Converting the supply
The UK wants to reduce carbon emissions by 80% of 1990 levels by 2050. A recent Westminster Forum debate discussed what role hydrogen will play in future supply. Ines Nastali reports.
A recurring theme during the future of the gas network event, organised by the Westminster Forum, was the use of hydrogen to supply energy to the UK grid. Dan Sadler is Programme Director of H21 – a project that wants to replace natural gas with hydrogen and turn Leeds into the UK’s hydrogen centre after a feasibility study was done in the city in 2016. The city is keen to push hydrogen as it is close to both Teesside with its existing hydrogen infrastructure and the salt beds north of Hull. For H21, Sadler currently travels the world to find partners to get involved and look at foreign concepts of hydrogen conversion. Currently, the project’s main partner is Norwegian energy provider Equinor (previously Statoil until March 2018).
It is estimated that the H21 North of England project would avoid up to 18m tonnes CO₂ per annum and generate 85TWh, with a conversion taking place between 2028 and 2035.
While concrete data on the new project is not yet available, the plan for the Leeds blueprint sees the need for an investment of around £2bln to pay for the conversion. But, ‘if the H21 Leeds City Gate project was funded using the current UK regulatory business plan it would have negligible impact on customers’ total gas bills,’ it is further stated.
Costs would go towards the steam methane reformer, which is used to extract the hydrogen from methane, for maintenance of salt caverns to store it, and the conversion of appliances for domestic and industrial users.
Improving the infrastructure
The project would rely on the Health and Safety Executive replacement programme for the 200-year-old iron pipes to decrease hydrogen leakage. Since 2002, polyethylene pipes have replaced these, as part of the Iron Mains Replacement Programme (IMRP) that will finish in 2032. ‘If the existing metallic distribution mains were used to transport hydrogen without the upgrade being undertaken by the IMRP, it is reasonable to assume that there would be an increase in leakage levels,’ the Leeds City Gate report states.
‘This is due to hydrogen having a low density, at only one eighth the density of methane. This is not necessarily an increased safety issue from today’s current position when compared directly to the risk associated with natural gas, but is certainly a commercial problem.’
Attendees at the Westminster Forum wondered how the hydrogen would be supplied and why steam methane conversion was the preferred option over hydrolysis. According to the project report, using hydrolysis would be too expensive as an alkaline electrolyser costs around £700,000 and a polymer electrolyte membrane electrolyser costs around £1m per 1MWe. ‘Assuming electricity was available as required, 400 2.6MW electrolysers would be needed to meet the design point hydrogen supply of 1,025MW,’ the report states.
Securing the supply
Energy security will not be secured as the system decarbonises, warned Jim Watson, Director of the UK Energy Research Centre. Energy security solely depends on how energy is supplied. The meeting’s debate therefore also touched on carbon capture and storage systems (CCS), a second factor the H21 project relies on.
Watson voiced concern about future efforts to establish a CCS infrastructure in the UK. The government pulled funding for it in 2015, but reigniting commitment with the launch of the Clean Growth Strategy in 2017 (read more on CCS in the UK in Materials World February 2018). He said, ‘I have worked on CCS for a long time and I don’t think capacity can be upscaled and that the supplied hydrogen has been produced in a low carbon way’. While Sadler admitted that the low carbons supply would be challenging, he bases his optimism on the well-explored storage locations in the North Sea.
The forum concluded that in the end, ‘it is the networks’ responsibility to integrate natural gas into the supply chain, not the suppliers’, Chris Walters, Managing Consultant at Gas Strategies said. Adding that ‘investment into technology and infrastructure is needed for future low carbon electricity production’. At the same time, governmental policy makers need to get involved early as they currently always play catch-up with technology.