Getting Hydrogen “Off the Grid”

Hydrogen Production 

Hydrogen can be produced through a variety of different methods characterised by a colour code.¹ This article sets to focus on green hydrogen, which is produced via electrolysis using electricity from renewable sources with zero CO2 emissions, such as wind and solar energy.

Electricity Transmission Network Upgrade

The electricity required for the production of green hydrogen will inevitably place pressure on the local and national grid. This naturally raises the question, how will the grid cope with the increase in demand? Firstly, emphasis must be placed on the term energy transition. Green hydrogen will form part of this transition as demand for it is expected to grow, meaning that more projects will start to come forward. To address the constraint challenges on the grid, in England and Wales National Grid is implementing reforms, with the Great Grid Upgrade being the largest overhaul of the grid in generations.  Through various projects,² National Grid is expanding grid capacity to connect 50GW of offshore wind by 2030.³ These projects will enable onshore infrastructure to cope with the increase in electricity produced from offshore wind farms for example, and also strengthen the grid to cope with transmission of the electricity required for electrolysis in green hydrogen production. 

Ofgem’s implementation of a new accelerated strategic transmission investment (“ASTI”) regulatory framework, offers a shortened lifecycle for energy infrastructure projects, which would typically take 11-13 years under the large onshore transmission investment regulatory framework.⁴ This allows for ASTI projects, such as those which form part of the Great Grid Upgrade, to be implemented in time to deliver the Government’s 2030 ambitions.

Interconnectors

Through its operation of six interconnectors, connecting the UK with France, The Netherlands, Belgium, Norway and Denmark, National Grid has the resilience to import electricity from overseas, enabling the sharing of large volumes of renewable energy where needed.

The Great Grid Upgrade projects will help to ensure that the onshore high voltage transmission network can transmit any additional electricity imported to locations where demand is generated, for example to support green hydrogen production. 

Location of Hydrogen Projects

Locating green hydrogen projects near existing renewable energy sources, such as wind and solar farms, would also enable the electricity to be fed directly into the water electrolysis process via private wire arrangements. This would bypass the need to run the electricity through the onshore grid and therefore reduce the pressure on the grid. In order to be classified as green, the electricity used in the water electrolysis process to produce hydrogen would need to be obtained from renewable energy sources. 

The plant could also be co-located by industry reliant on hydrogen production, such as ammonia production plants. Other uses for hydrogen include acting as a fuel source for industries which would not be able to rely on electricity, such as aviation and shipping, due to lengthy travel times and lack of charging ability. This would require establishment of infrastructure to offtake and transport the hydrogen to the end consumer.

The Use of Hydrogen in the Grid

Although rarely used, with less than a 1% chance of operation each year,⁵ National Grid has back-up generation secured for emergency purposes and is actively investing in hydrogen to be used for clean back-up generation, noting its quick dispatch qualities, to help further its vision for a fossil-free future. For example, following a trial period testing the capabilities and feasibility of hydrogen powered units as direct replacements for diesel generators, a unit at Deeside was found to have power capabilities of up to 100kW in continuous operation mode and up to 250kW for 45 minutes.⁶  

Conclusion

Hydrogen has a key role to play in the drive to net zero and decarbonisation of industries within the UK. Whilst the production of green hydrogen will inevitably increase the demand for renewable electricity, the UK transmission system owners have adopted methods to futureproof the UK high voltage transmission network; for example, National Grid’s its roll out of the Great Grid Upgrade and cross-border electricity interconnectors. The prospect of co-location and use of hydrogen as a back-up fuel source, further mitigates the impact on the grid and the reliance on fossil-fuel generators.

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[1] For more information on the hydrogen colour spectrum, please see: The hydrogen color spectrum (eversheds-sutherland.com)
[2] Source: The Great Grid Upgrade | Making our electricity fit for the future (nationalgrid.com)
[3] Source: National Grid seeking supply chain partners for Great Grid Upgrade Partnership | National Grid Group
[4] Source: Decision on accelerating onshore electricity transmission investment (ofgem.gov.uk)
[5] Source: https://www.nationalgrid.com/national-grid-call-out-industry-find-low-carbon-alternatives-back-diesel-generators
[6] For more information please see: National Grid goes carbon-free with hydrogen-[5]powered substation trial | National Grid Group