Do we really need fusion?

It does seem as though optimism for fusion has surged recently. But nuclear physicist and emeritus professor at Griffith University in Australia Ian Lowe is much more sceptical of the recent bullish predictions around the future of fusion power…

Ian - It does not seem plausible at all. I remember the standard joke among physicists is that commercial fusion power is 50 years away and probably always will be. In the 1960s, fusion was just a laboratory activity and the achievement of briefly getting out more energy than was put in is a significant achievement in terms of the basic physics. But it's a long way away from being a plausible commercial activity. I haven't yet seen a credible conceptual diagram for how you structure a reactor so that you maintain the plasma at the temperature of millions of degrees, which is needed for fusion to go on at the same time as extracting usable quantities of energy. I don't think it will be commercially realistic in my lifetime.

James - Interesting you say that. So what's caused this excitement, this generated buzz around the topic, do you think?

Ian - Well, what's caused the excitement was that one experiment in which, for a few milliseconds, more energy came out of the reaction than was put in,

James - That was at the National Ignition Facility in America. Just to clarify, wasn't it?

Ian - Correct. And there's been a lot of hype about that, but it's important to remember that while the amount of energy that came out was slightly more than the energy that went in, putting that energy in required the amount of energy that would power a small city. So what we're talking about is an experiment in which the amount of energy that would power a small city briefly produced enough energy to run half a dozen households. Now that's interesting in terms of basic physics, but it's a long way away from being the commercial reality of providing the low carbon electricity we need if civilization is to continue without causing runaway global warming.

James - Well, I suppose then we've got an energy gap to fill, haven't we? We've seen a lot of progress in other renewable energy sources in recent years, solar and wind. Is the sort of buck going to be passed to solar and wind?

Ian - If we're talking about zero emissions by 2050. The easy part of that is getting zero emissions from the electricity supply. It's much harder to decarbonize transport and agriculture and buildings and manufacturing. So we really need to have zero carbon electricity by 2040. And if the earliest that the most optimistic view of when you could have one commercial reactor running is 2040, that just doesn't make any impression at all on the problem.

James - I wonder if you could speak a bit to the deployment difficulties though with solar and wind and that that's been the sort of root cause, hasn't it, of why people have looked at ventures like fusion as somewhere we need to find energy if we're going to, as you say, decarbonize by our ambitious global targets.

Ian - Yes, I suppose there's two points. One is that in the last decade there's been dramatic reductions in the price of electricity from solar farms and large wind turbines. In 2010, the average price of nuclear efficient electricity was about 12 cents a kilowatt hour. Wind was about 14, solar was about 35. Last year, world average prices were 3.70 cents for solar, 4.1 for wind, eight for gas, 11 for coal, 16 for nuclear. So solar and wind are now far cheaper and they're so much cheaper that in the northern hemisphere, large coal and nuclear power stations that have long ago amortized their capital cost are being closed down. The critical point of using solar and wind is that you needed storage because the sun doesn't always shine and the wind doesn't always blow. There's been great improvements in battery technology and pump hydro storage. The other point I'd like to make though is that we shouldn't assume that the demand for electricity is fixed and given. By far the most cost effective way of reducing the amount of carbon dioxide we put in the atmosphere is improving the efficiency of turning energy into the services that we need. The American energy analyst Amory Lovins said 50 years ago, people don't want energy. They want hot showers and cold beer. And we really should be putting a lot more effort into improving the efficiency of the appliances that turn energy into the services that we need, like heating and lighting and electronics, rather than assuming that we need to keep scaling up the amount of electricity that we pour into inefficient devices.

Chris - Ian Lowe. Slightly surprised he didn't mention the fact that, here in Britain, we of course have cold showers in warm beer, but there we are. Imperial College's Brian Applebee is still with us. He made some pretty strong points there. Do you agree?

Brian - Well, I think I would agree with his, you know, assessment that there are a lot of technological challenges and we have to be open to that. And I think it would be very reckless of anyone to assume that fusion energy is going to help us with getting to net zero. You know, there is no way that we can rely on it.

Chris - As in, because it's not gonna happen soon enough.

Brian - Well, it may or may not, but I don't think we can assume it will happen by 2040 simply because there are so many technological challenges that we have not yet tackled. I think we can be confident when we have the time and the resources to tackle them that we will be able to overcome them, but that might take longer than we expect. And so I think he's right on that point. But I think just stepping back from the purely commercial point, you know, it's a challenge worth undertaking because it is such a fundamentally different form of energy. So if we can get it to work, it is game changing.