6. Discovery, Design & Deployment: The Science Behind Hydrogen with Tim Mays

Hydrogen has enormous potential as a clean energy carrier, but producing, storing and transporting it efficiently remains one of the key scientific challenges.

In this episode of The Only Way Is Hydrogen?, Karen Brooks speaks with Professor Tim Mays from the University of Bath about the science behind hydrogen storage.

The conversation explores how materials science could unlock new ways of storing hydrogen safely and the importance of collaboration between research and industry.

Because when it comes to hydrogen, our energy security and the planet’s future may well depend on what we build at the molecular scale.

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Transcript

SPEAKER_03 0:16

Hydrogen often gets talked about as a future energy solution, but hydrogen has been utilised for years. The importance is making it clean with endless applications beyond traditional uses. But behind every hydrogen technology, whether it's fuel cells, industry processes or transport systems, there is a huge amount of science making it possible. Hydrogen is a powerful energy carrier, but also difficult to produce, store and transport efficiently. That's where material science becomes critical. Researchers around the world are exploring how advanced materials could help store hydrogen more safely and more compactly and more economically, unlocking new possibilities for its use in transport, industry and energy systems. Today I'm joined by Professor Tim Mays, Emeritus Professor at the University of Bath, whose research has helped shape global understanding of the hydrogen and its uses. We'll explore how this field has evolved, what breakthrough scientists are working towards, and how fundamental research connects to the real-world deployment of hydrogen technology. Thank you for joining me today, Tim.

SPEAKER_00 1:41

It's great to be here, Karen. Thank you.

SPEAKER_03 1:43

Brilliant. So what first parked your interest in materials chemistry and energy research?

SPEAKER_00 1:50

Well, it's going back into the um the last century, the last millennium, when I did my PhD. I won't tell you when, it'll show how old I am. I did my PhD on materials used in nuclear reactors. Uh, and I had great fun. I enjoyed beers being a student, perhaps too much. Um but what it did do, it turned me on to how materials can help um improve energy conversion, energy generation, and in this case in nuclear reactors. So I I I spent three years studying that and enjoyed every minute.

SPEAKER_03 2:24

Brilliant. And so um hydrogen storage has been a focus of your work for for many years. Um how did you first be get involved in hydrogen?

SPEAKER_00 2:33

Like all these things, it's sort of by accident. Um after I finished my PhD, I I did some contract work called postdoc work uh on different materials used in different energy systems. And one of the problems I I was working on, it was a mathematical problem, but it involved understanding how materials behave uh in energy systems. And my old PhD supervisor and later postdoc supervisor came into me one day and said, Um, you know the work you did on your PhD? And I sort of said yeah, and he said, Well, that could be turned to look at some a slightly different system. And I thought, okay, that sounds interesting. And the system was what's called adsorption, and that what happened means is when a gas comes along and sticks on the surface of a solid. Um can you imagine like Velcro?

SPEAKER_03 3:21

Oh, okay, yeah.

SPEAKER_00 3:22

I do understand that, yeah. Well, that's as good an analogy as as any of it. I like that analogy. And the the model I had in my PhD was applicable to this different system, this adsorption system, the velcro system. And the first problem I dealt with was storing methane, natural gas. And this was for um a particular kind of uh energy system using natural gas.

SPEAKER_03 3:48

But when you say natural gas, that's what we use in our homes today. Trevor Burrus, Jr.

SPEAKER_00 3:52

Natural gas uh is exactly what we most of us use in our homes for heating, and actually what's mostly used to generate electricity in power stations. Actually, now that coal has more or less disappeared. And so the the model I had in my PhD was applicable to um natural gas storage. Uh, and then it seemed like a natural progression to go on to hydrogen. If I may tell a little story about how that developed.

SPEAKER_01 4:15

Yeah.

SPEAKER_00 4:17

The EPSRC, the Engineering and Physical Science Research Council, uh opened a competition to um develop a a new consortium for hydrogen, and they invited a load of people along to the Royal Institute of Charlotte Surveyors in London for some reason. And we all went along, they were the great and the good, me included. I was only quite young at the time, and they were trying to establish a group of people to start a consortium to work on hydrogen. And you got these people walking around with clipboards, sort of looking at c looking at people having a chat and stuff like this, and we didn't quite assess what was going on, other than that they were assessing whether or not we were the right stuff, like like astronauts but working in this area. Anyway, a few weeks later uh I was uh in Japan, as it happened, and for a conference, and they rang me up and said, We'd like you to um lead a consortium on hydrogen. And I was quite young, and I think they th they felt that I was sort of gung-ho, and I suppose I was, uh, and but they want me to work with a guy who was professor of chemistry at Oxford, and so the two of us together, it's relatively new early career academic like I was, and this guy at Oxford who was obviously very senior, we worked together for the first large consortium, this is in 2003, and really from that my interest and career in hydrogen really developed. So we worked for I don't know how many years it was, eight or nine years on this consortium, and it was a consortium with lots of people in different areas, so it wasn't just storage, it was production of hydrogen, storing it, moving it around, using it. Uh and I had a lovely time. I enjoyed myself, I enjoyed the power of being the principal investigator, uh, and that really helped my career development. So it was a almost not quite by accident, but it was these things are never linear, they never follow a straight line. And I was just, I guess, lucky.

SPEAKER_03 6:23

Yeah. But so when you first started doing that in 2003, were you looking at green hydrogen or were you uh looking at uh just better production of hydrogen?

SPEAKER_00 6:34

It was everything. It was making more more of it, making it greener, which means using or div uh uh emitting less carbon, carbon dioxide. It was m making use of it um to harness and harvest the energy back out again in a fuel cell or combustion. And actually it was a complete change in direction. From hydrogen is traditionally used in things like oil refining and making ammonia for that goes on to make fertilizer. It wasn't really seen as a very interesting um material or uh substance to to use in energy systems. But because people recognize that climate change was taking over and that resources were in fossil fuel in particular were declining, they're thinking, well, let's open our doors a little bit to new ideas and hydrogen became this potential um medium to um help us move away from from fossil fuels. Incidentally, I prefer the word defossilization rather than decarbonisation because it's getting rid of all gas and and coal. Um so we we were really uh innovators in how to one run a big consortium and two work out how that can really make an impact on technology to help whether it's um green hydrogen, making green hydrogen, low carbon hydrogen, storing it, which was my area, and then using it. So it ran for a a number of years, it was wasn't always smooth running, I must say. Um sometimes the ta challenges we're facing proved to be so tough and difficult. Um but what happened was that started a journey that's now ended up, if I may say, with the projects I was working on until recently uh over twenty three years or so.

SPEAKER_03 8:19

Um and what do you think was the impact from that particular consortium that you were you were working on?

SPEAKER_00 8:24

I think there were two.

SPEAKER_03 8:25

One is how to run a consortium, which is not easy, especially when you have quite early on in in those consortiums in those days?

SPEAKER_00 8:34

They they have been running, but I think that Hygiene is such got a multifaceted thing. It's got lots of things going on with it, and so whether it's production, storage and use, and so it was not only the size of the consortium, it was also the fact that it was people working on lots of different things and they had to be stitched together. So the first thing is how how do these consortia run effectively to deliver in interesting and useful new knowledge and understanding and impact. And secondly, there were some genuine uh innovations on the production side, particularly at um St Andrews, with Professor John Irvine, one of the world leading um physical chemists, uh, and there were lots of interest in enhancing fuel cells, and there were significant developments, even if I say so myself, on storage, particularly in solid-state storage and materials.

SPEAKER_03 9:25

Hydrogen uh is described as difficult to store. You mentioned some work that you'd done there. Why is that? What what what makes it so challenging with hydrogen?

SPEAKER_00 9:35

Okay, well there are two aspects to this. One is that hydrogen has more energy per unit mass, in other words, per kilogram, than any chemical fuel, gasoline, diesel, kerosene, you name it, three times as much. So, in other words, for the same amount of energy you only need a third of the amount of hydrogen than you do of natural gas or coal or any of these or or electricity. Um electricity, no, let's let's move let's not make life more difficult by thinking of electricity. These are chemical fuels used uh like natural gas um and and derivatives of of oil, like kerosene and and gasoline. So on a per mass basis it's brilliant. But it's low density, what that means is the volume that this occupies is enormous. So in order let's give an example, if I wanted to drive a car, say 300 miles, I'd need about five kilograms of hydrogen compared to 15 kilograms of gasoline. However, it would it would occupy a volume as big as the car, bigger than the car, without doing anything to it. So in other words, you have to do a little trailer going along, but you could do, you could do. Um that what I you may laugh, but people did think of not doing anything to the hydrogen, just having it in a big balloon behind you, but that's not really that's not really practical.

SPEAKER_01 10:53

No.

SPEAKER_00 10:54

So the the whole the whole storage problem is how do I get a lot of hydrogen to as small a space as possible? What have you uh done to to to um solve that challenge, which is I wouldn't claim that I've solved them, but I've been involved in people who have. And the first one is is to compress it. Simply put it in a bucket and squash it. And you can do that, and it increases increases the density. Um but it may it takes a lot of work to do that, a lot of energy has you have to put in to squash it. Um and that energy takes away from the energy you want to get back out of it later on. So in other words, it it seems not really efficient in in that sense. It means you just don't recover all the energy you put in. So um you can squash it. But you run out you run out of steam in squashing it when you get to about I'll go technical for a minute, 700 bar.

SPEAKER_01 11:49

Yeah.

SPEAKER_00 11:49

700 atmospheres. So that's 350 times the pressure in your car tire. You run out of steam. It doesn't, it doesn't you can't compress it much more after that. It doesn't, it doesn't work. But it does produce very high density hydrogen, which is good. But you do have to put this lot of energy in. The second one, which is quite even trickier, is liquefying it. And to liquefy it, you need to go to temperatures that minus 253 degrees Celsius.

SPEAKER_03 12:16

That sounds a bit nippy.

SPEAKER_00 12:18

It's pretty chilly. It's pretty chilly. Um, for example, liquid nitrogen is 70 is is minus 200 degrees Celsius, so it's fifty degrees lower than liquid nitrogen or liquid air. So to liquefy it, which does really produce nice high density hydrogen, you need to put a lot of energy into liquefy it. So in the same way as compressing it, you need to put energy in, you need to put and then you need to put a lot of energy into liquefy it. And not only that, but you need to you need to could keep it there. You don't want it to boil off. So you need to put a lot of energy into the materials that contain liquid hydrogen, uh, and you of course you need to make it safe so it doesn't leak. So all this investment means that yes, you get a lot of energy from the hydrogen, but you've put a lot of energy into the containment and getting it there. So liquid hydrogen, high pressure hydrogen. The sexy way, excuse me, is to try and engineer a system that's midway between this high pressure and the low temperature.

unknown 13:16

Right.

SPEAKER_00 13:17

Because that means you don't have to put so much investment into the materials that contain it or to the processes that get you there. And one way of doing this is which really I picked up um from the work they did on natural gas, is that there are materials that contain little pores, holes in them. And typically these pores are uh a a millionth of a millimeter. They're they're literally only a few atoms in diameter. So they've got little holes in them, these porosity. And it turns out that the any gas, whether it's natural gas, whether it's n whether it's oxygen, nitrogen, hydrogen, inside these little pores, it's unbelievable when you think about it. These pores act like a compressor, they squash. And what happens is the hydrogen densifies, becomes de So it's rather like a little nanocompressor. And so in these pores that are a millionth of a millimeter across, you know, you have to you can't it's very difficult to visualize them. Um they act as these compressors. So if you can get the hydrogen in there via this process called adsorption where the gas sticks to the surface. Oh, yeah, it's like the gas is stuck to the surface like velcro, and they're inside these little pores, and these pores squash it down. That's what I've been working on for um and both the theory and the practice of how that will be work at higher temperatures than liquid hydrogen and lower pressures than high pressure gas. Uh and the other uh aspect of it is it's very easy to get it back out. All you need to do is warm it up a bit. It does still have to be cold at the at this at the moment, it still has to be cold.

SPEAKER_03 14:58

But all you need to do is the same temperatures you were talking about.

SPEAKER_00 15:02

No. Um I mentioned liquid nitrogen before. Unfortunately, it still has to be at those kinds of temperatures, about minus two hundred degrees Celsius. But we that that's a lot less energy intensive than minus two hundred and fifty degrees Celsius.

SPEAKER_02 15:16

Yeah, yeah, yeah.

SPEAKER_00 15:17

So we're we're moving in the right direction. And also it can work at pressures maybe um thirty or forty, fifty bar, fifty atmospheres, which is way less than seven hundred atmospheres, which you need for high pressure gas. So we're moving in the right direction on both counts. Higher temperatures, lower pressures. Plus, you need to engineer the materials to have the there's there's a sweet spot with the pore size. It's rid i it and we still don't know why that is. I have an idea, but no one believes me. Um is that there's a sweet spot where you get the maximum density. A little bit bigger, the effect of the pool wall doesn't have an effect. And a little bit smaller, the hydrogen can't get in. So there's like a little sweet spot.

SPEAKER_02 16:00

Because hydrochrom molecules are very small.

SPEAKER_00 16:02

It is very small, but it could mean that the pore width is so small that hydrogen finds it very tricky to get in. Yeah. Especially when the temperature's low.

SPEAKER_02 16:10

Yeah.

SPEAKER_00 16:11

It's not a simple issue of how it fits. It's how it gets in there in terms of the rate at which it gets in there. It could take forever to get in there.

SPEAKER_01 16:20

Right.

SPEAKER_00 16:21

So this sweet spot, and I won't bore you to details, but it's 0.7 nanometers. 0.7 millionth of a meter. And that seems to be a sweet spot. The the process is this, and maybe it's helped to think we make the hydrogen by um elect using renewable electricity to split water, H2O, into hydrogen and oxygen. The hydrogen, um so the electricity is the energy in bit. The hydrogen then we say, what do we do with it? I know, why don't we put it into a uh a spent gas field or an underground salt cabin and we can flip, put the lid on, and when we need the energy back again, we open the lid and off hydrogen comes, and then we can harvest the energy by burning it or putting it through a thing called a fuel cell. And in the current world where there's geopolitical uncertainty every day of the week, it seems to me, this idea may be very, very attractive because what it'll do, it will remove the the the um necessity of buying electric buying electricity or buying fuel from Europe or further f further afield. So this energy security aspect from hydrogen is very interesting. And it's energy storage. Use the renewable electricity. And some people will say, Well, why don't we just use the electricity that's generated from a wind.

SPEAKER_02 17:40

Yeah, absolutely.

SPEAKER_00 17:41

Well, the thing is, uh renewable electricity is intermittent. Solar, for example, day and night, day and night. Wind is unpredictable up to a point. And what happens is that demand demand for electricity doesn't always match when you're making it.

SPEAKER_03 17:56

Right, yeah, yeah.

SPEAKER_00 17:57

And what you want to do is when there's more electricity than you need, why not use that excess as it's called to split water? That generates the hydrogen and oxygen. You then put the hydrogen away in a salt cabin, or it could be into some of the systems I've been mentioning, high pressure gas, liquid, or solid state, and then recover the hydrogen later on when you need it, it could be seasonal, winter to to summer. The other way is it'll be summer to winter because you have a lot of sunlight from solar PV, photovoltaic. And so hydrogen has a re and that was the real original reason why people are interested in hydrogen, is a way of storing excess renewable electricity.

SPEAKER_03 18:43

So obviously we've talked a lot, um, Tim, about uh storage of hydrogen. What are some of the other challenges that research is looking at to uh ensure that hydrogen can be used in, you know, we talked about smoothing out the the the patterns of uh the usage of electricity in the grid, many other applications which I'm sure we'll touch on. But um what are the other things that you need to solve for us to really be using hydrogen in our energy system?

SPEAKER_00 19:12

That's a good question. I think that think of what's called the value chain. You start with making it, you then move on to storing it and moving it around, and then you use it. And that's called the value chain. And each of them have have difficult technical challenges. We've mentioned storage. Now making it is not just a case of putting electricity into water and off comes hydrogen. I mean that's what happens, but you need to do it effectively. And that's not always straightforward. So the materials that are used in what are called electrolysers, using electricity to split water, they they need to be more efficient, they need to be lower cost, uh and they need to be made so you don't have to rely on um very rare elements and metals to to run them. So there's a lot of interest in in developing low-cost, uh efficient electrolysers to make what's called green hydrogen. Green because it's made from renewable renewable electricity.

SPEAKER_02 20:09

Yeah.

SPEAKER_00 20:10

So it's all very low carbon. So production, um, you can also make hydrogen from heat. And people are thinking of the high temperatures in future nuclear reactors. The UK is now committed to having a next generation of nuclear electricity that can be used to um the high temperatures inside the reactors can be used to generate uh hydrogen by split essentially breaking down water, hydrogen, and oxygen. And in fact, the uh the the hub that I was involved in before I retired uh had a meeting recently with the nuclear industry in order to try and explore what needs to be done for future nuclear reactors.

SPEAKER_03 20:50

Would that be that hydrogen then would be used as the energy source for um the nuclear reactor?

SPEAKER_00 20:57

Not really.

SPEAKER_03 20:57

It doesn't or it's a byproduct.

SPEAKER_00 21:00

It doesn't imply that the hydrogen will be used in a nuclear application. All you're doing is generating a fuel that can be used in all sorts of ways. Okay, so it would it it would um then be able to go on and be used as you could do you could use it to store electricity in the same ways that we mentioned before, but we can go on in a minute to talk about other things that you can do with with hydrogen. So the production side is very important. The end use is also what what are you gonna do with it?

SPEAKER_03 21:28

Yeah, yeah, absolutely. And we've been exploring some of that in these podcast episodes.

SPEAKER_00 21:32

Absolutely, and and store and and there's one of the biggest problems with hydrogen is is to people want to make it and people want to use it, but they're not always matched up. And you to make an economy work, you need to ma match up people want to make hydrogen, they want to know they can sell it to a user. And a user wants to know that they can develop their use systems with lots of available hydrogen, and that's not always matched up. Will drive it. You're quite right. Anyway, so the end use. Now the end use I've mentioned to you before, you can harvest the energy back from hydrogen using either combustion, you can burn it, in the same way as you burn natural gas. And that could be used for heating in buildings and people's homes. You can use it to generate electricity in a big gas turbine, in the same way as natural gas is used now. You can also use hydrogen, for example, in the ceramics industry for glass and and glasses and ceramics. And you may know that these involve very high temperature burners. Now traditionally they use natural gas or meth or propane, another form of hydrocarbon. You can use hydrogen. Especially as the product doesn't think about combustion or any way of harvesting hydrogen, there's no carbon there. There's no carbon. So the beauty of this is that you can burn it, but you don't produce carbon dioxide. So hydrogen has this sort of multifaceted side to it. It can be used in and you mentioned iron, ceramic manufacture, heating, chemicals, particularly ammonia, but other ones. And so in other words, we're sort of s we're cutting the cord with um fossil fuels. We don't know we don't need natural gas, we don't need coal, we don't need oil. Hydrogen can do the job. But you've got to make it. And I mentioned to you before, without making it effectively or efficiently, then you're in in a difficult position. You've got to move it around. Mm-hmm. And finally you can then direct it towards whatever you want to use it for. Whether it's um rainy day storage or seasonal storage, as I mentioned, but it could be into these other industries. And that's the beauty of hydrogen, its flexibility and its adaptability. And you mentioned transport. That is a big potential use. We've all driven around recently in cars with diesel gasoline. You can do that with hydrogen. So hydrogen is perfectly uh uh um engineered to uh in a car for you to drive around in and um it doesn't produce any carbon dioxide, it only produces water at the tailpipe. You'd need the storage is probably the most difficult bit because you don't want a car that's dominated by the store.

SPEAKER_02 24:28

No.

SPEAKER_00 24:29

And in fact, car manufacturers will not do that.

SPEAKER_03 24:32

No, my new car is a hybrid um electric and um uh petrol. Um, but that has a very small petrol tank because of the fact that hopefully I'm generating quite a lot of uh charge as I drive, um, which can so it can use the battery um for some other time.

SPEAKER_00 24:53

Well, I have no problem with electric vehicles. I think they're a very attractive option, provided that you get the electricity from renewables. I'm not so much a fan if you get all the electricity from burning car natural gas, because that produces CO2. So even though you don't produce forgive me, but even though you don't produce CO2 at the point of in your car, it may be produced upstream when you're actually generating the electricity. It does help with um air quality, I don't doubt no doubt at all. Going from a to a hybrid or a fully electric vehicle compared to diesel will improve air quality and it reduces noise. But we can't forget that most of the time you're getting electricity from burning natural gas. So it's not entirely neutral. Um you're right. A motor vehicle will need very specific kind of engineering solutions so you don't dominate the the um the vehicle by the store. But here's an interesting trick. One of my PhD students, a lovely lad called Will Will Forshaw, is working on a concept called swapping. And what that means, instead of going to a car and having a little sort of like a gun and feeding in the hydrogen, you just swap the tank. So, in other words, the tank is in the car, when it's empty, you take it out and someone else puts it in in a refueling station. And so you don't have to you don't have to worry about ultra-high pressures, you don't have to worry about uh all sorts of the fancy tricks of the trade for m working with hydrogen, someone else does that. And swapping could be a potential way. So in other words, you run low on the fuel, so you don't have to have a massive tank, you just have to have lots of refueling stations. So you're you're transferring the the role of um of storage to somebody almost like to somebody else. So someone else makes it, someone else puts it in a the um these tanks. And it's the same way you may have heard of swappable batteries.

SPEAKER_03 26:52

Aaron Ross Powell Mm-hmm. Yes, I've seen this. I think in um Japan or China they have the cars um uh uh driving up and they just swap them over.

SPEAKER_00 27:02

Trevor Burrus You can do it on you can do it with cars, you can also do it with motorbikes and things like that. So in other words, um it's someone else's responsibility to deal with the battery when it's flat or with a hydrogen tank when it's empty. Now this is quite a cutting edge, if I may put it that way. No manufacturer has yet committed to this technology. But because I think because of the recent horrible events in the Middle East, people are now thinking that we really need to look inward, you know, homegrown energy. And hydrogen can deliver that because we do have a lot of natural um renewable energy resource in the UK. And in fact, we're very lucky. Lots of wind, um not so much sun, but enough. Lots of wave energy and tidal energy. So I think that hydrogen will play a big role in this sort of transition, not only to move away from carbon emitting fuels, but also to be working with homegrown so we don't rely on on imports.

SPEAKER_03 28:04

So, Tim, you've been working with hydrogen for a long time now. Well, uh you're you were a child when you started. I was um but so how would you describe hydrogen in one word? And I know you're gonna give me more than one word.

SPEAKER_00 28:21

I know No, I can give you a long word. Multifaceted.

SPEAKER_03 28:26

Okay.

SPEAKER_00 28:27

Because of its uh use and it's uh and the way it can be used or particularly the way it can be used, I think multif it can turn its expertise, if I can put it into uh hu human terms, heating, power, chemicals, um heavy industry. And there's a lot of it about. You know, hydrogen's not a rare commodity. Uh water's f I wouldn't say free, but water's the ultimate source for hydrogen. I don't I'm not a expert on um bio-inspired hydrogen, but you can get hydrogen from biological sources, but mainly we're thinking of using electricity to generate hydrogen from splitting water or heat. So I think that the the the idea that it's it's multifaceted, it's got lots of things going on, and then that maybe have held its back a little it held it's been held back a little bit because people want a simple answer, and there isn't one. There isn't a simple hydrogen will do this. Well it could do this, it can do that, it can do that, and do the other. And I think that that can mean that it's not clear in people's minds if they haven't been working in it for a long time, like I have. So it it didn't it wasn't it wasn't straightforward for me to understand the complexity of the system. I'm now a big fan, but I do understand that there are other options that are easy h easy fixes, and a good example in the UK is um reinvesting in the North Sea. But I think ultimately the price we will pay if we don't invest in hydrogen and nuclear. I'm a big fan of nuclear, um, will be the consequences of being vulnerable to energy supply, and secondly, um in a longer term, having to deal with the dreadful potential complex consequences of of climate change. I'll give an example if I may. You may have heard of a thing called a heat pump, which is um a way of using electricity to heat your house. And there there was a there was a an article on on one of the evening news broadcasts on on Radio 4 where the the measure of how a heat pump works is called its coefficient of performance. I'm afraid I can't avoid these statical terms. And it's a number bigger than one. And it just measures how f how effective the mach the the heat pump is. So the number could be two or three or something like that. And I remember one of the the broadcasters saying, which is magic. You're creating energy out of thin air. No, no, you're not. That number is not efficiency, it's just the number that allows you to compare different heat pumps. My heat pump's better than your heat pump. It is a macho thing. And that drives me nuts because people then say, well, why why do we even bother thinking of hydrogen for heating? Well, it you you're not gonna have a heat pump in a flat. And we we're we're where we are in Bath at the moment, there are there are quite a big lot of flats and single um single occupancy build uh uh uh uh accommodation where you simply can't put a heat pump. And I've seen pictures of heat pumps, they're that big. Okay, if you've got a really big garden, if you're in a detached house or on a uh in a semi uh or you've got some bit a bit of land around you, no problem. I don't have a problem with heat pumps. But it's it's what fits where you live. Now that down here, was it Snow Hill, you wouldn't be able to put heat pumps in those buildings and those flats because where would they go? So heat pumps might not all be this um s solution to everything for heating. And there are some people that will promote heat pumps because of this number, this coefficient of performance, saying, well, it's like magic. And I remember the word on the radio, they're magic.

SPEAKER_03 32:22

I think as we've heard today, if uh people understand how hydrogen is generated or can be generated from renewables, then that is magic and it is out of thin air because a lot of it could be from wind energy or from solar. So um I think that's a lovely point for us to finish on. You know, um hydrogen is as magical as a heat source pump um and uh and and electricity. It's we need this mix, and it depends on where you are, your location, your uh topography, and everything that we've been talking about. So thank you for debunking some of the myths today around hydrogen and helping people to understand it a little more.

SPEAKER_00 33:05

It's been a pleasure, Carol. Thank you.