Using hydrogen as a fuel has been gaining a lot of traction in the last few months. I have been brooding on it for some time and wanted to share my thoughts and reflections on the new ‘wonder fuel’.
Follow the money
There has been a concerted effort to promote Hydrogen by various people on LinkedIn and I thought it was suspicious how suddenly it was the shiny new toy in town. It is unlikely that this level of traction would have occurred unless a good number of people were in some form or other in receipt of money, whether by employment or as consultants.
As they say in the movies, “follow the money”. Who stands to gain or benefit from all of this hydrogen production and consumption? Luckily, it does not take the brains of a rocket scientist to correctly narrow the focus in on the oil and gas industry. They have the resources and lobbying might, that other industries can only gawp at, and they would be the sole beneficiaries as they have the knowledge and infrastructure to capitalise on this “wonder fuel”.
What is the problem with hydrogen?
The basic premise is that when you burn hydrogen, the only “waste” or “by-product” is water vapour, it is essentially a fuel without the shame of contributing to climate change.
Before we go any further it may be useful to decode our colour-coded hydrogen so to speak.
- Green Hydrogen: Essentially, if you pass a current through water (electrolysis), oxygen will form at the anode and hydrogen will form at the cathode. If the electricity comes from say wind turbines or solar PV, you can safely argue that the hydrogen produced is “zero carbon”.
- Grey Hydrogen: This is where natural gas (or coal) is split into hydrogen and CO2 either by Steam Methane Reforming (SMR) or Auto Thermal Reforming (ATR). Both these methods emit large amounts of CO2 and also are incredibly energy intensive. Currently, 98% of the world’s hydrogen is produced this way. It could be argued that history is about to repeat itself, because in some ways we are going back to producing Town Gas utilising these processes to produce gas for the home.
- Blue Hydrogen: Is the production of hydrogen derived from natural gas as above BUT, all that nasty carbon dioxide is captured and buried in the ground somewhere forever. Well that’s all right then…..
(There are also Yellow and Pink versions of hydrogen but let’s leave them aside for now…)
So, what is the problem? Well, the problem can be broken down into several distinct areas:
Elon Musk of Tesla famously described using hydrogen fuel cells in cars, and I quote, as “mind-bogglingly stupid”. His reasoning was from the point of view of an engineer and not a paid consultant. The average petrol car may get about 40miles to the gallon, the average Electric Car (EV) based on 33.7kWh equalling 1 US gallon is 120miles to the gallon. The Toyota Mira hydrogen fuel cell car gets a mere 27 miles to the gallon equivalent. Hopefully, the maths speaks for itself. Converting hydrogen to electricity in a car is complicated and very inefficient.
The same inefficiencies apply to using hydrogen in the home. Ignoring all the other issues outside the home, if we deliver 1kWh of hydrogen to a gas boiler, it may produce 0.9kWh of useful heat. An air source heat pump with 1kWh of electricity may produce 3kWh of useful heat, making it at least 3x more efficient. Now this may not seem important until we understand that eventually all hydrogen delivered to the home will be produced using electrolysis, which uses lots of electricity. So still ignoring the efficiency outside the home, if 1kWh of electricity produced 1kWh of hydrogen (it doesn’t by a long way which we will come onto), it would be 3x more efficient to deliver the electricity directly to the home and bypass the hydrogen boiler altogether.
The idea that in the future there will be mountains of cheap energy lying around, meaning that energy efficiency of any system is unimportant is absurd. Energy efficiency of every system will be of paramount importance to future generations to help them live in a zero-carbon world.
Currently 98% of global hydrogen production comes from coal and gas feedstock, commonly known as “grey” or “blue” hydrogen. This in itself is an energy-intensive process of reacting coal with oxygen and steam under high pressure at 1100oC, producing a mixture of carbon monoxide and hydrogen. Further processing of the carbon monoxide via a “water gas shift reaction” produces a bit more hydrogen and yes, you guessed it, lots of carbon dioxide! This is where Carbon Capture and Storage (CCS) is supposed to come in. The oil and gas industry inform us, with a straight face, that they are going to inject this into bedrock to enable them to extract more oil and gas and that is a good thing. Perhaps not. Studies have shown that there is no guarantee that any of this injected CO2 will behave itself and stay there for time immemorial.
Jacob Engineering wrote an extensive report which can be trawled from the internet that shows that an electrolysis technique for producing hydrogen might be 68% efficient in the future. So going back to the home example above, ignoring all other efficiency losses, using this process would be 5 times less efficient than using a heat pump. This is just plain nuts. There is a process that might come to scale by 2050 which is 300% efficient if you can utilise waste heat from another process. However, if we wait until 2050, we will be way past the tipping point for our Climate and our children will have to adapt to the legacy that we give them.
Finally, we are not allowed to mention the 20 litres of tap water per kg of hydrogen that would be required for ‘green hydrogen’ production. That roughly equates to a pint per kWh, so each house would consume another 6 tonnes of water per annum on top of the 130 tonnes that they get through splashing about in the bath. Fag packet figures come out at 38,400,000,000,000 litres for the whole Gas Grid each year.
The National Grid is confident that the gas grid could cope with hydrogen gas. However, there is a thing called embrittlement and hydrogen is well known (due to its tiny size) to get just about anywhere in anything and in metals hydrogen diffusion can make them brittle and they then fail. Luckily, in the UK we only have 7,500km of large diameter high pressure steel gas mains to worry about. Phew………. It remains to be seen whether due to its size more leaks will occur and that we get more incidents. The other minor issue is that its calorific value is only about one third that of “natural” gas, so presumably, we will need 3x as much gas volume in our network and homes? The intention is to increase the pressure of the system, which would presumably increase the likelihood of leaks.
Please, whatever you do, don’t mention cost! The poor souls in the oil and gas industry are likely to come out in a rash if you dare ask about the cost. Luckily in terms of capital cost of creating production facilities and all the carbon intensive rest of it, through tax relief – and no doubt handouts – it won’t cost the industry too much. However, the taxpayers will be on the hook one way or another. Jacobs estimates that the cost of converting the Gas Grid is currently £22Bn. To put that into context, we could build 5GW of offshore wind or 14GW of onshore wind for the same money. The cost to buy hydrogen as a consumer is very likely to be an expensive proposition. Best estimates are that production of proper green hydrogen could come down to 48kWh/ kilogram which at 4.5p/kWh for wholesale electricity comes in at 6.5p/kWh for hydrogen. To this figure one must add capex and maintenance and transporting and profit and tax etc before the hydrogen comes out of the pipe in the home.
For the CCS and grey/blue hydrogen scenario, you also have to add in the costs of capturing and storing the CO2 and this adds some serious extra costs which will have to be borne by the consumer.
It seems likely that hydrogen will cost twice as much to the householder as “natural” gas per kWh, so if your fuel bill doubles at least there is an incentive to improve the thermal performance of the home…
It is widely accepted that the oil and gas industry used the same playbook as the tobacco industry to prolong their profitable existence by sowing seeds of doubt as to the science underpinning our understanding of climate change. Arrhenius calculated at the end of the Victorian era that if CO2 levels doubled then the climate would warm by 5oC. When he did those calculations, the CO2 levels were about 270ppm, today we are North of 415ppm.
It seems clear that hydrogen especially when coupled with carbon capture and storage is part of this pattern of behaviour, stalling the inevitable decline by promising carbon-free ‘jam tomorrow’.
Currently, the oil and gas industry predict that there will be only a slight reduction in gas consumption in the UK by 2050. They are planning to introduce 20% hydrogen into the Gas Grid over the coming decade and then as “technologies emerge”, making hydrogen cheaper and greener to switch chunks of the network over to hydrogen such that by 2050 the whole Gas Grid will be supplying 100% hydrogen.
I remain to be convinced that green hydrogen production will ever be green or cheap for all of the reasons stated above.
Energy efficiency: The first fuel
Those of us extolling energy efficiency in the home, which is the cheapest, cleanest way of reducing carbon emissions at a macro-economic level, fear that the consultants that have the ear of ministers are telling them, “Don’t bother with insulation, let us pipe hydrogen to everyone’s home instead”.
A criticism of Boris often cited by those he has worked with is that he likes the big picture, not the fine detail and the fossil fuel lobby are parading a simple message of hydrogen instead of “natural” gas as the answer to all our problems. It is clear from the above points; this is far from the case and that our children will have to deal with the mess which we will inevitably leave behind if we allow this to happen unchallenged.
A role for hydrogen?
Hydrogen has an important part to play in our future energy mix, especially for industries such as chemicals, cement and steel. It may well have a role in international shipping and aviation in future decades too.
However, to squander hydrogen on producing heat for the home and transporting us over land is, in the words of Elon Musk, “mind-bogglingly stupid”.
LETI guide to hydrogen: www.leti.london/hydrogen
Alex Honey is a Passivhaus Designer with Enhabit’s Norwich team.