Hydrogen could provide cheapest option for decarbonisation of heating system 

NW England hydrogen plant to use natural gas as feedstock, depleted fields for CCS

A major hydrogen plant designed to replace natural gas supply to industry and residential consumers in the northwest of England has come a step closer and appears to have backing from all levels of government. If successful, it could be the first of many, providing a far cheaper means of decarbonising heating systems than electrification.

Best option for big job

Heating and cooling is responsible for 50% of energy used globally, compared to just 30% for transportation and less than 20% for power generation, so reducing fossil fuel use here is critical to reducing carbon emissions – which still appears to be the goal of most European nations. While wind, solar and other renewables are making good progress in decarbonising the power sector, and electric cars have the potential to deal with transport, there has been little progress so far on decarbonising heat.

Most environmentalists favour electrification of heating in industry businesses 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 just be too expensive. In the UK, estimates have been £15-20,000 per home, plus installing six times the current generating capacity (about 55GWx6) to meet peak winter heating demand in the UK if the system was entirely electrified, according to a recent National Grid report – and 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 will be tricky enough meeting additional demand from electric vehicles, 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). The other way is through electrolysis, using surplus renewable energy in order to avoid carbon emissions altogether.

In a recent interview, Graham Bennett, DNV’s VP Business Development for UK and West Africa, said he expected 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 CO2 produced going into carbon capture and storage. Currently we have 26.5 million houses burning gas – if you convert the hydrogen you have a single source of CO2 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.”

HyDeploy

The proposed northwest hydrogen plant, dubbed HyDeploy, would use methane as feedstock. Its location has not yet been chosen but it’s 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 ten 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 underway 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 says 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 Cadent released a report estimating the first phase of the project at £900 million. 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.”

The UK’s new heating decarbonisation policy is expected to be announced by the Government soon, and many observers say it needs CCS to work.  According to a recent report on hydrogen in UK heating from the Oxford Institute of Energy Studies1 (which is well worth a read), 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)”, which sets a binding target of 80% reduction in greenhouse 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.

Universally popular?

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 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 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 says hydrogen can 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, who may 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 that plays on the strengths and existing assets of the industry, surely deserves some state support to get it going.

 

1.P8 https://www.oxfordenergy.org/wpcms/wp-content/uploads/2018/05/Decarbonisation-of-heat-and-the-role-of-green-gas%E2%80%99-in-the-United-Kingdom-NG-128.pdf

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