is when are we going to get fusion it's really
that that's why the sun shines i've always been very worried about resource i don't know about you but when my mother gave me food
i always sorted the ones i disliked from the ones i liked and i ate the disliked ones first because the ones you like you want to
as a child you're always worried about resource and once it was sort of explained to me how fast we were using up the world 's resources
i got very upset about as upset as i did when i realized that the earth will only last about five billion years before it's swallowed by
big events in my life a strange child
country oil gas
sorry gas i'm probably the only person who really enjoys it when mister putin turns off the gas tap because my budget goes up we're really
it's really from knowledge
if you look fifty years into the future the way we probably will be making energy is probably one of these three with some wind with some other things but these are going to be the base load energy
solar can do it and we certainly have to develop solar but we have a lot of knowledge to gain before we can make solar the base load energy supply for the world
put in six new nuclear power stations and probably more after that china is building nuclear power stations everybody is because they know that that is one sure way to do carbon free energy
but if you wanted to know what the perfect energy source is the perfect energy source is one that doesn't take up much space has a virtually inexhaustible supply
is safe doesn't put any carbon into the atmosphere doesn't leave any long lived radioactive waste it's fusion
but there is a catch of course there is always a catch in these cases fusion is very hard to do we've been trying for fifty years
okay what is fusion here comes the nuclear physics and sorry about that but this is what turns me on
i was a strange child
and you can get energy out this way and indeed that's exactly what stars do in the middle of stars you're joining hydrogen together to make helium and then helium together to make carbon to make oxygen all the things that you're made of are made in the middle of stars
but it's a hard process to do because as you know the middle of a star is quite hot almost by definition
and there is one reaction that's probably the easiest fusion reaction to do
it's between two isotopes of hydrogen two kinds of hydrogen deuterium which is heavy hydrogen which you can get from seawater and tritium which is super heavy hydrogen
these two nuclei when they're far apart are charged and you push them together and they repel but when you get them close enough something called the strong force starts to act and pulls them together
so most of the time they repel you get them closer and closer and closer and then at some point the strong force grips them together
if you can get something to about one hundred and fifty million degrees things will be rattling around so fast that every time they collide in just the right configuration
this will happen and it will releaseenergy and that energy is what powers fusion and it's this reaction that we want to do there is one
else and you make if from lithium that reaction at the bottom that's lithium six plus a neutron will give you more helium
plus tritium and that's the way you make your tritium but fortunately if you can do this fusion reaction you've got a neutron so you can make that happen
now why the hell would we bother to do this this is basically why we would bother to do it if you just plot how much
fuel we've got left in units of present world consumption and as you go across there you see a few tens of years of oil the blue line by the way is the lowest estimate
tens of years and perhaps one hundred years of fossil fuels left and god knows we don't really want to burn all of it because it will make an awful lot of carbon
and then we get to uranium and with current reactor technology we really don't have very much
this is a bit shocking because in fact our government is relying on that for us to meet kyoto and do all those kind of things to go any further you would have to have breeder technology and breeder technology
is fast breeders and that's pretty dangerous the big thing on the right is the lithium we have in the world
and lithium is in sea water that's the yellow line and we have thirty million years worth of fusion fuel in sea water everybody can get it that's why we want to do fusion is it cost competitive
we make estimates of what we think it would cost to actually make a fusion power plant and we get within about the same price
as current electricity so how would we make it we have to hold something at one hundred and fifty million degrees and in fact
we've done this we hold it with a magnetic field and inside it right in the middle of this toroidal shape doughnut shape right in the middle is one hundred and fifty million degrees
it boils away in the middle at one hundred and fifty million degrees and in fact we can make fusion happen and just down the road
this is jet it's the only machine in the world that's actually done fusion when people say fusion is thirty years away and always will be i say yeah but we've actually done it
but that's not really fusion power that's just making some fusion happen we've got to take that we've got to make that into a fusion reactor because we want thirty million years worth of fusion power for the earth
this is the device we're building now it gets very expensive to do this research it turns out you can't do fusion an a table top despite all that cold fusion nonsense right you
you have to do it in a very big device more than half the world 's population is involved in building this device in southern france which is a nice place to put an experiment seven nations are involved in building this it's going to cost us ten billion and we'll produce half a gigawatt
fusion power but that's not electricity yet we have to get to this
we have to get to a power plant we have to start putting electricity on the grid in this very complex technology and i'd really like it to happen a lot faster than it is but at the moment
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