Heat Pumps or Hydrogen?
Some are touting the Hydrogen Economy as the way forwards, while others claim Heat Pumps are the future. Thus far at Siemens, I have only seen evidence to support the former. Anyone seen anything from industry to lend weight to the argument either way?
Recent Sunday Times Article on a Hydrogen trial for clean energy.
Emily Gosden, Energy Editor | 432 words.
Hundreds of homes in Scotland will be the first in the world to have their heating and cooking needs met by pure hydrogen after a £28 million trial won funding from the energy regulator. About 300 properties in the Levenmouth area of Fife will have hydrogen-burning boilers and cookers installed without charge and will be connected to a new pipeline network supplying them with 100 per cent “green” hydrogen. The gas will be produced through electrolysis, which will use electricity from a wind turbine to split water into hydrogen and oxygen. The first homes are expected to be connected in 2022, with the trial initially running for four and a half years. It is being run by SGN, the gas network company, which has been awarded £18 million funding from Ofgem and £7 million from the Scottish government. Decarbonising Britain’s homes presents a significant challenge, with about 80 per cent of homes using natural gas boilers that emit carbon dioxide, which causes global warming. Hydrogen has been touted as a potential solution because it burns cleanly. Although boilers and cookers would need to be replaced, hydrogen boilers could be used in conjunction with existing central heating systems. Proponents say that this would be less disruptive than switching to all-electric heating systems, such as heat pumps. It also could enable the continued use of existing gas networks, which would be beneficial to companies such as SGN, which distributes gas to 5.9 million homes and businesses in Scotland and the south of England. Angus McIntosh, 42, director of energy futures for SGN, said that the trial was an “exciting opportunity to revolutionise the way millions of people heat their homes”. He said that the high costs for the demonstration project included the fact that the boilers and cookers were “essentially having to be handmade for the purposes”, but added that significant cost reduction was expected if hydrogen was adopted at an industrial scale. The hydrogen will be produced using an existing seven-megawatt wind turbine in Levenmouth and a storage facility will be constructed to hold enough hydrogen to supply the three hundred homes for five days with no wind generation. As a fallback, the electrolysis could be run using power from the national grid. Mr McIntosh said that the trial would be voluntary and would be “as safe or safer” as using natural gas. The hydrogen will have the same odour as natural gas and will burn with a coloured flame in the cooker. In the event of a leak, a safety device should detect it and cut off the hydrogen to prevent it “ever being able to accumulate to an explosive level”.
Holdfast Training Services Trial Blog 
This is an interesting read. At Heathrow there was until recently 120mil quid allocated to projects to tackle the decarbonisation of heat across the airport (recent events obviously delayed this). The solutions touted by the design consultants were far and away electric heat pumps with combination of water course and ground coupled (Heathrow have number of boreholes in situ in prep for ground source already). Straight off the bat, the conversations of who to back (hydrogen or heat pumps) revolve mainly around the following issues:
– proximity to existing gas networks (off-grid locations are unlikely to benefit from hydrogen-driven boilers compared to electric heat pumps)
–
-appetite to retrain the workforce/technical expertise (heating engineers retrained as hydrogen boiler engineers is a far easier transition than introducing the expertise to install and commission electric driven heat pumps)
-longevity of infrastructure (the network exists already by and large to provide hydrogen supply to boilers and accounting for revision in building regs to stipulate more stringent fabric energy efficiency, may well be enough to supply existing homes ones hydrogen boilers come online. national grid to supply mass employment of heat pumps, not to mention us all buying a PHEV, perhaps not so)
Do you have an opinion yourself Harry?
“continued use of existing gas networks” sounds pretty straightforward but requires collective action, or the issue being forced on homeowners and/or businesses. Therefore, maybe late consumers will be able to make a choice on this but for the average home owner wanting to make a change (either complete or partial) there Hydrogen doesn’t really present a viable option at present. Whereas you can buy a heat pump to serve your new underfloor heating installation.
At this stage I would argue there is no clear future, and does there need to be a single panacea.
Hi Harry,
Two decent sources on the debate from the ‘Committee on Climate Change’:
CCC (2018) ‘Hydrogen in a low-carbon economy’, (November), pp. 1–128. Available at: http://www.theccc.org.uk/publications.
CCC (2019) ‘Net Zero Technical Report’, (May), pp. 1-269.
This is how I summarised it recently in a piece of writing.
‘Whilst the exact scale to which each technology will be employed in the future is unknown, the (CCC, 2019) have centred the majority of their heating decarbonisation scenarios for ZNC on the proliferation of heat pumps, in fact the core scenario recommended by the CCC for residential buildings is centred on the installation of heat pumps in 17 million homes across the UK by 2050. The ‘Hydrogen in a low carbon economy’ report by (CCC, 2018) validates the likely primacy of heat pumps within the building heating sector further by concluding that hydrogen boilers are likely to provide a ‘back-up role’ to satisfy peak demands whilst heat pumps provide the base load throughout the year due to the increasingly low carbon electricity produced by the grid.’
Therefore it seems as though heat pumps are currently earmarked to provide the lions share (baseload) of the residential sectors heating. The key advantage of hydrogen boilers is clearly the ability to provide large quantitites of heat on demand (like a traditional gas fired boiler) and as Al points out it will be easier to retrain the workforce to specialise in hydrogen boilers. Heat pumps work best when supplying low grade heat continously (this requires houses designed in such a way to exploit this low grade heat – underfloor heating etc.). You can get ‘High Temperature Heat Pumps’ providing ‘high grade’ heat (70°C using technology such as two stage vapour compression cycles) however the cycle efficiency is compromised.
I did hear that a new 500 house estate is being designed to incorporate three phase electrical supplies to each house in order to provide power for electric car charging and heat pumps. With what you’ve provided from the times article on a ‘hydrogen trial for clean energy’ it seems both of these technologies are being advanced simultaneously.
I think the bottom line is it cannot yet be determined which of the technologies will gain the ascendancy (Al’s list emphasises the complex and fluid factors at play) but that both will have a part to play towards decarbonising the building sector. I imagine it is a case of rolling out both heat pump and hydrogen programmes and evaluating the success/performance in an attempt to actively inform our overall strategy..
Nice short comment from me as i’m sure your eyes are bleeding if you’ve gotten this far. Some excellent discussion points above – I would just add the following (non technical) thought, in an attempt to contextualise the implementation of heating de-carbonisation.
I don’t think I’d be way off the mark by saying that the direction of travel (at least in the first iterations) will be dictated by governmental strategy, given that the initial roll out will be heavily govt subsidised.
It is very easy for us, as complete nerds, to think of this of a purely engineering problem. The solution with the greatest efficacy wins the day, right? More likely – the decision will probably be politically driven, specifically which solution will create the most jobs. HS2 is not even close to being a panacea for solving Britains rail capacity issues, but as a 20 year, major CAPEX project, it guarantees a job for 1000s. The cold, hard reality is that job creation and low unemployment statistics win elections, engineering brilliance doesn’t.
Scott, i’ll pick you up, it certainly isn’t easy for me to be a complete nerd, it’s given me more grey hairs and aged me 10 years so far, and not even begun thesis yet (jk Jim).
In terms of job creation and the fiscal policy behind an engineering judgement, have a look at Energiesprong UK. It’s an idea pioneered by the Scandinavians I think (when they’re not designing our mid-range flatpack furniture). The methodology uses ‘future cost savings on energy bills’ to pay for the retrofit of energy efficiency measures to housing in the present, to make it net-zero energy (still relies on grid electricity so cannot claim to be zero carbon).
Given that about 80% of the homes that will stand in 2050 have already been built (and many to pre-net zero carbon BRs, since the legislation hasnt yet been enshrined, it’s only off of the back of advice from QUANGOs that many practices are being taken up), the Energiesprong way, or something like it, could have legs. The occupier sees no change to their energy bills, the lowered energy costs go to repayment of retrofit measures.
Lastly, this is not to be confused with the table of energy efficient retrofit suggestions that is produced along with a building EPCs, that is rarely specific and never works towards a zero-energy/carbon. But that’s another convo as I am sure your eyes are bleeding.
Interesting point Al, similar to the projection in Uninhabitable Earth: Climate change to cost the Global Economy ~$8 trillion by 2050 if we continue on current trajectory, however if we invest ~$2 trillion by 2030 we’ll avoid that cost.