Professor Jim Watson, University College London: Low carbon electricity options

Professor Jim Watson: Okay, so I'm going to talk about two sets of low carbon electricity options. First nuclear power, and second fossil fuels with carbon capture and storage.

So I'm going to move on to slide two now. So nuclear power first. This is slide two. The UK has been using nuclear power generation for civilian electricity use since 1956. The first nuclear power plant was opened then by the Queen, called Calder Hall, and we've been using nuclear power ever since then. Civilian nuclear power is a term used just to distinguish it from nuclear power that was used for military uses. So the nuclear programme in the UK, like many countries, had its roots in the military to create nuclear weapons. And so there is a distinction between nuclear power for civilian uses for electricity, for UK citizens, and the use of nuclear power for military uses. In the most recent year we've got data for, in 2019, nuclear power was generating 17% of UK electricity.

So we currently have eight nuclear plants operating around the UK. Most of those are quite old, and then one of them called Sizewell B, which is pictured on the slide for those of you who can see it, was put into operation in the mid 1990's. So there's eight plants in operation, and then we've got some even older plants which have now closed, and they're now being, going through what's called 'decommissioning.' So all of the work that has to be done to care for and dismantle those plants after they reach the end of their life.

In addition to those eight plants, we have one new plant being constructed at Hinkley C in Somerset. That's a new plant and it will go into operation in a few years time. It's being built by EDF Energy.

So I'm now moving on to slide three. So nuclear could make a much bigger contribution than it does now to our electricity mix. So, as I said, at the moment, it's less than 20%. That could increase quite a lot. So, for example, if we were to build 10 plants like the new one at Hinkley C that is being built right now, which is pictured on this slide, that would generate about 75%, so 3/4 of the electricity we currently generate. So nuclear is a technology which could actually generate large amounts of low carbon electricity. But I think it's important to also understand that if no more new plants are built, because many of the plants we have operating right now are quite old, then that share of nuclear generation is going to decline over time. So if we fast forward to 2030 we will only have the new plant that's being built and Sizewell B, which entered service in the 1990's. Those would be the only two left.

So what are the things that might limit the amount of nuclear power we might build in the UK to help generate a low carbon electricity? One limiting factor is cost. So nuclear power, as you perhaps conceived from the picture here, is a very intensive technology in terms of the resources and the money that it needs to build it. Once you've built a nuclear power plant, they're actually very cheap to operate, so most of the money goes into constructing the plant. And at the moment, for the UK at least, the costs of building a new nuclear plant in the UK is perhaps about twice the amount that we would spend on building a new wind farm or a new large solar plant. And that's twice the amount per unit of electricity that it eventually generates when it's operating.

So one of the big limiting factors is cost. That cost, of course, could come down if we build more of those plants and we have technological change, but the history shows that that's proven to be quite a difficult thing to do. So many countries have had quite a lot of difficulties with trying to make nuclear power cheaper and more cost effective. So that's one of the challenges. Other challenges include public acceptability. Historically speaking, in the UK and other countries, public opinion has been quite divided about whether nuclear power is seen as desirable or not. Part of that is to do with the cost, and part of it is also to do with waste management. So nuclear reactors generate nuclear waste which has to be handled very, very carefully because it's dang-- some of which is dangerous. And also that waste is active, it's radioactive for long periods of time, so it has to be looked after for a long period of time. So even when nuclear reactors have stopped operating like some of the ones we have in the UK, money needs to be spent to manage that waste over a long period of time and find a safe way of managing and disposing of that waste.

So I'm now going to move on to slide four. So what about the future of nuclear power? Clearly, we could continue to build reactors using the technology I have shown you, at Hinkley C, the current large scale technology which is where nuclear power plants cost quite a lot of money, each one, but they do generate large amounts of electricity. There are also other technologies now being developed by companies around the world, which are either use new types of technology or they make the technology much smaller. So small modular reactors, for example, take the technology we have now and then make it much smaller. And the idea is that you could make a lot of these reactors and perhaps make each one cheaper because you're making a lot of them, rather like when you build a lot of wind turbines or solar panels, the cost of each panel or turbine could be lower.

Then there's also advanced modular reactors. They use very different ways of cooling the reactor, different types of fuel, and so on. The time scales for these new technologies are uncertain. Certainly for the small modular reactors, the most ambitious companies think they could build one perhaps in the second half of this decade or 2030. We don't really know how much they're going to cost because nobody's built one yet at full scale. But they could offer us some advantages over the current generation. So the picture there on slide four is just an artist's impression of one of the small modular reactor types that's being considered and developed by a private company, in this case in the United States. So more research and development is required, and probably quite a bit of government funding, either from the UK or other countries, in order to scale up and deploy those new technologies and to see whether they work and see how much they cost. So that's the future of nuclear.

Okay, so that's my slides on nuclear power. So now on to fossil fuels with carbon capture and storage, I'm now on slide five. So carbon capture and storage technologies. You've heard about this in weekend two, so here is a bit more detail on this slide. So carbon capture and storage involves basically capturing the carbon dioxide which is generated when we burn a fossil fuel to make electricity, so a fossil fuel such as coal or gas. When you burn coal or gas in a power station, what normally happens is the carbon dioxide that's produced goes straight up the power station chimney. What you can do instead is to capture up to 90% of those carbon dioxide emissions and put those emissions into a pipeline, and that pipeline then connects to a site where you can store that carbon dioxide in the long term. And that storage can be, for example, a disused oil and gas field in somewhere like the North Sea in the UK, so you can store it for a long time.

The diagram on slide five for those of you can see it, shows just how that works. So you've got the carbon dioxide capture at the power station on the surface, the transport, the yellow pipeline there, and then the storage right at the bottom of the diagram which is where the carbon dioxide would stay for a long period of time.

So fossil fuels generated 43% of our electricity in the UK in 2019. 2% of that was coal, the rest was from natural gas. But it's important to stress that that was done without carbon capture and storage. So the emissions from burning those fossil fuels to generate electricity were going up the power station chimney and causing climate change. Now, carbon capture and storage technology is at quite an early stage. There are a number of full scale plants operating around the world in different countries, not in the UK, but in other countries in North America and Australia and elsewhere in Europe. And two of those are power plants, so they're generating electricity and capturing those carbon dioxide emissions. One in the United States and one in Canada. And those plants opened in the last few years and they're now operating.

So now moving on to slide six. So what's the potential contribution of burning fossil fuels with carbon capture and storage for low carbon electricity? So that contribution could be large, we could build a large number of power stations burning fossil fuels in the UK, all of which could have the facility to capture that carbon dioxide, put it into pipelines, and storing it in reservoirs in places under the ground. We have quite a lot of resources for storage of carbon dioxide in the UK. So, for example, under the North Sea, where we've developed it to extract oil and gas, once we've taken the oil and gas out of an oil or gas field, that creates space where you can then store carbon dioxide instead. And clearly one thing that's very, very important from a climate change perspective is to make sure that carbon dioxide stays where it's put for a long period of time. If it starts to leak out, that is going to negate the impact on climate change because you're starting to contribute again to climate change and global warming. So it's really important that if we're selecting storage sites for carbon dioxide, that they are well understood, the geology is well understood, to minimise the potential for this carbon dioxide to leak out. So that's one of the big challenges of carbon capture and storage.

Another one is cost. So, like nuclear power, the cost of the carbon capture and storage with fossil fuels to generate electricity, is likely to be quite high. As it says here on the slide, it's likely to be the least twice as high a unit of electricity produced as wind and solar power in the UK, at least initially. Now there is potential for that cost to come down as you build more plants using this technology the same way that as you build more plants using, say, wind technology or solar technology, those costs have fallen. So that cost could come down, but initially in the UK, those costs are likely to be quite high. And that's illustrated by the cost of those two plants I mentioned in the United States and Canada, which did have extremely high costs to start with and that's because they're the first plants of their kind in those particular countries.

So that's the end of my presentation. So I basically covered two of the main low carbon generating technologies, nuclear power and fossil fuel with carbon capture and storage. In both cases, the potential for those is quite large. Nuclear power is widely used around the world. Carbon capture and storage is at an early stage. The costs are high in both cases, but there is potential for those costs to come down in the long term. Thank you.