Project Summary
SIF Innovation Challenge
This project looks to address the challenge of preparing for net zero power systems using novel ways to reliably support low stability systems. Green hydrogen production is a low stability system in that the production is reliable on the weather (wind/solar) and/or constraints in the electricity network. This makes it very hard to predict the alignment of production and use of hydrogen.
Improvements in the efficiency of hydrogen production will maximise the hydrogen created within periods of high renewable energy availability.
Energy Network Innovation
Hydrogen is looking to be transported within the gas networks to decarbonise the UK, hydrogen production is currently focussed on the industrial clusters and there will be limited access to hydrogen during the transition to decarbonise operational sites, especially those not situated on the hydrogen backbone. On the NTS many compression systems are planned to be replaced to enable them to meet emissions targets, an alternative approach is to capture emissions whilst we transition them to utilise hydrogen at a lower cost. This is required sooner than the full network transition to hydrogen and therefore onsite production could assist. In order to supply hydrogen to these sites in an economical manner renewably powered electrolysers are being considered.
Partner Experience and Capability
National Grid Gas (GT&M) and UKPN are considering the opportunity of electrolyser interactions with the energy networks. GT&M are also managing the integration of the systems into operational sites. Anglian Water are a key stakeholder in the production of hydrogen from electrolysis and it is key to understand the impact on their network as well as our own.
Ceres are experts in solid-oxide electrolyser systems and Alfa Laval have many years of experience in deploying heat recovery solutions, these are the two critical technologies for our system development. Cardiff University have expertise in gas turbine development and digital systems, their role will be to provide insight into optimising the system through data and support our understanding of the likely emissions of burning hydrogen and hydrogen blends, this is important when designing emissions capture systems. HydroGenus are supporting the project on the commercial implications of the proposed system.
Potential Users and Needs
The focus of this work is on the gas transmission system but the solutions developed in this project could be utilised across the UK where waste heat is available to improve the efficiency of hydrogen production.
Innovation Justification
Problem
This project looks to improve the efficiency of green hydrogen production utilising waste heat produced by the high-pressure gas network which is not currently utilised. Green hydrogen production can be expensive and inefficient leading to criticism of its capability against electrification; however, it is a far more efficient method for storing renewable energy. In improving the efficiency of green hydrogen production, we can maximise the conversion of electricity to hydrogen and greatly improve the business case and costs of hydrogen.
Innovation
The application of waste heat recovery on the national transmission system (NTS) gas turbine systems has not previously been undertaken and its integration with solid-oxide electrolysis systems has not been considered; but could provide an optimised hydrogen source for many applications. The Ceres solid-oxide electrolysers are relatively new systems which are looking to demonstrate capability in 2023 alongside the Discovery and Alpha phase of this project, to enable full demonstration of the system in 2024.
Knowledge Gaps
Little work has been undertaken on the use of gas turbine waste heat for electrolysis and therefore there are many knowledge gaps to fill, requiring a cross functional team of experts: our partners. We will need to consider not only the equipment but the integration to an operational site and optimisation through data. The work packages described in Discovery enable us to quickly determine the suitability of this proposal.
Economic and Sustainability Value
The alternative solution to this project is to deploy PEM electrolyser systems which are less efficient than their solid-oxide counterparts, leading to less hydrogen for every unit of electricity utilised and increasing the cost of the produced energy source. At present the waste heat from the onsite compression systems is not utilised and therefore development of this capability could also provide energy for other applications such as hydrogen storage.
Funding Options
The system proposed is novel in its approach and relatively low in technology readiness levels therefore it is not ready to be deployed as business-as-usual (BAU). The BAU alternative available for deployment is limited by efficiency and therefore the business case for deployment is harder to justify. SIF funding will enable this technology to be accelerated into use in connection with our 24 compressor stations. In the case that hydrogen is not utilised in the compression system this solution will enable capture of emissions and heat whilst providing hydrogen for other users in the local area.
Project Benefits
The Discovery phase will develop the business case and the cost/benefit analysis for this project. The benefits that we propose to track are as follows:
Financial - Electrolyser efficiency vs alternative on market PEM system
This will consider the energy input into the electrolyser and the output hydrogen. Consideration will be made for periods throughout the year when waste heat may not be available and the impact of this on the efficiency of the overall system.
Further to this a consideration for the approximate cost of the equipment and operation of the facility will be made against that of a more traditional electrolyser. The cost of the system vs the efficiency will then be considered over a set period of time to ensure that the system cost does not override any efficiency benefits seen. In order to ensure this calculation is as realistic as possible hydrogen production periods will utilise an example year of weather in the demonstration location and the same year of compressor utilisation. Working with UKPN and the innovative electrolyser connection project we will ensure alignment between the benefits cases.
The calculation will be as follows for both the baseline and method:
(Cost of electricity in per annum + system cost + ongoing cost per annum*) / Volume of hydrogen produced per annum = relative hydrogen cost
*Ongoing cost per annum - this could include maintenance, water, land requirements etc...
Environmental - System Emissions
This will consider the potential reduction in emissions in deploying this system and quantify this against current emissions. Consideration of this against emissions targets and the potential to deploy this system instead of replacing assets will be made. Benefits could be seen during the beta phase, once the demonstration is operational, however most benefits will occur once the system has been deployed across multiple operational sites. We believe this could be through the Project Union timeline of between 2026 and the early 2030s for the gas transmission network.
