Q&A

Is Fusion in
Our Future?
The U.S. is grossly
underinvested in energy
research, says Obama’s
science adviser. And that
includes fusion power

ROGER RESSMEYER Getty Images (fusion); HARAZ N. GHANBARI AP Photo (Holdren)

John Holdren has
heard the old joke amillion times: fusionenergy is 30 years
away—and always
will be. Despite thebroken promises,
Holdren, who early in
his career worked as a physicist on fusion
power, believes passionately that fusion
research has been worth the billions spentover the past few decades—and thatthe work should continue. In December,
Scientific American talked with Holdren,
outgoing director of the federal Office ofScience and Technology Policy, to discuss
the Obama administration’s science legacy. An edited excerpt of his thoughts on
the U.S.’s energy investments follows.
—Fred Guterl

Scientific American: Have webeen investing enough in researchon energy technologies?
John Holdren: I think that we should bespending in the range of three to four times
as much on energy research and development overall as we’ve been spending. Everymajor study of energy R&D in relation tothe magnitude of the challenges, the size ofthe opportunities and the important possibilities that we’re not pursuing for lack ofmoney concludes that we should be spending much more.
But we have national labsthat are devoted—
I’m counting what the national labs are
doing in the federal government’s effort.
We just need to be doing more—and that’strue right across the board. We need to be
doing more on advanced biofuels. We need
to be doing more on carbon capture andsequestration. We need to be doing moreon advanced nuclear technologies. We

Better understanding of fusion reactions could aid indecisions about their practicality as an energy source.

need to be doing more on fusion, forheaven’s sake.

Fusion? Really?
Fusion is not going to generate a kilowatthour before 2050, in my judgment, but—
Hasn’t fusion been 30 years
away for the past 30 years?
It’s actually worse than that. I started
working on fusion in 1966. I did my master’s thesis at M.I.T. in plasma physics, andat that time people thought we’d havefusion by 1980. It was only 14 years away.
By 1980 it was 20 years away. By 2000 it
was 35 years away. But if you look at thepace of progress in fu­­sion over most of that
period, it’s been faster than Moore’s law interms of the performance of the devices—
and it would be nice to have a cleaner, safer, less proliferation-prone version of nuclear energy than fission.
My position is not that we know fusion
will emerge as an attractive energy sourceby 2050 or 2075 but that it’s worth put­tingsome money on the bet because we don’t
have all that many essentially inexhaustible
energy options. There are the renewables.
There are efficient breeder reactors, whichhave many rather unattractive characteristics in terms of requiring what amounts to aplutonium economy—at least with current
technology—and trafficking in large quantities of weapon-usable materials.

The other thing that’s kind of an interesting side note is if we ever are going to
go to the stars, the only propulsion that’s
going to get us there is fusion.

Are we talking warp drive?
No, I’m talking about going to the stars
at some substantial fraction of the speedof light.
When will we know if fusion
is going to work?
The reason we should stick with ITER
[a fusion project based in France] is that
it is the only current hope for producing aburning plasma, and until we can understand and master the physics of a burning
plasma—a plasma that is generating
enough fusion energy to sustain its temperature and density—we will not knowwhether fusion can ever be managed as apractical energy source, either for terrestrial
power generation or for space propulsion.
I’m fine with taking a hard look at fusion
every five years and deciding whether it’s
still worth a candle, but for the time being
I think it is.
To read more of the conversation with John
Holdren—which includes his assessment of
the future of U.S. science policy, the prospects
for continued progress on brain science, andmore—visit www.ScientificAmerican.com/
john-holdren

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