
Commentaries on Criticisms of Magnetic Fusion [pdf] - theothermkn
https://fire.pppl.gov/fusion_critic_response_stacey.pdf
======
pfdietz
This is all you really need to read from Stacey:

"Based on our present understanding, D-T tokamak fusion reactors project a
cost-of-electricity that is about 50% larger than the projected cost-of-
electricity from advanced light-water reactors in the middle of the next
century."

We all know what happened to the projected cost of fission reactors -- the
projections turned out to be hopelessly optimistic, because of complexity and
loss of experience. Fusion would face these problems in even worse form
(indeed, ITER's cost ballooned 4x or more past the initial projections.)

The experience with fission has enabled us to calibrate the optimism bias in
these projections, with damning results.

Simply being competitive with fission is no longer good enough for fusion to
succeed. It has to be significantly better than fission.

~~~
baking
I think the costs of fission were well understood in 1999. The critics he was
responding to were all taking the position that fusion would not be
competitive with fission.

Fusion is better in terms of proliferation issues, long-term radioactive
waste, and fuel cost. Being in the same ball park in terms of the hard cost of
electricity is probably a good enough target for now.

~~~
pfdietz
It would be good enough, if fission were otherwise the top candidate for
powering the world.

But fission is now a loser technology, hopelessly uncompetitive vs. the hard
charging renewables. It's not even close any more.

~~~
baking
It's never clear what you are really arguing for. Why argue A>B and B>C if all
you are trying to say is that A>C?

Solar with long-term chemical energy storage should play a huge role, but I
think it is too soon to say if one will push out the other or if fission will
stage a resurgence. A lot depends on incentives to phase out fossil fuels. If
natural gas produced electricity remains the cheapest option the development
of all energy alternatives will be effected.

If you are arguing that fusion will never compete economically with natural
gas, you may be right in the short-term but in that case there may not be a
long-term.

~~~
pfdietz
Because that's how you show A > C. Directly comparing fusion and PV would be
difficult, but one can compare fusion and fission (because they share many of
the same elements) and one can compare fission and PV (because they are
directly competing in the actual market).

Fission provides a reality check on believing projections unmoored from
empirical feedback. I would like to see the same methodology for fusion cost
projections applied to fission, to see if the projections are anywhere close
to what the plants actually cost to build in the real world.

~~~
baking
Honestly, I think you are comparing apples to oranges. Average cost overrun
for US nuclear fission plants was 207 percent, primarily due to mid-
construction revisions and additional regulation.
[[https://www.cbo.gov/sites/default/files/cbofiles/ftpdocs/91x...](https://www.cbo.gov/sites/default/files/cbofiles/ftpdocs/91xx/doc9133/05-02-nuclear.pdf)
page 17]

But what you seem to be talking about are cost projections for proposed pilot
plants. It is possible that commercial fusion plants will have construction
cost overruns but most modern fission and fusion proposals incorporate modular
construction to limit the problem of one-of cost overruns.

~~~
pfdietz
> but most modern fission and fusion proposals incorporate modular
> construction to limit the problem of one-of cost overruns.

Let's see how that works out, friends!

"Modular by Design

The AP1000 plant has been designed to make use of modern, modular-construction
techniques. The design incorporates vendor-designed skids and equipment
packages, as well as large, multi-ton structural modules and special-equipment
modules. Modularization allows construction tasks that were traditionally
performed in sequence to be completed in parallel."

Oh dear. Modularization doesn't seem to have helped Westinghouse at all. Sorry
about the bankruptcy, Toshiba!

~~~
baking
Are you saying that fusion plants will face the same regulatory issues that
fission plants experience? Again, I'm not sure what your point is.

~~~
pfdietz
The problem wasn't regulation, it was mismanagement. The complexity of
building the plant simply overwhelmed the firms involved.

Fusion reactors would be even more complex. I think they're well beyond a
practical upper bound for complexity of practical energy sources.

[https://www.reuters.com/article/us-toshiba-accounting-
westin...](https://www.reuters.com/article/us-toshiba-accounting-westinghouse-
nucle-idUSKBN17Y0CQ)

~~~
baking
What do you see as providing the majority of baseline load by 2060?

~~~
pfdietz
There will be no place for high levelized cost baseload generators. There will
be intermittent sources, short term storage, and various chemical fuels
(natural gas with carbon capture, biomass, hydrogen) for long term
variability. Additionally, overproduction w. curtailment, dispatchable demand,
and long distance transmission be used to ameliorate variability of supply.

By 2060, or likely well before, if solar continues down its historical
learning curve, solar should be absurdly cheap, so cheap that resistive heat
will be cheaper than burning any fossil fuel. We might even see artificial
geothermal, where excess power is just dumped into heating rocks and water
underground.

~~~
baking
Current PV factories can only provide about 15% of the total energy need if
they run at maximum capacity over the next 40 years. (Maybe much less if
panels need to be replaced every 20-30 years.) Since the existing factories
are losing money, how can you increase the number of factories by a factor of
seven or more and still get absurdly cheap PV cells? New factories will only
be built if they can justify the capital expense.

Yes PV cells will also get more efficient, but the problem of building all the
factories to produce them and installing the low energy density solar farms,
then storing the energy for daily and seasonal cycles and transmitting it to
the population centers is a hugely wasteful process. Who is to say it is more
practical than fusion. Spending a few billion to explore more economical ways
to generate energy using one of the few methods that nature permits us seems
like a drop in the bucket. If some optimists want to try it, good for them.

Edit: Most of the expanded PV factory production will be best utilized for
industrial processes, further limiting the amount of PV available to replace
baseload. [https://kavli.berkeley.edu/kavli-ensi-retreat-solar-
energy-f...](https://kavli.berkeley.edu/kavli-ensi-retreat-solar-energy-fuel-
generation)

~~~
pfdietz
In an industry with a strong learning curve -- and solar has a strong one,
better than wind -- it makes sense to take near term loses to accumulate
experience.

Applying your same argument, one could conclude nuclear has no chance, since
there is limited capacity to make nuclear power plants, and those making them
have been losing large amounts of money. And unlike solar, there are not good
experience effects there.

Combustion turbines have also shown economic trouble lately. GE's troubles
stem in part from betting on that just before demand started collapsing.

Who says solar will be more practical than fusion, you ask? Extrapolating
historical learning curves, the levelized cost of solar will drop to $0.01/kWh
or so by the time the world transitions to mostly solar, especially in the
sunniest areas. This is vastly lower than the projected cost of energy from
fusion. If you say fusion will show experience effects too, then I'll note
that fusion is most like fission, and fission (as I mentioned above) has not
shown such effects, probably due to the inherent complexity and long
construction time scales.

An ultimate low cost for solar will excuse many sins of variability and
seasonality, allowing wasteful overinstallation and inefficient long term
storage.

~~~
baking
Learn from history. Nuclear power with all its cost overruns and other issues
claimed 15% of the US electric market in 15 years. Where is solar after 40
years?

The difference is building factories to produce cells which are made into
modules that need to be installed in a sunny location, connected to the grid,
and then incorporated into a 24/365 electric demand cycle, versus building a
plant that can produce 100% of its power on day one.

Part of using the learning curve is knowing where you are on the curve. And
remember that it is log-log so you need to keep doubling production to keep
getting those cost reductions (if you don't bottom out against reality.) High-
temperature superconductors are presumably on the starting point of their
learning curve. Increased demands for magnets for fusion research and other
applications along with power transmission devices can potentially drive scale
and efficiency factors for the production of REBCO tape to drive down the cost
measured in $ per A/m.

~~~
pfdietz
No, _you_ learn history.

Where is solar? A factor of 200 cheaper than it was then.

Nuclear has NEVER shown that kind of cost improvement. Its costs have
stubbornly refused to fall. That alone marks it as a doomed technology. The
only question was when the improving technologies would pass it. They have now
done so.

You should pay attention to what the people with the money are doing with
their money. They are, by and large, not building nukes, they are funding
renewables. This is not because they are fools or cranks or green fanatics;
it's because investment in nuclear just doesn't pencil out. It's been judged
in the market and found wanting.

BTW, if you look at the cost figures for ARC, even if the magnets were totally
free the thing would still be far outside the range of economic
competitiveness.

------
mjfl
any more recent commentaries?

~~~
willis936
There would be little benefit. ITER was delayed by 20 years due to a drop of
funding, so most of the primary issues to address have been put on hold. The
plasma physics and machine design has seen progress, but no one has claimed
that wouldn’t be the case.

W7-X’s success has shifted some more funding into stellarators, but outside of
that not much has changed in the landscape in the past 20 years. YCBO is still
prohibitively expensive and fragile, but the use of high temperature
superconductors with high critical currents would increase confinement time by
a large amount.

~~~
baking
Based on YBCO prices from a few years ago, the estitmate was $200M in material
cost for the magnets of a 200MW reactor, not an outrageous amount considering
all of the other costs. The real issue was getting the construction cost of
the magnets down to 2x the materials cost from about the current 10x the
material cost for large superconducting magnets.

~~~
sgt101
The other argument is that if you use YBCO then the overall scale of the
development is orders of magnitude reduced.

