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Lex Fridman Podcast · 4 min · Jul 23, 2025
Fusion and solar are Hassabis's leading energy bets
Demis Hassabis bets on fusion and solar, with batteries and transmission as solar's main constraints. Cheap, clean energy could make desalination and eventually space access much cheaper.
Demis Hassabis is CEO of Google DeepMind and Nobel Prize winner.

Lex Fridman, Host · Host, Lex Fridman Podcast
Robotics and AI researcher at MIT; started the show in 2018.
About this segment
Demis Hassabis bets on fusion and solar, with batteries and transmission as solar's main constraints. Cheap, clean energy could make desalination and eventually space access much cheaper.
From “Demis Hassabis: Future of AI, Simulating Reality, Physics and Video Games | Lex Fridman Podcast #475”, Jul 23, 2025. Watch the full episode
Thanks. We'll look at and fix what's off.
“i think fusion and solar are the two that i i would bet on”
Demis Hassabisat 1:09:07 · Lex Fridman Podcast1:09:07Takeaways
- Solar's constraints are batteries and transmission.
- Fusion depends on reactor design and plasma control.
- Cheap energy could enable desalination and space access.
In this episode
Full episode- 1:57Nature's structure may make hard problems learnable6:56
- 41:03Virtual cells could move much of biology research in silico4:52
- 1:42:18AI may compress a century of change into a decade6:35
- 30:52AlphaEvolve uses search to push beyond known solutions4:56
- 52:06AGI should show consistency and a few unmistakable discoveries5:01
- 37:02AI can solve problems before it can choose the right questions4:18
- 1:24:15AI products should be designed for models a year ahead4:26
1:08:58Fusion and solar are Hassabis's leading energy bets4:03
Transcript
Transcribed by machine (Whisper) from the episode’s audio, so a word may be off here and there.
- 1:09:03
ridiculous question but what what is the main source of energy in like 20 30 40 years do you think it's going to be nuclear fusion i think fusion and solar are the two that i i would bet on um solar i mean you know it's the fusion reactor in the sky of course and i think really the problem there is Is batteries and transmission. So, you know, as well as more efficient, more and more efficient solar material, perhaps eventually, you know, in space, you know, these kind of Dyson sphere type ideas. And fusion, I think, is definitely doable, it seems, if we have the right design of reactor, and we can control the plasma and fast enough and so on. And I think both of those things will actually get solved. So we'll probably have at least, those are probably the two primary sources of renewable, clean, almost free,
- 1:09:53
or perhaps free energy. What a time to be alive. If I traveled into the future with you a hundred years from now, how much would you be surprised if we've passed a type one Kardashev scale civilization? I would not be that surprised if there's a like a hundred year time scale from here. I mean, I think it's pretty clear if we crack the energy problems in one of the ways we've just discussed fusion or or very efficient solar um then if energy is kind of free and renewable and clean um then that solves a whole bunch of other problems so for example the water access problem goes away because you can just use desalination we have the technology it's just too expensive so only you know fairly wealthy countries like singapore and israel and so on like actually use it but but if it was uh cheap then every then you know all countries that have a coast could
- 1:10:46
but also you'd have unlimited rocket fuel you could just separate seawater out into hydrogen and oxygen using energy and that's rocket fuel so uh combined with you know elon's amazing self-landing rockets then it could be like you sort of like a bus service to to space so that opens up you know incredible new resources and domains uh asteroid mining i think will become a thing and maximum human flourishing to the stars like that's what i uh dream about as well is like Carl Sagan's sort of idea of bringing consciousness to the universe, waking up the universe. And I think human civilization will do that in the full sense of time if we get AI right and crack some of these problems with it. Yeah, I wonder what it would look like if you're just a tourist flying through space. You would probably notice Earth, because if you solve the energy
- 1:11:35
problem, you would see a lot of space rockets probably. So it would be like traffic here in london but in space it's just a lot of rockets yes and then you would probably see floating in space some kind of source of energy like solar yeah potentially so earth would just look more on the surface more um technological and then then you would use the power of that energy then to preserve the natural yes like the rainforest and all that exactly because for the first time in human history, we wouldn't be resource constrained. And I think that could be amazing new era for humanity where it's not zero sum, right? I have this land, you don't have it. Or if the tigers have their forest, then the local villagers can't, what are they going to use?
- 1:12:25
I think that this will help a lot. No, it won't solve all problems because there's still other human foibles that will still exist, but it will at least remove one, I think, one of the big vectors, which is scarcity of resources, including land and more materials and energy. And we should sometimes call it like and others call it about this kind of radical abundance era where there's plenty of resources to go around. Of course, the next big question is making sure that that's fairly shared fairly and everyone in society benefits from that.