There is a war being fought between those who think hydrogen is the answer to our net zero transition problems, and those who think it will make those same problems worse. As always, the truth lies somewhere in the middle. It is this middle ground we will try and explore in this blog post - so make a coffee, get comfortable and when you're ready, lets go....!
Another week has passed in the battle of hydrogen, and it's been a strange strange one. The week started with the US Office of Energy Efficiency and Renewable Energy posting about the virtues of using offshore wind energy to produce clean hydrogen. To illustrate the simplicity of using hydrogen for heating homes across America, a simple graphic was used illustrating the end to end energy chain - from generating clean electricity to using it in a home.
It all looks very simple and sensible. Offshore wind turbines produce clean electricity which is used to power electrolysers. These electrolysers take simple, clean water and break the water compounds into their constituent elements - hydrogen and oxygen. This clean, zero carbon hydrogen is then stored in big tanks before being piped to homes - fantastic!
This US dream takes a strange turn 2 days later days when the same Office of Energy Efficiency and Renewable tweeted a correction, stating 'We apologize for using this outdated graphic – our analysts caught it, as did many of you. While we could use OSW [off shore wind] to produce clean hydrogen, none of our roadmaps consider home heating a viable use for H2. We expect the more feasible use is decarbonizing heavy industry'
So what is going on? If we can displace carbon intensive natural gas that heats our homes with clean hydrogen, why would we not? In this case the hydrogen is produced from 100% renewable electricity and utilises the existing gas infrastructure we have spent decades building. So why would the USA not have heating with hydrogen on any of their road maps? Well the 'corrected' graphic by Milton Miller on Twitter (find it here) sums up the point that those who oppose the use of hydrogen make very neatly - if we produce clean electricity, why bother with all the hydrogen stuff?
Milton Miller's modified graphic on how to use clean offshore wind power - which was accompanied with the comment 'fixed it for you'.......
Cut out the middleman the argument goes, and use the electricity networks to transport the renewable energy directly to our homes and businesses.
Expert View
Half way through the week we had a couple more public interventions in the form of opinion pieces in 'Utility Week' magazine, the first titled 'Expert View'. This column argued that heat pumps cost £13,000 to install in a typical UK dwelling, while a hydrogen installed boiler would only cost £1,500, therefore hydrogen heating should be part of the mix of solutions for low carbon heating. This expert viewpoint belongs to David Watson, who is head of energy transition at Cadent - a UK natural gas distribution company. With a degree in business and law, and a career spanning regulation and strategy all spent at gas companies, some are questioning just how 'expert' this opinion is.
The second opinion piece in the same magazine came from Jon Butterworth, the 40 year titan of the gas industry and CEO of the National Gas, the new name for the old National Gas Transmission and Metering business that National Grid sold to a consortium of investors last week as part of the National Grid's pivot away from gas to electricity.
Jon makes a passionate case for hydrogen being part of the mix for getting to net zero. Some will discount Jon's arguments as part of a campaign of companies with huge vested interests in gas infrastructure - but this is a simplistic argument that needs to be resisted in order to fully understand the issues we are faced with. Jon asks a very pointed and valid question - "if we are going to stop sending 400 million of cubic meters of gas into the UK and Ireland what are we going to do instead"? A good question indeed.
National Gas's 'Future Grid' hydrogen test facility in Cumbria
What Problem Are We Trying to Solve?
Opponents of hydrogen will argue (with good reason) that the only proponents of using hydrogen are those with heavily vested interests - and point to articles like those above as the lone voices of hydrogen support. It is true that fully 'independent' voices supporting widespread use of hydrogen are very rare (and independent research even hard to find as a peer reviewed paper by Jan Rosnow from the Regulatory Assistance Project finds). We do however need to explore the problem that hydrogen is trying to solve to really understand where hydrogen can in, so back to Jon's question - if we stop using natural gas, what are we going to do?
Scale of The Problem
The UK is uniquely exposed to natural gas as a consequence of our history - with access to lots of cheap natural gas from the North Sea, we have one of the most comprehensive natural gas transmission and distribution networks in the world. The result of this history means today natural gas meets 40% of our energy needs - 340 TWh just for residential use alone (mostly heating homes). Total natural gas energy demand (excluding power generation, export and shrinkage) was 560 TWh. If you need a recap on what kW, GW, and TWh units are please see the notes at the end of the blog.
Natural gas demand in GB 2021 - from NGESO 'Future Energy Scenario 2022'
To put 340 TWh used in heating residential homes into perspective - in 2021 the entire GB electricity generation output that was transported across our electricity networks and consumed by all energy users was 297 TWh - less energy than natural gas supplied just for residential use. Of the 297 TWH of electricity generated and consumed in GB - almost 20% (58 TWh) was generated by burning natural gas. Just think of the all the infrastructure involved in electricity in GB - all the towers, substations, power stations and electricity interconnectors actually carries less energy than the gas networks carry to heat our homes.
Electricity generation capacity (GW) and output (TWh) in 2021 from NGESO 'Future Energy Scenarios 2022'
On the face of it, if we want to stop using the natural gas supplying energy to homes, we would need to more than double our electricity generation (including displacing the substantial amount of gas fired generation) and double the electricity transmission and distribution networks.
If you consider that the transmission network in England and Wales is valued at over £15 billion and has been constructed over a period of 60 years - you will quickly come to the conclusion that like for like electrification of residential heating is not viable. This also ignores commercial and industrial use of natural gas, which is another 220 TWh of energy.
To sum this above up (there are a lot of big numbers!) we use 560 TWh of natural gas energy per year across residential, commercial and industrial users. We only have the capacity to generate and transport around 250 TWh of electricity per year (without natural gas). Back to Jon's question - what do we do if we stop using gas? There are no easy answers here.
Hydrogen To The Rescue
The UK has a pipeline of offshore wind farms estimated at over 100 GW according to RenewableUK. One of the UK's best performing and largest offshore wind farms (Hornsea 1) has produced 12.1 TWh of electricity over its 2.4 year lifespan, with an installed capacity of 1.2 GW - so produces 4.3 TWh per installed GW of capacity. To get a feel of the scale of these numbers, our biggest power stations anywhere in the UK are rated at around 2 GW.
Applying these assumptions to the 100 GW of offshore wind pipeline would give us 430 TWh of renewable electricity per year - enough to replace all our residential natural gas energy needs.
Of course we can't transmit that level of energy across the electricity transmission and distribution networks without massive investment in reinforcement (on the face of it anyway, more on this point later), which brings us back to the picture we started with from the US Office of Energy Efficiency and Renewable Energy.
Graphic from US Office of Efficiency and Renewable Energy.
If we were to stop using natural gas, we can use the now redundant gas networks to transport the hydrogen from the coast (where we already have large gas injection points) to houses with minimal disruption. This feels like a low cost, low disruption solution to a very big problem.
Of course, it is not as simple as that.
A Question of Efficiency
Perhaps the US Office of Energy Efficiency and Renewable Energy lived up to their name and looked at the efficiency of this above process - or in particular the energy lost through the chain from the wind turbine to the house, as the graphic below shows.
100 GW of offshore wind electricity generation end to end efficiency when used for hydrogen to the home. Data from Hydrogen Science Coalition.
We generate 100 GW of clean electricity out at sea, and need to turn this into hydrogen. Ignoring the transmission losses in the cable to land (these are very small), we lose 5% of the energy converting the AC to DC for the electrolysis process. We then lose a further 25% in the electrolysis process.
To store the hydrogen, we need to compress it which results in losses of 10%. Transmitting the hydrogen over the transmission and distribution networks costs a further 20% of energy, before 10% is lost in the hydrogen boiler in the homes, leaving us with only 46 GW of useable energy in the home.
If we use the full future pipeline of offshore wind to create hydrogen which is then distributed to our housing - we lose a staggering 54 GW of energy.
It can tempting to dismiss the losses because the energy is renewable - if no carbon is emitted, then who cares? Well, the installation cost per GW of offshore wind is currently around £3 billion per GW (data source), giving an installation cost of £300 billion. To spread the cost of this infrastructure across the kWhs that flow though all our meters when over half is lost in the conversion process will lead to very high costs - the wasted energy may be 'free' in terms of carbon, but certainly not in terms of costs to end consumers.
Alternatives
The main alternative that shows promise in reducing our reliance on natural gas for heating is heat pumps - essentially an air conditioner in reverse that takes low levels of heat in the atmosphere and concentrates it so it can be used to heat our homes.
Typical ground mounted air source heat pump external unit
Because the energy source is the latent heat in the atmosphere, more heat is produced by the heat pump than is consumed by the motors used to compress the coolant and drive the warm water circulation pumps. The net effect is that for every 1 kWh of electricity that is consumed, 3 kWh of heat is produced (well extracted from the atmosphere as we can't create or destroy energy!)
So what does our same 46 GW of useful domestic heat look like if we supply it over the electricity network using the same offshore wind turbines, without suffering the losses inherent in the hydrogen value chain?
Well, it looks very, very different. To supply the same heating load of 46 GW, we need 17 GW of offshore wind turbines. By any measure 17 GW is a lot less than 100 GW.
Case closed - heat pumps it is
Well not quite. 17 GW still represents a huge amount of capacity that would need to be made available on the transmission and distribution electricity networks.
Drax power station, North Yorkshire, England.
To put 17 GW into perspective, the largest power station we have in the UK is the giant Drax power station that dates from the 1980s - it has an installed capacity of 2.6 GW, and it is a truly massive. massive.
The Solution?
So now we know the size of the problem, and the issues around hydrogen and the scale of the infrastructure we would need if we converted every house to heat pumps tomorrow is massive - what is the actual solution? Well there are solutions, but as eluded to at the start of this blog - it's much more complex than the polarised 'use hydrogen for heating' or 'convert everything to electricity' battle cry. We will explore the solutions in the next blog post in a week. I bet you can't wait......
Last Word on Hydrogen
Hydrogen has to be part of the mix for net zero, but it's use in residential heating in questionable, and in my experience is only really being pushed by vested interests who face an existential threat to their business models when natural gas is eventually switch off (gas transmission and distribution companies, boiler manufacturers etc).
I was invited to a session hosted by the 'All Party Parliamentary group on Hydrogen' last year which is a group of MPs and Lords to have come together to promote hydrogen. The £71k running costs of that group of lawmakers is paid for by Baxi, Bosch, Cadent, EDF, Equinor, Energy and Utilities Alliance, Johnson Matthey, Howden, National Grid, Northern Gas Networks, SGN and Shell - an interesting group of companies in relation to natural gas to say the least. It will be interesting to see if National Grid still help fund the group if they divest the rest of their gas transmission network.
Where there is more promise for low carbon hydrogen is in displacing the hydrogen we already use in industry - of which 90% is formed from natural gas, so very high carbon.
In additional to displacing 'black' hydrogen, we have some very high heat industrial processes that will never be feasible to use electricity for, or are very hard to abte for other reasons (heavy goods transport, shipping etc). These are areas where green hydrogen may play a major role.
But for heating our domestic properties - the sheer losses through the electricity generation/electrolysis/compression/transmission/burning for heat are so high it is very hard to see how it could ever work - but we should welcome the public debate when rooted in fact and science.
Some other issues around hydrogen that are serious but secondary to the efficiency problem:
Our natural gas transmission system ('NTS') is an extensive high pressure pipe network that is constructed mostly of steel pipes. Hydrogen makes steel brittle, so the NTS is likely unable to be used for pure hydrogen transmission
While the local gas distribution networks have had a lot of the old steel pipes converted to plastic, there are still large parts that are steel, as well as lots of valves and other network components. There is no clarity in any of the proposals I have seen from the gas companies on how much cost is involved in replacing these components
Some proposals have been made to make hydrogen from natural gas, and capture the carbon that is released in the process ('carbon capture and storage'). There is no evidence that this will ever work at scale - in fact there is no example anywhere in the world where carbon capture and storage works at the scale we would need, despite billions being spent (it is worth noting that this was once promoted as the answer to coal emissions in the power industry, promoted as 'clean coal'. It didn't save coal....
Thank You
Thank you for reading - next time we will explore the solutions for the problems of getting to net zero. Please do tell me what you think - we need a national debate rather that dogmatic promotion of single solutions, so it would be great to get your thoughts in the comments below.
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Numbers
A quick recap on capacity and energy units. We measure power in watts - to fully heat the element in your kettle which boils the water needs 3,000 continuous watts of power, or 3 kW (1 kilowatt (kW) is 1,000 watts). This is the level of power flowing though the element.
To measure the amount of energy consumed by your kettle, we need to measure this over time. So if your kettle was on boil constantly for 1 hour, with the power flowing though the element measured at 3 kW constantly, your supplier would bill you for 3 'kilowatt hours' (or kWh). If it was on boil for half an hour, it would be 1.5 kWh.
1,000 kW is equal 1 megawatt (1 MW), and 1,000 MW is equal to 1 gigawatt (1 GW), and 1,000 GW is equal to 1 terawatt (TW). Simple.....
The Author
Simon Gallagher is the Managing Director of UK Networks Services and is an expert on electricity networks and strategies around using electrification to get us to Net Zero by 2050.
Having held senior position across the electricity industry over the last 15 years, he advises on electrification strategy, e-mobility and heavy electrical infrastructure.
Simon holds a degree in Electrical engineering from Queen's University, Belfast, an MBA from Warwick Business School, is a Chartered Engineer and is an active Fellow of the Institution of Engineering and Technology (IET).
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