion at governmental level that hydrogen could play a role in heating homes. With current infrastructure, hydrogen could be added into the gas supply at low levels to cut emissions from heating. Unfortunately, this is limited as a move to 100% hydrogen in the gas network would require a major upgrade to energy infrastructure and renewable energy production would also need a significant boost.

Hydrogen even has the potential to act as a battery for renewable energy. As we often hear ‘the sun doesn’t shine all the time’ or ‘the wind doesn’t always blow’. But sometimes we do have a lot of renewable energy in the system. Excess renewable energy could, in theory, be ‘stored’ as hydrogen and then used when needed, increasing the reliability of a weather dependent energy supply.

Green hydrogen can also be used to ‘green up’ hydrogen fuelled industries including fertiliser and steel production.

Great! Why don’t we already run on hydrogen?

Green hydrogen does offer a glimpse into a decarbonised fuel future but as with many large scale projects, it is not yet plain sailing. As our fuel infrastructure has been built to distribute fossil fuels, it is as yet unsuitable for the replacement with hydrogen. Hydrogen requires higher pressurisation than natural gases and has a tendency to make metal brittle requiring a specialist hydrogen-suitable distribution network. 

More research into this as a potential fuel source will ease this transition and with an overhaul of the infrastructure system required as the fuel sector moves away from fossil fuels, this can be viewed as an inevitability rather than hindrance.The research undertaken by the University of Sheffield and ITM can play a vital role in making green hydrogen a viable renewable energy source.

Green hydrogen is also currently quite pricey, projected to be around 4 times more expensive than its grey and brown counterparts, consequently accounting for low use at <1% of the hydrogen supply. This is in part due to the high price of electrolysers, used to pass the electricity through water, thus splitting hydrogen from oxygen. With investment and further research, the price of electrolyser construction is expected to decrease, making green hydrogen a more viable resource.

An exciting opportunity…

Green hydrogen offers an exciting new opportunity for research and could play a crucial role in our journey to net zero emissions. Regarding governmental decisions on a zero carbon future, green hydrogen will inform the energy transition. As a result, this research collaboration between the University of Sheffield and ITM Power into green hydrogen will place the University of Sheffield at the forefront of the energy transition for years to come.