Fusion energy and why it is important to chase the impossible | Melanie Windridge | TEDxWarwick

but difficult is what takes a little time the impossible that's what takes a little longer this is a quote I love it's by free top Nansen scientist polar explorer humanitarian I learned a lot about him when I was traveling in the Arctic learning about the Northern Lights I love this quote because it just travels all over the word impossible I think very few things are actually impossible they just might not be possible now and in my work I truly believe that I work in fusion energy I work for a company called tokamak energy now if any of you have heard of fusion you may have heard the old joke that fusion is 30 years away and it always will be for those of you who haven't heard about fusion energy it's the dream of energy production here's the thing fusion produces no greenhouse gases no longer radioactive waste but it would generate huge amounts of energy from almost inexhaustible fuel it's the reaction that powers the Sun and the stars and since scientists realized what was causing the Sun to shine they've been dreaming about harnessing this reaction to make clean energy for mankind I first heard about fusion after I just finished studying physics a university I was on a gap year traveling working and wondering what to do with my life back then just out of university I was concerned about climate change and what we would do for energy when fossil fuels run out this was reinforced when I went diving and I saw coral bleaching on the reefs I hiked in the mountains and learns about base hill retreat I was seeing science in the landscape I was still interested in physics are still reading scientific magazines and one day I read about fusion clean green safe and abundant I thought if we could do this it would be incredible it would solve our energy problems you see I don't want fossil fuels to run out I'd like to be able to stop using them I don't want us to have to drill for oil in the Arctic or other fragile locations but the world needs energy worldwide energy demand is only increasing and whilst renewables will go some way that's filling the gap they will struggle to supply densely populated areas with high demands and little space fusion offers us an alternative we can do things differently that's why I decided to do a PhD in fusion energy Fusion is clean and safe it produces no greenhouse gases and no long-lived radioactive waste the fuels for fusion are types of heavy hydrogen deuterium and tritium they come together to make helium and a neutron and lots of energy in fact fusion produces huge amounts of energy for the weight of fuel just one kilogram of fusion fuel produces as much energy as 10 million kilograms of fossil fuels this means that an effusion power station in one day would be able to use about one kilogram of fuel that's like a big bag of sugar whereas a coal-fired power station everyday uses hundreds of truckloads of coal so that's quite a difference the fuel Fusion has spread all around the world and studies have shown the fusion will be competitive with other sources the thing is Fusion has taken decades of research so far and some think the fusion will always be an impossible dream I don't believe that's true and I want to tell you why first of all let me tell you Fusion is really hard to do we're trying to replicate the Sun on earth that's like trying to put the Sun in a box this is intense hostile conditions it's not dangerous because if the conditions aren't perfect then everything stops but these hostile conditions and the amounts of energy produced means that designing and building of fusion power station is really tricky so it's going to take time but we're making progress I work with machines called tokamaks like this one here now you're probably wondering where the word tokamak comes from it's quite an unusual word well it's actually a Russian acronym because of the Russians that came up with the design it stands for oil night camera Mikey's marketers yet which it's a bit of a mouthful but it actually describes exactly what a tokamak is it means to oil don't chamber magnetic coils so it's a toroidal or ring doughnut shape chamber with magnetic coils around the outside the make a trap for the hot fusion fuel called plasma tokamaks have been very successful over the years and this one here is the best performing in the world so far it's called jet and it's located at Cullum in Oxfordshire which is where I did my PhD scientists have done the fusion on this machine they've made real fusion reactions one thing they haven't done yet is get more energy out of those reactions than they put in this is quite important if we want to make a power station over time tokamaks have been getting bigger and bigger this was a logical approach and I want to show you why so I've got a little equation for you this here simply says that the fusion power that we get out depends broadly on three main things efficiency of the machine beta we call it this magnetic field strength beam and the volume of the plasma or its size increasing any of these things will increase the fusion power that we get out but you can see from the numbers there the powers but magnetic field strength has the biggest effect fired by efficiency followed by volume now in a conventional talk efficiency is pretty much fixed so it's difficult to increase that the magnetic field strength that's the most expensive part of the machine and it's also limited by technology so it's difficult to increase that the simplest thing to increase is the volume of the plasma so tokamaks have been getting bigger and bigger so going back to jet jet started operating in 1981 when I was a baby it's a great machine and it's enabled some incredible research over its lifetime the problem is that the fusion community is still waiting for the next machine eita itza is two or three times as big as jet and it's an incredible piece of engineering but it's been politically and bureaucratically challenging and it's been very delayed it's currently under construction in the South of France but it won't start operating until the end of the next decade by which point I'll be well into my 40s and itzá won't even be a pilot plant they'll probably need another perhaps bigger machine after that so you can see why they say that fusion is always 30 years away but this is when it gets interesting you see over my lifetime technologies have changed quite a lot the mobile phone emerged in my teens the smart phone in my mid to late 20s when I was a child I used to listen to my music on a portable cassette walkman like this but either was being designed when was listening to my walkman surely there have been advances in technology that could be incorporated into newer tokamaks well there have been and in 2013 I started working with the company tokamak energy who are doing just that we're aiming to show that fusion energy could be commercially viable by 2030 tokamak energy are working with two technologies to develop compact fusion that is smaller machines that we can build cheaper and faster these two technologies spherical tokamaks and high-temperature superconductors now a spherical tokamak is just a squashed up tokamak so it's rather than having a ring doughnut shape it's more like a cored Apple in shape and superconductors well they're those cool materials that can levitate a superconductor has no electrical resistance which means that it doesn't heat up when a current flows through it like when you make an electromagnet conventional tokamak magnets made from copper will heats up in a minute or so and then the machine has to stop and that the magnets cool down before it can operate again but with a superconductor the magnet wouldn't get hot because the current can flow continuously without heating up so future fusion power stations will need to use superconductors for continuous operation and in fact ether will have superconductor magnets now assuming that does only superconduct at very low temperatures near absolute zero conventional superconductors worth about minus 2 69 degrees C high-temperature superconductors can work at minus 200 degrees C now it's still really cold but that's a big energy-saving high-temperature superconductors also perform better they can achieve higher magnetic fields and they can take up less space why is this important well the combination of these technologies mean that we could design smaller fusion reactors let's have a look at that equation from before if you remember fusion power scales with efficiency field strength and volume well sparkle tokamaks have higher efficiency high-temperature superconductors can achieve higher magnetic fields so if we can increase efficiency and feel strength then we don't need to increase volume so much we can make smaller tokamaks now we're not talking tiny here you're not going to be seeing a fusion reactor in your car anytime soon in fact a future fusion power station will probably have modules as big as the jet tokamak but they'll be much easier to build than giant machines this is the tokamak energy development plan we aim to use small machines to investigate as much as possible and to develop technology before building a pilot plant to demonstrate electricity generation and to show that fusion could be commercially viable by 2030 this is one of tokamaks from 2015 this was the first talked about in the world to have all its magnets made from high-temperature superconductors it was a demonstration of that early May technology we're now working on further high-temperature superconductor development to build bigger magnets for high field tokamaks we also have a new bigger tokamak called st 40 st 40 will investigate how the plasma behaves in this compact high field configuration but we also hope to make fusion temperatures inside this machine a hundred million degrees that's hotter than the center of the Sun which is only 15 million degrees this is a scale drawing of SC 40 you can see the brown magnets around the outside and the pink in the middle that's where the plasma will be now I also have some more pictures of SC 40 from the construction phase so this is the inner vacuum vessel it's the very center of the machine where the plasma will sit then the magnetics are so the magnetic coils go on the outside these ones at copper not superconductor we have currently two parallel development tracks this is the outer vacuum vessel which will enclose a whole machine this is the outer vacuum vessel Halfon and again with a magnetic coil attached and then this is a picture of the inside of the machine you can see the wispy white plasma forming around the coils it just needs to be pushed into the center now the experimental program on st 40 is just beginning we're studying how the plasma behaves in the compact high field configuration we're also investigating a novel method of starting up the plasma and we hope to get fusion temperatures in this machine if we can do it opens up the possibility of compact fusion if we can make smaller tokamaks that also opens up the possibility of factory production and easier commercialization and the modular approach will make the power plant operation more flexible for me this is really exciting because we desperately need the fusion solution to our current energy problem all the work that has gone into jet and Ito means that we have a strong knowledge base on which to build but I believe that it's emerging technologies to hold the key to commercializing fusion talk about energy physicist Allen costley who used to work in ether published some research that says that fundamentally there's nothing in the physics that says that future machines have to be huge his papers in the nuclear fusion journal are the most read ever and you can read them for yourselves on lines but just think about that for a minute nothing in the physics says that fusion machines have to be huge the size of a fusion device depends on the approach adopted on the engineering and on the technologies available and technologies always change don't you think that's a wonderful thought it may be the things we think are impossible are just not possible now if we could do smaller fusion this opens up the possibility of more efficient marine propulsion they could be application in medicine or the hydrogen economy it could even make interplanetary space travel possible now for space travel you wouldn't necessarily need a tokamak design in fact NASA are funding alternative approaches such as a direct fusion concept at princeton satellite systems the potency of fusion means that a fuel planet the size of a grain of sand could produce the same propellant as a gallon of conventional rocket fuel so the potential is huge fusion may be hard and it may have taken a long time to get to where we are now but I didn't see that as a reason to give up and progress is step by step like climbing a mountain because the difficult takes a little time the impossible well that takes a little longer thank you you [Applause]

Channel: TEDx Talks

Views: 29,485

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Keywords: TEDxTalks, English, Science (hard), Energy, Future, Innovation, Physics, Research, Science, Sustainability

Id: gtmqemcErqY

Length: 17min 5sec (1025 seconds)

Published: Thu Apr 19 2018