Switch to hydrogen could secure long-term future of UK gas system
May 30, 2018
A new project looks to leverage the strengths and existing assets of the UK’s natural gas industry to pave the way to greater hydrogen penetration in the energy mix, writes Jeremy Bowden
A pioneering project in northwest England is aiming to become a key staging post in the transition from natural gas to hydrogen in the UK’s energy mix.
Plans have been put forward for a major hydrogen plant, production from which would replace natural gas supply for industrial and residential consumers.
The scheme appears to have the backing of all levels of government and if successful could be the first of many, which would provide a far cheaper way to decarbonise heating systems than electrification. It would also have the added benefit of using existing pipeline infrastructure that criss-cross the country.
Heating and cooling is responsible for 50% of energy that is consumed around the world, compared to just 30% for transportation and less than 20% for power generation. This means that curtailing fossil fuel use for heating and cooling is critical for the reduction of carbon emissions, a core environmental objective for most European countries. Wind, solar and other renewables have made good progress in decarbonising the power mix and electric vehicles (EVs) are now penetrating deeper into the transport sector. But there has so far been little progress on decarbonising heat.
Most environmentalists favour the electrification of heating in industry and private homes, but it is becoming increasingly apparent that replacing gas boilers and expanding the power system to cope with peak winter demand would be too expensive.
In the UK, estimates have been put at GBP15-20,000 (US$20-27,000) per home. It would also be necessary to instal six times the current generating capacity (about 55 GWx6) to meet peak winter heating demand in the UK if the system was entirely electrified, according to a recent National Grid report. This is important, as peak demand tends to come mid-winter when renewables are low, so it is even harder to do in a zero-carbon electric system. (It would be tricky enough to meet additional demand from EVs if they take off as expected).
Using hydrogen to store the energy in a similar way to methane appears to be the main decarbonisation alternative to electrification for heating, and that favoured by many established energy players – partly because it makes use of existing up, mid and downstream assets.
There are two main ways of producing hydrogen. The first and cheapest (in terms of energy required) is from natural gas using a process known as steam methane reforming (or auto-thermal reforming), with the carbon monoxide/dioxide by-product captured centrally and sequestrated (carbon capture and storage – CCS).
The other way is through electrolysis, using surplus renewable energy in order to avoid carbon emissions altogether.
Graham Bennett, DNV’s VP of business development for the UK and West Africa, said he anticipated that most of the hydrogen in the UK would come from natural gas. “We think most will come from methane via steam methane reformers dotted around the coast, with the carbon dioxide produced going into CCS,” he said. “Currently we have 26.5 million houses burning gas – if you convert the hydrogen you have a single source of carbon dioxide which is easier to capture. The network of hydrogen plants would be linked to offshore CCS. It’s cheap because it uses existing infrastructure.”
“Hydrogen’s energy density is a third that of methane – so you would be using about the same amount of methane as today or slightly more. You’d convert the methane to hydrogen at the plants and feed it into the grid – most of the metal pipes have already been replaced so no issue of migration of the hydrogen through steel.”
However, he said hydrogen may not suit all countries. “I know our colleagues in the Netherlands are looking at [hydrogen], but every country is different ... In Norway for example, they see electrification as the only option. But that’s because they have plenty of cheap hydro, and they have never had a gas grid. In big European economies with extensive gas grids the cheapest form of energy transition may be hydrogen, as electrification is likely to prove prohibitively expensive.”
The proposed hydrogen plant in the UK, dubbed HyDeploy, would use methane as feedstock. Its location has not yet been chosen, but it is likely to be near industrial users in Ellesmere Port or Runcorn. The developer, Cadent (the new name for the private owner of the gas grid, formerly National Grid Gas Distribution), then hopes to build a network of pipes to supply 10 industrial users, as well as mixing it with natural gas in the residential system serving Cheshire, Merseyside and Greater Manchester.
Cadent believes as much as 20% hydrogen can be added without harming domestic boilers and cooking equipment. Research is under way at Keele University to understand how to make hydrogen use safer at higher concentrations.
Cadent then captures the waste carbon monoxide and carbon dioxide and pumps it to the depleted Hamilton gas field under the Irish Sea. The cost of decommissioning can be avoided if the fields and pipelines are reused for storing carbon. Cadent said trials would start in the early 2020s, and that, longer term, the network could also be used to supply hydrogen as a transport fuel.
In early May the company released a report estimating the cost of the first phase of the project at GBP900 million (US$1.2 billion). Cadent’s director of safety and strategy, Simon Fairman, said the company would need to “clear some hurdles” before the project could proceed. “We need a favourable government policy mechanism for carbon capture, usage and storage,” he said.
The UK’s new heating decarbonisation policy is due to be announced by the government soon, and many observers say it needs CCS to be workable. A recent report on hydrogen in UK heating by the Oxford Institute of Energy Studies (OIES), the UK must sort something out quickly because “it has a particularly rigorous framework for achieving decarbonisation, underpinned by the Climate Change Act 2008 (CCA).” This sets a binding target of 80% reduction in greenhouse gas (GHG) emissions (compared to 1990) by 2050, and “provides for the establishment of a trajectory to that goal based on five-year ‘carbon budgets’.”
Other parts of the UK exploring hydrogen for heating include Leeds, where Northern Gas Networks (NGN) is aiming to convert the existing natural gas supply.
The HyDeploy project has received the backing of the region’s two metropolitan mayors – Andy Burnham and Steve Rotheram, who called the project “visionary”.
It also appears to have central government support, with UK Energy and Clean Growth Minister Claire Perry commenting: “Clean, green and safe hydrogen has an exciting role to play in powering the UK and Cadent’s investment is a significant step towards this energy source living up to its potential.”
The Institute of Mechanical Engineers (IMechE) is also behind the scheme and has called on the government to “step up” its support for the use of hydrogen across all energy sectors. It said hydrogen could act as a much-needed source of storage (as oil and gas do today) and a “conduit for connecting the energy system together”.
Encouragement for CCS in particular would certainly boost enthusiasm among potential investors. They are likely to be waiting to hear something more concrete (or otherwise) from the upcoming heating decarbonisation policy announcement before deciding whether to get fully behind the scheme.
A project that could lead the way to a lower carbon heating system, and one that plays on the strengths and existing assets of the industry, surely deserves some state support to spur it on.