Can hydrogen and CCS save one another?
Carbon capture and storage (CCS) and the ‘hydrogen economy’ have long been touted as essential tools in decarbonising our energy system, yet they have always seemed to be 10 years away. CCS in the UK received a major blow in 2015 when the Government announced that it was cancelling a £1bn demonstration programme for power plants equipped with carbon capture technologies. Hydrogen fuel cell electric vehicles were originally thought to be the mostly likely driver of a new hydrogen economy, but due to recent dramatic cost reductions and range increases from battery-electric light vehicles, hydrogen-powered cars seem to be losing the race in the low emissions transport market.
Despite this bleak picture for CCS and hydrogen sectors, they have been thrown a potential lifeline by proposals to decarbonise industry and domestic heating systems using hydrogen that is produced by the steam reformation of natural gas.
A report by the H21 Leeds City Gate project suggests that converting the entire natural gas network of Leeds from methane to hydrogen is feasible. This process requires all domestic appliances that run on methane, like boilers, to be replaced with hydrogen-fuelled equivalents. The authors estimate that this entire transformation would cost £2bn, which sounds like a lot, but is likely to be less disruptive and costly than alternative paths to decarbonising heating systems, such as district heating, heat pumps or electrification.
Just last week, another major UK hydrogen project was proposed. Cadent and Progressive Energy are launching a plan to convert methane-powered heavy industry in the Liverpool-Manchester region to hydrogen. They also propose to blend a small percentage of hydrogen with the local domestic natural gas system.
As the steam methane reformation (SMR) process produces carbon dioxide in large quantities as a by-product, both projects propose to combine hydrogen production with carbon capture and storage. H21 hopes to be the beginning of a CCS ‘hub’ at Teesside and the carbon dioxide from this project would be transported via pipeline to a saline aquifer under the North Sea where it would remain indefinitely. The Liverpool-Manchester plan, meanwhile, would store the carbon dioxide in a soon-to-be depleted and uneconomic oil and gas reservoir under the Irish Sea.
But why go to all this bother? Is there not a better, cleaner way to produce hydrogen that does not prop up the oil and gas industry? Well, the main alternative method of producing hydrogen is electrolysis, or ‘power-to-gas’, but this is currently more expensive than SMR in most places and cost reductions will depend not just on technological development, but also on the country being awash with excess low carbon electricity, something we are a long way from as a nation.
Although the UK’s North Sea oil and gas production is in decline, few talk about ‘peak oil’ as being a major concern anymore. The Oxford University economist Dieter Helm, in his new book Burn Out: the Endgame for Fossil Fuels, suggests reducing demand for fossil fuels could mean that low oil and gas prices could be the new norm. SMR production of hydrogen, even when combined with CCS, could therefore be a cost effective way of transitioning to an economy at least partially fuelled by hydrogen. In the future, SMR hydrogen production could be replaced by electrolysis powered by renewable sources of electricity, or even thermo-splitting of water using heat from advanced nuclear fission or fusion.
There have been stories in the media recently expressing concerns about the amount of extra electricity capacity that would be required if there is a wholesale shift towards electric cars. In reality, with smart technology to ensure cars are predominately charged at times of low demand elsewhere in the system, electric vehicles will only add a few per cent to overall demand. The total energy required would be small compared to what would be needed to heat our homes and power our heavy industry. Electrification of heat and heavy industry would be hugely challenging and expensive. This is another reason why hydrogen produced from natural gas would be a beneficial addition to our energy system.
Neither hydrogen nor CCS are silver bullets for the decarbonisation of heat and industry and challenges lie ahead. The processes of hydrogen production and carbon capture need to become more efficient and less costly, the feasibility of a 100 per cent hydrogen network needs to be demonstrated, and long term storage facilities may be necessary to smooth out differences in seasonal demand. But both technologies are widely seen as key tools in developing a complete low carbon energy system. The UK, with a fully developed natural gas pipeline network and numerous potential offshore carbon dioxide storage sites, is perhaps the country most suited to be a pioneer in this field.