Jenny Hill, Committee on Climate Change: Where our energy comes from

Sarah: So we're now going to hear from our second speaker. So we're now gonna hear from our second speaker, who is Jenny Hill from the Committee on Climate Change.

Jenny Hill: Hello everyone. So thank you very much for having me here. It's a real pleasure to be here. I work alongside Chris, who you met last weekend. Do you remember him? I'm guessing? Fantastic. Okay, so Jim has covered energy and electricity, and I now have 10 minutes to take you through some tricky topics which are alternative sources of energy. So bear with me, but we're going to get through this together. Right so, I just want to recap very briefly. Now, we've heard this a couple of times this morning, so I'll do it very quickly. Net-zero means, first of all, cutting back on emissions to the atmosphere and then balancing out the rest. And there are two ways that you can try and do this balancing.

So firstly, you can grow trees which absorb carbon from the atmosphere as they grow. Because essentially they only take up a limited amount, everyone, or at least a lot of the expert community are really behind us going down the route of lots and lots of tree planting. But because we're interested in ways which we could potentially go further, that's where there is some discussion of additional technological options. So you have heard about a couple of these so far. Chris last weekend mentioned something called direct air capture and that is essentially where you would try and use electricity to suck carbon out of the atmosphere and then store it long term.

Yep, sure, thank you. Okay.

The other thing that we've just heard about from Jim is called carbon capture and storage and that's also referred to as CCS sometimes. And that is where we start with the fuel and we try and remove the carbon from the fuel either before or after you use it, and then again store it long term. So I want you to just bear those things in mind because they're going to come up a couple of times in my presentation. Right. I am going to whizz through three things. I'm going to talk to you about hydrogen. I'm then going to talk to you about bioenergy, which is where we use plants to produce energy. And then finally I'm going to cover something called synthetic fuels, and I'm going to focus mainly on the first two because for reasons that I'll come to, they're really the big topics that we're going to focus on.

So some of you may have noticed if you're looking at the title of the slide, there is a question mark here. And that is a very important question mark because these sources are not necessarily low carbon. It absolutely depends on how you do it. So this should look familiar. I'm going to just very quickly, I just wanted to essentially use it to talk to why we're interested in alternative fuels. And basically there are two reasons. So the first reason is whilst we think electricity is, Jim was saying, is probably a really, really important part of the answer, it only goes so far. So we think it's a great solution for cars and vans. I think you can use it in some bits of industry. And we think you could use it also potentially to heat lots of our buildings. But that leaves us with certain bits of our energy system, where we don't think electricity is is the easiest thing to use.

And that's where if you have something like hydrogen, wow that was dramatic. Hydrogen. If you have something like low carbon hydrogen. By low carbon, I mean, you can produce it in ways which don't lead to lots of emissions going into the atmosphere. So if you have enough of that, then we think that, the Committee on Climate Change, that potentially you could then use it for things like bits of industry, but also heavy transport, so things like trucks and ships, and potentially also buildings. So then - So that's the first reason we look at alternative fuels.

Second reason is coming back to what I was talking about the beginning. So if you have the ability to capture carbon from fuels and store it underground, then there are experts who think that what you could do is basically combine that with bioenergy and the logic there is that what you're trying to do is remove emissions from the atmosphere. And so the idea is that as trees grow - as trees grow, they absorb carbon dioxide. You then take that fuel and use it and when you use it, you capture the carbon and store it long term. So you basically, in theory, got this flow going from the atmosphere into a store, if you can get it to work. Now, that's a big topic. So we're going to come back to that in weekend four.

Right. So, first up hydrogen. You heard in the first weekend that there are basically two ways that we can produce this without leading to lots of emissions. The first is using electricity and water and that is sometimes called green hydrogen and it's pretty expensive in the UK at the moment, which is why a lot of interest or there is a lot of interest in this second route which is using fuels using this carbon capture and storage, that sometimes called blue hydrogen and a lot of the discussion is around how we could potentially use something like natural gas to do that, and it's a bit less expensive at the moment, we think than the first route. So we are mainly going to hear about hydrogen in our topics where we look at what we can do in the home, which I have the pleasure of joining some of you for. And we'll also talk about it for how we travel.

Okay, second up, bioenergy. Now, this is a huge topic, and I am not going to be able to do it justice. But this is a whistle-stop tour. So there are quite a lot of uses. You can use it for electricity, for heating, for cooking, for transport. It also comes in lots of different states, so it could be solid, those of the wood pellets or just the wood that Jim mentioned. It could also be liquid and you may well have heard of biofuels used for transport, even seen them on petrol forecourts. And then last of all, we've got a range of gases that can be from plants. So one of the main ones there is actually, I don't know, some of you may well have your food waste, which is currently being collected separately by your local council. And if that's happening, then there's a good chance that is being taken off and being used to produce what's called biomethane. And that occurs naturally when wet wastes breakdown under certain circumstances. And at the moment in the UK, we are actually upgrading some of that and piping it back into the gas network, so it may actually be powering some of your homes already. So we got biomethane, and I've mentioned here briefly hydrogen if you strip out the carbon as we discussed.

Okay. So the key thing that I really want you to remember here is that the supply of this stuff around the world is limited by certain factors. So most of it needs land to produce and it needs to be done in a sustainable way if you're going to see the benefits in emissions terms. And so there's a lot of research which goes into trying to estimate how much of this stuff we really have and essentially it is limited. Even if we try and expand it and that means that we really need to use it as efficiently as possible. So two quick examples. When I and colleagues looked at this a couple of years ago, we looked at all of the evidence and essentially the numbers that we came out with were that if you were to take our best estimate of what sustainable supply could be and so you were to use that for air travel, then it's actually likely that that air travel could use up all of your supply globally. And that is dwarfed by the amount that you might need if you were to take all the plastics that we currently use and trying to switch them over to plant plastics. So that's the key thing.

Okay, so it's controversial for two reasons. Firstly, there is a huge range in terms of the potential benefits. If you're doing it right, so you're using waste, you're replanting, et cetera, then it can be really, really good in carbon terms, but at the very, very worst end of the range, in worst-case scenario, it can actually be worse than fossil fuels. And that we don't think is very common, at the Committee, but it is a risk. There are also a lot of issues to with the fact that it comes from land, so you may well have heard in the news that they have been historical cases of it, driving up food prices where land has been used to produce energy crops instead of food. So you have to be doing it right. You have to have the right systems in place. And some people would argue that you're more likely to be able to do that if you're looking at UK sources rather than international sources.

Now, finally, very quickly I'm going to mention synthetic fuels. These aren't currently being discussed at the same level as hydrogen and bioenergy, but we wanted to touch on them briefly. They are mainly being considered by parts of the energy system where you really don't have other options. So the example really I've got here, is air travel, and particularly long haul air travel, where the aviation industry don't think that, according to their best estimates, they'll be able to use things like electric planes. And as we heard biofuels are limited. So then that pushes you to look at other things, and one of the things you could do is try manufacture fuels that you could burn in a plane and you might do this by taking hydrogen, combining it with a source of captured carbon and then you'd get the synthetic fuels. And essentially some people clearly think they could play a role. Other people are concerned about the potential cost. And we think that the bit where you use the carbon, if you do this rather than storing it, it could be five times more expensive. So there's a real question as to whether the aviation industry are going to take this forward and that is something we'll come to briefly in the transport session. Okay. Thank you.

Sarah: So again, I'm just gonna give you some time to write down the question each that you would most like to ask Jenny.