Why fusion will never happen October 26, 2012

Posted by Maury Markowitz in fusion Tags: fusion power

I like fusion, really. I’ve talked to some of luminaries that work in the field, they’re great people. I love the technology and the physics behind it.

But fusion as a power source is never going to happen. Not because it can’t, because it won’t. Because no matter how hard you try, it’s always going to cost more than the solutions we already have.

Onward brave reader!

NOTE: this article used to contain a lengthy section outlining the tremendous technical issues still to overcome. It had nothing to do with the real argument, so I’ve removed it.

Going over like…

A while back MythBusters decided to take on the task of building a lead balloon. As it turns out, with enough effort, one can indeed make a lead balloon fly.

So now that we have working lead balloons, you should be able to book a flight on one to London any day, right? What, you don’t expect that? Well of course not, because we already have the 747.

Sure, spend a lot of money and maybe lead balloons will get better. But airliners keep improving too. The gap in performance is never going to close. Quite the opposite, because of the fundamental physics of the two, the gap will widen over time.

So I’m pretty happy saying lead balloons for commercial flights to London will never happen. Never ever ever.

And its the very same logic that lets me conclude fusion will never happen. Not so much on the technical grounds, which may very well never cross the enormous gap to commercialization. No, this is about the bottom line.

Even if the engineering is someday fixed, it’s clear to everyone outside the fusion world that the economics will never be competitive.

Not now. Not in 20 years. Not ever.

How the power industry works

It’s easy to think that power generation is a technical issue, that once you build the working gazeza box everyone will start building them. This simply isn’t how it works.

There are three groups involved in building a power plant, and a design has to make all three happy.

First, and most obvious, is the power company. They really don’t care about technology. Their only concern number called the Levelized Cost of Electricity, or LCoE. LCoE basically tells you how much you have to charge your customers for the power generated by the plant. That number has to be similar or lower than the price you can buy it from other plants. There’s no point building a plant if your customers are going to buy the product somewhere else.

The power company operates the plant, they don’t build it. The plant will be built by an engineering firm like SNC-Lavalin. They don’t give a crap about the technology or the LCoE, the only thing they care about is making a profit building it. Is this a machine that lots of people have built before and is well understood? No problem. A new concept that no one really knows much about? You’re going to have to pay them a lot more.

And finally, and most important, are the bankers. They don’t give a crap about the power company’s profitability or the construction company’s, they only care about their profitability. And that is 100% based on the interest they can charge the power company and the risk that the company will default.

Right now the nuclear power industry is dying a horrible death everywhere in the western world. That’s because the bankers won’t pay for it. There is no other reason, regardless of what you might hear to the contrary. No, it’s not because of some patchouli-scented tree-huggers or a global conspiracy of anti-nuclear government agencies. It’s the bankers.

You can’t blame them. A fission reactor at an existing site takes 4 to 6 years to build, during which time you make no money. Reactors at new sites generally take 10 to 12 years. Meanwhile, wind turbines go from the first sketch on a napkin to on the grid in 18 months or less. Consider the decision that a banker has to make when presented with two pitches:

I want 10 million for 18 months, after that I’ll pay you 6% I want 25 billion for 5 years, after that I’ll pay you 8%

Option 1 gets the money every time. Not in theory. This is clearly what is happening in the real world.

You can argue the technical superiority of fission over wind all you want – in fact, it’s pretty much all true. It is a fact that wind cannot be dispatched while nuclear has a CF around 90% and provides all sorts of baseload. It is a fact that nuclear takes up less land than the equivalent in windmills. Add any of the other advantages you’ve heard, they’re probably true too.

Here’s the problem with all of those arguments: the bank doesn’t give a crap.

So the places that are building nukes are invariably where the local government is willing to put up the money, generally interest-free We have new reactors in China and Korea, and everyone else is doing basically nothing. Actually, in the US all the money is backed by the government, and the companies have ignored it anyway. It’s just too expensive and economically risky.

Let’s talk actual plants

Let’s take a quick look at how power plants work. Generally, you’ll find that you can break them down into three general classes:

direct conversion direct burning or turning heat engines with a steam turbine

The first group currently contains only one member, large-scale PV solar plants. Light falls on them, electricity comes out. It’s not perfectly direct, you have to convert from DC to grid standard AC, but by any measure, PV is the simplest form of large-scale power available today.

The next group are those forms of power that use a turbine that is directly powered by its fuel. Hydro is a good example; water goes through the turbine, the turbine spins a generator, power comes out. This class also includes wind generators, geothermal and natural gas plants. These systems have moving parts and are thus more complex to build and maintain than PV, but generally offset those costs through the density of the power which lowers relative construction costs.

Finally, there’s the last group, the classic power plant. These consist of some sort of heat source – coal, gas, nuclear or even solar in some cases – which boil water and then use that to drive a steam turbine. These tend to be very compact and save money on land and construction, but offset that because they’re more complex.

Now here’s the thing: the turbine in the heat engine case is basically the same price as the one in a gas plant, watt for watt. But a heat plant isn’t just a turbine, it’s all the other stuff too.

If you look at any plant in this last group, you’ll notice that the building is always in two parts, the “burner” section generating heat, and the turbine hall. And the burner part is always bigger.

All of this means that classic heat-engine power plants are always more complex than other forms of power. Now complexity doesn’t always turn into price, but it often does, and almost always does in industries that squeeze the systems for efficiency. And the energy market has squeezed. Hard.

This shouldn’t be surprising, really, but many people refuse to believe it. So let me just list a couple of examples of how much it costs to build a watt of generation, taken from Version 8 of Lazard’s LCoE tables:

Solar PV, $1.25 to $1.75 per watt-peak (Wp)

Wind, $1.40 to $1.80 per Wp

Combined cycle gas, $1.06 to $1.32 per Wp

Coal, $3.00 to $8.40 per Wp

Nuclear, $5.39 to $8.30 per Wp

So here’s why no one builds nukes anymore

To put this in perspective, let’s examine the nuclear plant example.

Overall a nuclear plant is a lot like a coal plant – there’s the reactors on one side producing heat, and then there’s a turbine hall generating power from that heat. In the industry lingo, the entire reactor side is known as the “nuclear island”. That part makes up about 1/3 of the price of the system as a whole.

That means that if you take the average price for modern reactors, $7.60, about $5 of that is non-nuclear. Which is important. Because that means that even if the reactor were free, the plant as a whole would still cost more to build than a wind turbine.

Not just more, three times more.

I know, I know, the power from that reactor is almost 24/7 and you can’t rely on wind. Go tell it to the only person that matters – the banker. Let me know how that goes.

Ok, fusion

The basic argument I’m making is that if the bankers aren’t willing to fund fission, because it costs too much and takes too long to build, then they’re definitely never going to fund fusion.

To understand why, consider that a fusion plant is basically the same as a fission plant, but with a different reactor. All the other parts, the heat exchangers, turbine hall, etc. is the same. So we need to understand how a fusion reactor might compare to a fission reactor in terms of design and economics.

It’s tough to say exactly how much a fusion reactor will ultimately cost, because we can’t make one that works. But that just means there’s no limit on the upside price. We can make accurate predictions of the lowest possible cost in the best case scenario. So let’s do that.

What we know is that any sort of fusion plant will be fantastically complicated, orders of magnitude more complex than a fission design. It is filled with incredibly complex machinery for fueling and tritium extraction, all sorts of heating systems, ridiculously expensive superconducting magnets and all their cryogenic support machinery, the heat extraction system which has to be built in two separate parts (some of the heat goes into the lithium blanket, some doesn’t) and complex control systems.

Now once we’ve built it, we then have to put the whole thing into a ridiculously good vacuum state, or it just won’t work. And that costs a freakish amount of money.

And then there’s the lithium. We need lots of it to get tritium breeding. Lots as in at least a 1 meter thick layer lining the entire reactor core (the red part in the diagram). That’s maybe 10,000 tonnes. Lithium is selling for about $7/kg, but that’s mix of the Li-6 we need and the Li-7 that is most of what we get. Realistically, we’re looking at prices around $180/kg (see notes) which represents a cost-per-watt of $1.8/W in this design.

That means the lithium alone is more than the cost of a wind farm that produces the same amount of energy.

And that’s for one raw material out of hundreds. And the rest are even more expensive. Superconducting magnets? Ugh.

And then on top of that, the energy they produce is so diffuse, you need huge plants so even the cost of construction will be enormous. The diagram is the baseline design for the DEMO reactor. If you look carefully, you can see that this cross section is about 20 m high and 12 m across. A reactor would consist of many slices like this, arranged in a ring that would be about 30 m across. This is just the pressure vessel, the reactor as a whole would be many times larger.

For comparison, the General Electric BWR power reactor has a core that is about 8 m across and 21 m high. In other words, this single slice of the DEMO is larger than a BWR’s entire core. A complete DEMO core would require an enormous containment building. One can judge by ITER, a sub-scale version of DEMO; ITER’s floor alone consumed 220,000 cuyd of concrete, and at current prices that’s 15 cents/watt just for the floor. That’s 1/10th the cost of the entire wind farm. For the floor. The floor.

Now back to the start… no one would build a fission plant today even if the reactor were free. A fusion reactor will always, always, cost way more than fission.

Really, never?

Now here’s the key point I’m trying to make: it’s not that fusion is expensive, it’s that everything else is cheaper. And the last thing anyone needs is a more expensive form of power. We already have an infinite variety of those.

Imagine some future where we’ve covered the entire surface of the planet with wind turbines and we still want more power. Then we’d use fusion, right? No! We have hundreds of other sources that are also completely renewable that we already don’t use. We’ll just pick one of them. Then the next one, and the next. Fusion is somewhere like #100 on the list.

I know at this point you’ll dream up some reason why fusion might get cheaper. So maybe you think it could move down the list from 100 to 10. But the fundamental problem is that most of the ways that could happen would make other things cheaper too.

So, for instance, if you come up with a way to build a steam turbine for half as much money, you do indeed lower the cost of making a fusion plant. However, you’ve also lowered the cost of making a fission plant, and a coal plant too. You’ve probably lowered the cost of a gas turbine as well, and maybe even wind. So you’re in exactly the same place you started, everything else is still cheaper.

Now there are some parts of any power plant that are unique, like the fibreglass blades on a wind turbine or the superconductors in a fusion plant. Ok so let’s say you argue we could lower the price of those superconductors to make the fusion plant cheaper relative to wind. But look at the math; in order for this to make it cheaper than wind, those superconductors have to cost negative dollars.

I’m not methuselah, but I’ve lived long enough and not once did I see a power plant that cost negative money.

We’re not going to fly lead balloons commercially. There is always going to be other solutions that are better, and we already have them. And we’re never going to use fusion for widespread commercial power. There is always going to be other solutions that are better, and we already have them.

So that’s why I say “never” and feel very safe doing so. But I’m not really saying it, because…

Everyone knows this

According to the fusion supporters, the price of power keeps going up, and sooner or later the price of all this engineering will become worth it. Here, let’s quote the guy that runs MIT’s fusion efforts:

It depends on what the price of oil is going to be 50 years from now

Well, no, it doesn’t. Fusion reactors don’t produce oil, they produce electricity. And we have lots of other ways to produce electricity. And lots of those are cleaner, cheaper and actually work. But most importantly, the price of those systems keeps going down, not up. Fusion is becoming less and less attractive as I write this. Literally.

And it’s not like this isn’t widely known. Sure, the materials produced for the industry fanbois doesn’t mention this, but 15 seconds in Google will find everything you need to know about the reality of fusion power. Here’s one good summation:

Scaling of the construction costs from the Bechtel estimates suggests a total plant cost on the order of $15 billion, or $15,000/kWe of plant rating. At a plant factor of 0.8 and total annual charges of 17% against the capital investment [ed: principle paydown and interest], these capital charges alone would contribute 36 cents to the cost of generating each kilowatt hour. This is far outside the competitive price range.

Far outside indeed. Hydro is between 1 and 2 cents, wind around 5, NG 4 to 6 depending on the model, PV around 6 to 10. In other words, construction costs alone will mean that fusion will never be competitive with current sources. (UPDATE: in 2016 these numbers are down to around 4 cents for wind or PV)

The nuclear industry periodically produces reports that estimate what sort of price they predict out into the future. In a relatively recent study, found here, you’ll see on page 4 that the price of energy from fusion remains higher than any other source even when you predict out 100 years. And I would suggest that the numbers in this document are being really optimistic in terms of the reductions in CAPEX possible in a fusion plant.

Practically everyone outside the fusion labs is fully aware of the problem, have been since the 1980s, and are becoming increasingly vocal about it. As Michael Dittmar of CERN puts it in the conclusion of his excoriating review of the remaining problems:

However, among those who are not part of ITER and who do not expect miracles, an ever increasing number of scientists is coming to the conclusion that commercial fusion reactors can never become a reality.

Note the “never” part, yet another reason I feel safe in my conclusion.

In 2012, Robert Hirsch, who used to run the U.S. fusion program, stated it clearly:

First, we have to recognize that practical fusion power must measure up to or be superior to the competition in the electric power industry. Second, it is virtually certain that tokamak fusion as represented by ITER will not be practical.

So then…

The basic argument for fusion from the start was that electricity prices will keep rising, and all of our existing sources will eventually run out.

But that didn’t actually happen. Usage eventually reaches a slow rate of growth that we can easily make up with existing sources. And as a result, existing sources were put through the wringer to squeeze out the costs. PV has fallen in cost over 100 times. Fusion, meanwhile, keeps getting more expensive.

No, I’m not saying we should use wind and PV for all our power. But what I am saying is that the very niche that fusion advocates suggest makes that power source so great can be filled with sources that we have today and are far cheaper. Why would anyone want to spend a lot more money to get the same thing?

I fully support a pure research program for radically different approaches to fusion, but any money spent on the baseline approach like ITER is simply throwing good money after bad. The final word to Dittmar:

It is late, but perhaps not too late, to acknowledge that the ITER project is at this point nothing more than an expensive experiment to investigate some fundamental aspects of plasma physics. Since this would in effect acknowledge that the current ITER funding process is based on faulty assumptions and that ITER should in all fairness be funded on equal terms with all other basic research projects, acknowledging these truths will not be easy. Yet, it is the only honest thing to do.

Here’s some light reading on the topic