Feb. 3, 2021

Ep29: Steven Chu 'Nobel Hero talks Net Zero'

This week, we welcome Steven Chu, Professor of Physics and Physiology at Stanford University, and the 1997 co-recipient of the 1997 Nobel Prize in Physics to Cleaning Up. Professor Chu was was the first of two Secretaries of Energy during President’s Obama term as president, the second being Ernie Moniz, my guest on Episode 17 of Cleaning Up. He is now the Chair of the Board of the American Association of the Advancement of Science (AAAS).

This week, we have also made it into the Top 10 Climate Change Podcasts: https://blog.feedspot.com/climate_change_podcasts/


Professor Steven Chu is currently William R. Kenan, Jr., Professor of Physics and Professor of Molecular and Cellular Physiology at Stanford University. He is also the Chair of the Board of the American Association for the Advancement of Science, a non-profit organisation defending scientific freedom and encouraging a collaborative approach in order to serve humanity as a whole.

Professor Steven Chu served as Secretary of Energy under President Barack Obama from January 2009 through to April 2013. Before that, he was leading the Lawrence Berkley National Laboratory as well as being professor of Molecular and Cell Biology, from 2004 to 2009, at UC Berkeley. Prior to this, he was the Francis and Theodore Geballe Professor of Physics and Applied Physics at Stanford University for 22 years starting in 1987. During this period, Chu was a co-recipient of the 1997 Nobel Prize in Physics for his ground-breaking work in laser cooling and atom trapping

Professor Steven Chu is a member of the National Academy of Sciences, the American Philosophical Society, and the American Academy of Arts Sciences, and a winner of the Humboldt Prize.

Professor Chu earned his BA and BSc from the University of Rochester before receiving his Ph.D. in physics from the University of California, Berkeley. Professor Chu has also received over 30 honorary degrees.

Further reading:

Official bio  


US Government Biography  




Nobel Prize  


National Academy of Sciences  


The American Philosophical Society  


SunShot Initiative  


Lawrence Berkeley National Laboratory  


Ex-Energy Secretary Says Fixing Climate Change Is Tough, There's No Vaccine (December 2020)  


Steven Chu Compares Energy Department Loan Program To An Unsedated Colonoscopy (June 2020)  


Steven Chu: Long-Term Energy Storage Solution Has Been Here All Along (June 2020)  



Click here for Edited Highlights

ML  00:11 

Cleaning Up is brought to you by the Liebreich Foundation and the Gilardini Foundation. Hello, my name is Michael Liebreich and this is Cleaning Up. My guest today is Professor Steven Chu. He's a professor of physics and physiology at Stanford University. He's also a Nobel Prize winner in physics from 1997. And he was the first Secretary of Energy under President Barack Obama. The second of course, being Ernie Moniz. Our guest on episode 17 of Cleaning Up. Professor Chu is also the chair of the American Association for the Advancement of Science. Please join me in welcoming Steven Chu, to Cleaning Up. Steven, thank you very much for joining us on Cleaning Up. 


SC  01:02 

Good to be here. 


ML  01:04 

In your honour, I've got my nuclear physics mug, can you see that? 


SC  01:11 

Yes, I can! 


ML  01:12 

The atom on one side and on the other side, it's got all these subatomic particles 


SC  01:18 

And a few molecules. yes and yes mesons, yes. 


ML  01:22 

Can you see that?  


SC  01:23 

Yeah, yes, yes. protons, neutrons.  


ML  01:26 

It's got gluons and up quarks, and down quark, all sorts of things that, but just to kind of the point of which I fade out, because as you know, I'm an engineer, but I was more of a mechanical engineer. So we'll get into some of that, maybe, but, well, if we could start perhaps, what are you up to? Because I visited with you about a year and a half ago, before COVID. And fascinating stuff you were doing but what's taking your time right now 


SC  01:55 

Well, it's a mixture of things on the university research side, it's a mixture. As you may know, since I stepped down from Secretary Energy, went back to Stanford, I started  in few new areas. I'm working with a colleague of mine, Yi Cui, on lithium metal sulphur batteries. Why lithium metal sulphur? Well, if the future batteries are really... EVs are really getting a hold, even 1% or 2% cobalt is deemed too much. And you've got to get rid of the cobalt and nickel is not far behind. So and we are up to our eyeballs in sulfur because of desulphurized fuels. No one's been able to make a lithium sulfur battery because they can't keep the sulfur on the cathode side. And so we're trying a new idea. We're not ready to submit yet but... And so what we're testing is battery and just to tantalise you, it takes in order to go full cycle so 95%-100% to zero and back. So it's well beyond what you normally need to test battery. But we're on 700 cycles. So this is by far a world record already. Because if you go 95 to 20, you know, you're going to be well over thousand cycles. So we'll see, we figured out how, we just published your paper this June on how to get mine lithium from seawater using electrochemistry. The postdoc who worked on the project is now at University of Chicago, and she's continuing this, you need to cycle it again 1000s of times in order to make it commercially viable, but the electricity is negligible. It's it's really... and the material's cheap. So there's some things that I would give it a 50% or maybe higher chance that it could become commercial. Now, if that works, lithium won't be a problem, at least for a couple thousand years. That's not to say we shouldn't recycle lithium for other reasons. But and so and other people are working on that JB Straubel, you know, one of the founders of Tesla is working on that. So there's that. There's also working on ultrasound imaging, new way of doing ultrasound imaging, and so called nonlinear imaging, which turns out to be much more sensitive to tumors as we just got a Chan Zuckerberg grant to get a see, to see if that really can be getting into clinical practice, but it's partly research and partly, you know, moving forward on that. Then finally we're doing new nanoparticle synthesis. I didn't know how to synthesise particles before. Now this is by the way, it's all new. Since 2014, every topic I've hit is something I've never touched before. And that is also working very well, about to submit. We submitted a couple materials, papers, but more importantly, this stuff really works. And so we're able to do biological experiments with it, and what people simply couldn't do before. And so it's all very exciting. That's on my university side, then there's something else. On the other side, I advise some startups and also some bigger companies. Royal Dutch Shell is one and their Science Council and Siemens is another, but also small startup companies, carbon capture companies, a biotech company that is combining robotics with the new powerful gene manipulation with machine learning. Ultimately, to get organisms to make things, bio generated things that could be useful. Now, it's going to be a while before we're gonna make fuel, because you're competing against $40-$50 barrel oil. So you start with higher value products, and believe it or not, things like films for smartphones and electronics, things of that nature. It's exciting, because in this combination of more powerful gene manipulation techniques, and robotics to take out the noise and machine learning, you begin to programme microbes to do things where sometimes about half the genes you put in, you don't even know what they do. So the machine learning the data is picking up patterns, not based on understanding but saying, okay, we don't know really what these genes do, we know what these genes do, we wouldn't have guessed some of them would be important. But all the rest of them? Well, you know, as as you know, many of the genes that have been identified, we simply don't know what they do. Even in human genetics, there are many, many proteins. In fact, one of the nanoparticle things we're doing is we're studying people who have what's called Swedish mutation, which have much higher likelihood of getting early onset Alzheimer's, you can take cells from people and convert them back into neuron cells. And now all of a sudden, you're working with neurons that are from people who have different mutations or alleles have APOE E4 and things like that and compare and look around for what is different in cells from these people versus normal people. Unfortunately, normal people, we all have a reasonably good chance of getting our suffers by the time we're 90. But early onset is much more serious.  


ML  08:15 

Yeah. Yeah. That's a that's a fascinating sort of tour of the horizon and some really exciting new areas, as you say, all new since 2014. Last time we spoke, you also mentioned electrolysis. So nanostructuring so that there isn't the forces against the bubble formation, which was one the things that requires energy input in electrolysis. 


SC  08:39 

That's continuing. I mean, one of the things we've... so we published a few papers, but when you convert the idea into a little prototype to really see if it's going to work. And you're working with graduate students, sometimes they're good at engineering, and sometimes they're not and so... but this person is actually a very good student. I'm not trying to denigrate the person but I have convinced Shell and Siemens both about three or four years ago, to take electrolysis seriously, for the following reason. It's very simple. When electricity is five cents a kilowatt hour, the energy cost is simply more than you can sell this stuff for. Period. Even if CAPEX were zero. If electricity, especially with renewable energy, when you go to 50%, you're gonna have a lot of excess energy. And they're even people like well, that Shell think it'll be one to one and a half cents a kilowatt hour within a couple of... a decade or so. All of a sudden, for example, the production of hydrogen, the cost of the energy is less than the third of everything, and all of a sudden you went from impossible to let's think of more clever ways of doing it. And  so one of the things I was saying about electrolysis is not only in the bubble, it creates internal resistance, because you have to supply energy to expand the bubble, there's something also very important and that is, in catalysis, where you have, let's say, a feedstock that's liquid, like water, and you turn into hydrogen and oxygen. You don't want it to form bubbles for the reason you just described. And so you put the electrolysis on a very inexpensive hydrophobic, that means that it hates water, interface, the catalyst is right there within a micron or two, your hydrogen molecule you look around, you say, do I want to form a bubble? Or do I escape with 5000 times faster diffusion into the gas phase. So of course, that's the route you take that clears out the hydrogen and so, and similarly, on the oxygen side, so just the physics of this what we call mixture of gas and liquid electrochemistry heterogeneous catalysis is one in which you could also have feedstocks like CO2 coming in doing electrolysis, and either forming a liquid phase something or <inaudible> gas phase, this gas liquid interface, right, the surface of a micron is the essential idea. And that's dictated by physics, and it's catalyst agnostic. Right? So someone invents another catalyst - it's great. It's more in the physics of why you want to have this vapour liquid interface. And that I think, has a lot of promise. Now, why do you want to do this? Well, if you think of hydrogen, there's a minimum potential, a certain number of volts per catalytic reaction and the minimum just to get the thermodynamic stuff is 1.23v, electron volts. Most catalysts are not 100% efficient. So there's a little bit of overfitting, hill you have to climb over so their thresholds are about 1.4 volts, but they don't run them at 1.4 volts, they run them at 2.2 volts. Why? Because they want to get the rate up you want, you know, an amp per square centimetre, a milliamp per square centimetre. And so when you have this vapour liquid interface, the hope is that you can run at 1.5 volts, which you use to produce it at 2.2 volts. So that further lowers the cost of energy, you go to a micron scale things, so you make it much more compact. So, these are the engineering things that I think are very, very possible. And it's just how do you execute this? And I'm hoping Shell or Siemens can pick this up and run with it. 


ML  13:20 

And you were saying that you could do it with CO2. So that would be for carbon capture, rather than for electrolysis of hydrogen. That would be... What you are saying is this different catalyst? And you could use it also to reduce the costs and the energy requirement of direct air capture? 


SC  13:36 

Yeah, I mean, fundamentally, if you think about what we've been doing for the last 130 years, we take hydrocarbons, which are loaded with, energy made by nature, and we go energy downhill, and we convert these hydrocarbons into other forms of hydrocarbons. So the whole plastics and chemical industry is based on mostly petroleum feedstocks or natural gas feedstocks. So it's going downhill, then when you have these fuels or sources of energy or plastic. Let's say they're fuels, you burn them. And what do you get? You get carbon dioxide and water. So the lowest energy state at the bottom of the <inaudible> is water and carbon dioxide. Now, if you want to take water and carbon dioxide, and go back up, you've got to supply energy. Now the exciting thing is, in a world of 20 years from now, when we get really good at both generating energy, and we've got to get good at storing energy, then the move uphill, becomes less and less expensive. And so then you can take things that we have an abundance of, you can recycle the carbon dioxide from point sources, cement plants, everything else. Eventually we're going to have to take carbon dioxide from the air. It's almost a given now, but you start with the easy stuff like from a cement plant. Why is it a given we're gonna have to take it? Well, we're at 415 parts per million, we're not going to stay below 450, you know, that's in a couple more, a decade or two, we're probably going to go over 550. And then when you get over 550, you're getting into a pretty dangerous territory, but there's a little bit of time before the polar caps melt. So you're gonna be able to, you're gonna have to get it out of the air, and sequester, put it back underground or mineralize it or do something, and we've got to figure out how to do that very inexpensively as well. 


ML  15:41 

Now, what I'm going to do, if I could, is you know, that's a fantastic sort of opening statement. And there's a number of jumping off points to different topics that I'd love to try to cover. You talked about cheap energy, the cheap electricity, five cents versus one cent, you talked about climate change, and the imperative to get down below, you know, to sort of get back down below 450, and so on. And also some of these kind of very nanoscale or molecular scale of interaction. So we'll come back to, I think, a bunch of those questions. But one thing that is fascinating to me is that you are a professor of physics and also physiology, molecular and cellular physiology. So and obviously, in your earlier career, it was atomic physics, and it was very physics, and then Secretary of Energy, so you'd sort of expect it to be more physics, but physiology? Explain that journey, if you could. 


SC  16:45 

Okay, so that actually started in the late 80s when I was at Bell Labs, and we were doing laser cooling and atom trapping, and then Arthur Ashkin discovered that the same laser trap could hold on to bacteria. So he made this discovery. Fantastic. And so he was awarded a Nobel Prize for this work. I think two years ago, believe it or not, and  


ML  17:14 

You got there first. 


SC  17:15 

Well, we, I got the Nobel Prize for laser cooling and atom trapping. But there's the same physics of the trap. Now, ironically, Ashkin, just passed away, at the age of 98. But all the little pieces of what he invented were there in 1970. Except he missed only one ingredient. And I mean, he knew about the forces, he knew you can hold on to particles. At that time, he was thinking particles, not atoms. Later he was thinking atoms, but wasn't able to technically pull it off. But the one ingredient he missed was when we were doing laser cooling. We tried other traps, they didn't work. And in desperation, we thought about one he proposed. But it was not highlighted. Because it was a laser focus to a really tiny spot, couldn't trap anything, the volume was nothing. So you wouldn't even think of trapping atoms. And then we have this so called optic molasses, this laser cooling. And it took a couple weeks and I said wait a minute, you know, if there's a teeny tiny little trap and you've got an atom that's kind of micron, just a little random walk and it sees this thing and falls in and it gets cool and lands there. And so I said you know this could work. If you turn on the trap, there's one atom in the volume there's a million atoms outside, that's ridiculous. You won't even be able see it. But if it randomly walks around, it's for the same reason you go to, let's say, in a city where there's a bunch of bars on a Sunday morning, and you look around and you don't find people who are drunk and passed out on top of cars, you find them in gutters. That's because its fullest potential. They randomly walk around and that's where they land. And so I said this is going to work. And so, Ashkin said, well, we can do this in water with just <inaudible>. So the water was a poor man's optical molasses, but it's the same, it's a cooling, a water-cooled thing. And so it worked. The other thing worked, everything worked. And it was this realisation that combining cooling with a random walk and you can capture these things so Ashkin discovers it can hold on to bacteria. And then he discovered it can hold on to little organelles inside, things like yeast. And that was great And off he goes and you know clearly biologists were getting interested in this, I was holding all the patents. And so I told Art, that look, if you can hold on to bacteria you can hold on... And maybe if we glue  a little polystyrene sphere, onto a biomolecule, you can hold on to the molecule with this, you can hold on to molecules by holding on to bacteria, and then you could manipulate the bacteria. But that's a natural handle. But you know, let's put in a fake handle. And that worked. And so that was done in 1989-1990. I got sidetracked because I use that technology working polymer physics. But it was very quickly picked up by the biology community. So that started my journey into biology, in the late 80s, early 90s. By the mid 90s, I was looking at other things you could do studying single molecular systems. And so developing other technologies by the late 90s, my centre of gravity was 50/50. And by 2003, or 2004, it was actually more biology. So even before I became Secretary of Energy I had two groups, atomic physics and biology. By the time I was, Secretary of Energy, it was predominantly biology. Right? So in fact, it was the journey had started 20 years ago, 30 years ago. 


ML  21:25 

Fascinating. And I suppose... I was going to ask the question of whether, since you work on those two areas, if you look at the sort of big solutions for climate change, and for some of the big challenges that we face, are they more likely to come out of physics? Or are they more likely to come out of biology? You need things that scale, that go from those, those nano scales up to huge and vast scales? But where's it likely to come from? And then I'm wondering whether that's a stupid question, because the two are so closely... they've sort of...almost no difference between the two? 


SC  21:56 

Well, you know, it's not a stupid question... but you're quite right, anything you do, that really has to scale, especially if it's climate, you know, you should be interested in things, or at least 100 megatons of carbon abate nothing below that, don't bother thinking about because our carbon emissions equivalent is about you know, 40 plus gigatonnes a year. But the things I told you about electrolysis batteries, lithium mine, the heart of that is actually at the nanometer scale. Yeah. And so pay attention to interfaces, being able to... but you've got to make sure it's manufactured very inexpensively. And I have to say that when I go into these areas, I'm not interested really in publishing papers. I won't go into something to get a paper out, if it doesn't have a chance of getting out there. You know, life is short, why bother? Not everybody has that attitude. But maybe it's because I'm getting older. But in any case. Now, on the bio side, that's a harder decision. On the material side, you There are many things we do now at mass scale that could work. The biology side, there are very few things that we make at millions of tonnes of stuff a year. Okay. What do we make millions of tonnes? It's mostly fermentation. Alcohol, soy sauce, MSG, things like that. We make millions of tonnes a year. Yeast is you know, thing that makes the soy sauce, the MSG and the alcohol. And then the question is, can you programme the yeast or other microorganisms to you know, the yeast-making alcohols have been refined over 1000s of years, it's really good. They've even figured out how to make yeast generate alcohol that doesn't begin to turn off or die at 12% alcohol, which is why the wines are now 13.5%, 14% 14.5% which I think is too alcoholic myself. But that's that's an editorial. So then the question is, can you take microorganisms like yeast and turn 92%, which is what they do in alcohol, of their entire metabolic energy into making alcohols. Why should they want to make that? And so it goes back to this startup company I'm part of, it's exactly that. Can you programme these things to get at least up to 90%, 88%-90%. At that point you can have grain elevator size fermenters. And you go to millions of tonnes and there is hope that you can make things like nylons, other fibres using microorganisms that begin to replace the fibres that we used to make from oil. And, and so there again, because when you do that what you're doing ultimately is you're taking CO2 from something turning into some compound with carbon and hydrogen. And the new thing in biology will attack oxygen. Hydrocarbons are just CH you have a much richer template for generating newer products. But the first thing ultimately you want to replace the old stuff, the big bulk stuff, and that's for energy, transportation, chemicals, plastics, structural materials. 


ML  26:13 

You know, you talked about fibre, I think that fibre looks fairly optimistic also various chemical feedstocks, but the holy grail is of course a fuel and not starting with starch or something like that. But starting with, with a lignocellulose or something that nature produces in abundance, or do you think we can go directly from CO2?  Are we going to go via a biomass feedstock? Or do you think we're going to go straight to the CO2 when we when we crack this? 


SC  26:46 

Yeah, yeah, that's tough to call. I think right now, it's more likely to go biomass, ability to break down the lignocellulose much more efficiently...The hydrogen is going to be commercially viable with electrolysis within a decade. Yes. But that's just a start. But to make hydrocarbons is still more uphill energy. 


ML  27:15 

And you need the sea, you got to get this carbon from somewhere. Yes, yes. 


SC  27:19 

And now the carbon... and you want to get it from carbon mini sources or the atmosphere? There's no way we go to zero unless we're grabbing stuff from the atmosphere, either by photosynthesis, or by direct air capture. I don't know if most of your listeners know, but the amount of carbon dioxide that's captured by the crops in grassland regrowth for grazing is more than the carbon emissions of the world. Okay. But most of it 99 point whatever percent gets recycled. And, and, and so if you can take that natural photosynthesis, make substitute products, eventually fuel, substitute products, eventually, most of the stuff... You also will generate some CO2, for example, in the fermentation process. So what do you do? You capture that you stick it underground? Or you mineralize it? One or the other and then that becomes a negative source of CO2? Okay, yeah. And so that's, that's what we need. We need some negative sources of CO2. 


ML  28:31 

And there is some old press coverage from before you were Secretary of Energy about the glucose economy. Was that sort of directionally? Is that consistent with what we've just been talking about? 


SC  28:43 

Well, that was assigned by some reporter, not by me. But but you know, just to remind people, what that meant was, it's photosynthesis. And then you take that photosynthesis into starches or lignocellulose, you convert it to sugars, feed it to microbes, and then let the microbes make what you need to make. 


ML  29:09 

Okay, so glucose was only one of the stages wasn't it? It wasn't the end. Okay. But one of the things during your time as Secretary of Energy that you kicked off something called the SunShot, which is about solar... 


SC  29:21 

I have it. I it's my Wow, it's the Department of Energy swag. 


ML  29:30 

You're actually wearing still a SunShot t-shirt. Hey, I never got a SunShot t-shirt! 


SC  29:36 

I can get it. If you promise to wear, we'll get you one. 


ML  29:39 

Why did I not get this swag? I never got swag. I had to buy my own atomic mug. I got no swag. But let me just read it. There's something actually it's from the DoE's website it says on February 4, 2011, the date that swag was probably released. The Department of Energy launched the SunShot initiative to reduce the total cost of solar energy by 75%, making it cost competitive at large scale with other forms of energy without subsidies by the end of the decade, which would have been 2020. So the year just closed. This cost reduction corresponds to utility-scale solar, costing approximately $1 per watt, or $0.06, or six cents per kilowatt hour, you know, where I'm going with this, right? Making solar energy a possibility for millions of Americans. Now, of course, what we now know is that it went far beyond that. So the SunShot, which will seemed like it is kind of crazy, the moon shot, but it was the sun shot. Actually, by 2020, we've gone under that by a factor of maybe another 75%, instead of doing one 75% cost reduction through the application of technology and capital and scale, you know, lots of Chinese subsidised capital for their manufacturers and so on. It had happened, you know, twice, two lots of 75% reductions. Were you surprised at the speed of the development? Or was that what you were secretly hoping for all along? 


SC  31:15 

Absolutely shocked. When we first were thinking about the programme, we were talking to solar manufacturers, people like Dick Swanson. And they were having a goal that was half of what we were proposing. But we said no, no, no, we think... and it wasn't just an aspiration. When we set up the programme, we had these waterfall charts and said, where could the cost reductions come from and tried to really detail what the map roadmap might look like. And then in our first SunShot symposium or something, Swanson was very nice. He got up there. And he said, when you guys... when I first met with you, he said, you guys are nuts. You must be smoking something. But then we started talking, and I went back and thought about it and said, it's not crazy. It's it's an achievable goal. And so... 


ML  32:13 

And at the time, just to remind the audience, at the time, it was about $0.25 per kilowatt hour. The solar power, levelized cost. So if you ran it as much as you could all year, you get a cost of 25 cents per kilowatt hour, versus something like, what six or eight cents if you're using natural gas or coal. 


SC  32:35 

So part of what we did not anticipate was, as you mentioned, the Chinese over investment, government-subsidised over investment, which drove a lot of solar companies bankrupt, drove the biggest Chinese solar company bankrupt. But the Chinese, unlike the US, the Chinese company just supported, the company said, no, we're not gonna let you go under and sold to parts. Now the industry has recovered, you can now make solar cells at a profit, at some ridiculously low cost. You're selling profitably 50 cents per watt. And there was technology development, there were a few other things you got... made them more efficient, better, cheaper, longer lasting. Now, believe it or not, crystalline solar may be the dominant form. It's because you've figured out how to make that. So it's all these things. And so what the <inaudible>, did this is after I left, they said it's very clear, we're gonna exceed the goal. So they made this new set of goals. But this idea of saying, you know, let's see what can actually be done if you really want to get there. Talk with... start talking to industry, talk to scientists, what are the things... Now, what are the things we wanted to do, which didn't come along fast enough? There were the soft costs. Cost of installation, especially rooftops, the cost of installing solar rooftop in Germany was half the cost in the United States. And it wasn't because of cheap German labour. There wasn't $1,000 licencing fee, you know, because the little municipalities wanted a little cut of the action. You know, so like a permit. There were lots of other things. And so I actually still were Secretary of Energy. I actually got in there and said, look, you know, we have to bring the costs, the solar costs down to where it is in Germany. We look at the technology. How do we find the technology we just kind of film German work crews installing solar rooftop in Germany, they spend half the time. Okay. Same basic type of roof, half the time They've gotten much more efficient. You can, you can do online ordering and licencing and everything. And the only thing you really need to do is when you're about to hook it up, someone's got to go out and make sure it is not going to screw up the electrical system. It's just like when you know, you have a gas heater, the gas company goes and says that's not gonna cause an accident. Okay, that's about it. You don't need anything else besides that last inspection. And I said, and I know you municipalities want income, but why don't you  make your income the old fashioned way with parking tickets and speed traps and leave solar out of this? It actually worked in Massachusetts, it didn't work in California. They realised, oh, yeah, we don't want to <inaudbile, laugh>. Anyway, so we did a whole bunch of other things like that. Now, what I see is we're in a very good space,  wind is getting cheaper and cheaper, because the engineers are getting... and even offshore wind is really plunging. So the next biggest challenge is you've got solar, you've got wind, but they're not on all the time, you know, solar is 30% of time, wind is maybe off the coast of England is actually 50%-60% of time, that's great stuff. But you need energy storage, and it cannot all come from chemical batteries. In fact, the larger scale storage, the storage for several days, in the near term future meaning next 20-30 years will not come from chemical batteries, it's going to come from pumping water in existing dams, uphill pumped storage, which is 95% of all energy storage in the world today. It's very clear if you don't want to double energy costs, even when wind and solar get well below natural gas. As a storage, this can be an issue when you're going 50-60 70% intermittent energy, and so there has to be something else. And it's going to be in one or two forms, it's either going to be storage of heat in a new way. Or it's a mechanical type of storage. Now what I mean by mechanical typeof storage, you take electricity, and you can turn motor with 95 plus percent efficiency, that motor can lift stuff. And we found historically that the cheapest way to lift stuff is to pump water through a big pipe. The round trip efficiency if you're 50 metres up is 80-85% efficient pumping water and all the friction up the hill and then you come back to the turbine. That's actually as efficient as a chemical flow battery. But it's huge as you can get gigawatts of power that way and gigawatt hours. And so anywhere there's an existing dam, put a little holding pond at the bottom of it, and just recycle the water. 


ML  38:07 

And I'm just... I'm surprised because I thought you were going to say that the way to do it is going to be using some form of molecule, some kind of a, you know, 'power to x' type storage. 


SC  38:22 

That is going to be part of it for sure. And height. And so using electricity for hydrogen then hydrogen, at not the 10,000 psi you need for mobility, but lower. So hydrogen will play a role, in possibly in certain types of mobility, but also in stationary storage. Okay. hydrogen, hydrogen is great, right? There's no overhead all the... think of a battery, a lot of that stuff is overhead. And so hydrogen is great. Hydrogen doesn't ship very well, because liquefying it to 20 Kelvin is not a really good option. People are looking at all sorts of things from ammonia, which can be shipped at higher temperatures. And a little bit of pressure. That's all great. It's going to be a mixture of things like hydrogen. Ideally, we still want to get that hydrocarbon for aeroplanes. Okay? 


ML  39:25 

Yes, I mean, aviation is  really tough. But if we stick for a second with the electrical, as well, but the energy system actually as a whole, the mantra. I'm not sure to what extent it was the mantra during your period as Secretary of Energy, but it's certainly associated with the Obama period overall, is 'all of the above'. 


SC  39:45 

Yes. I agree. That was I was... 'all of the above'... I was very sceptical of hydrogen my first year or two. And my last year I said 'no'. Things are changing dramatically and my first year I said something that horrified some of the good hydrogen folks in the Department of Energy, I said hydrogen, it was mostly about hydrogen for mobility needs, it needs four miracles. The fuel cells, which are going to be made cheaper, and so I had no doubt the fuel cell technology will come along. So that was one but that's okay. Then storage, you cannot store 10,000 psi in carbon tanks, it's not that practical. For certain special high use things, yes. But for ordinary home use vehicle - not practical. Distribution system right? You have to have a hydrogen pipeline, the standard steels get brittle. So you need a distribution system and you need cheap power, you need a clean source of hydrogen. So I say, okay, you need four miracles, but that's okay, with three you get to heaven. You get to be a saint, you get to be a saint with three miracles, and the hydrogen people... So, now, what is different? Cheap energy is here. You can actually use electricity to generate locally, if you have electrolyzers, that become practical and cheap. Okay. The fuel cells have made it, in my opinion, you know, there's still economy of scale, and the 5000 hydrogen cars that Toyota makes, we don't really know how much it costs, but my guess is is quarter million dollars per car, they sell 50,000. But that's okay. But when they go to a million cars a year, it's very believable that you're gonna overcome this economy of scale hurdle, just like Tesla. And so the distribution system is ultimately, you know, we do have... it's feasible, it's feasible, whether you use the existing gas pipelines, you're gonna have to line them with some polymer that protects it. Or you just use the righter way and stick a polymer pipe - that part's feasible. And  so hydrogen is going to be part of the solution. 


ML  42:25 

So I agree, it is I've been doing a lot of work on hydrogen. And I suppose the kind of the fifth miracle, though, is it has to do all those things in transportation, is that it has to do all those things cheaper and better than the alternatives. And the alternatives are not standing still, the alternatives are pretty darn good already, you know, I'm sure you've driven electric car and, and they're getting better and cheaper all the time. And I think what's the other... The other area that suggested for hydrogen is heating, where it's kind of six times less efficient than using a heat pump. Because not only do you have losses making hydrogen, but then you don't have the coefficient of performance. And so it just, yeah, I see hydrogen in long term storage, I see it in green chemistry, I see it  in aviation fuel, I see ammonia maybe in shipping fuel and so on. But I just find it very hard to see it beatig the alternative in transport and heating. 


SC  43:22 

So for heavy duty use, rapid refuelling, it's great. You can still fuel hydrogen faster, and you can batteries now, as you say it's not moving. It's still and you know, I do battery research and I'm on the board of a battery company and the goal on both is to get... so the batteries <inaudible> next generation the battery companies are racing to get what is called 1C to 2C charge. That means, for your listeners, that you have a charge 100% to zero, usually though 95% to 15% and then 95% to 15% of that capacity. 1C means can you charge in one hou. 2C means can you charge in 30 minutes, okay? Most of the charging is C over three. Now imagine you get to, just picking a number, 3C. Okay, so that means kind of full useful range in 20 minutes, but the first two thirds actually gets there in about a third of the time. Okay, so if you have a 400 mile range or 350 mile range, you're talking 200 miles in five, six minutes. Five minutes, okay? Now, at that point, the battery's lasting longer than the human bladder. And so you know, you take it in for refuelling, five minutes, you don't mind waiting five minutes. The fuel stations love you to be there for five minutes. Because you've got to kill time, you know, and you go in and buy candy, soda, or whatever, they make most of their profit, turns out. I learned this from Shell, they run their own gasoline stations,  more profit from selling stuff than the fuel. Just like the car dealers make much more profit from repair than from selling the car, which is why they're so afraid of electric vehicles, the repair goes way down. Right, there are gonna be very few oil leaks. And so, so all these things, so it's gonna so you know, still need a storage, a compact storage. But I can see in certain cases where you still have rapid refuelling and volume is not as big a deal. But it's got all these complications. 


ML  45:57 

Yeah, it's wonderful as you're sort of perfectly hedged with your electrolysis research and your battery research. Very well, well positioned between the two there. But just to touch on a couple of other sort of topic areas in the energy space. Nuclear. And obviously, you know, you've got the background, you understand the science better than I suspect, you know, most of us, all of us. What is your sense of some of the, you know, this kind of battle between the existing mega projects, which I believe have been tested to economic destruction, I can't believe that there any more. In the real economics, I can't believe that any more economic in the developing world or in China than they are in, you know, countries where the full economics is revealed by transparency in the market. So Europe,  the US where, you know, they just don't work anymore economically, or haven't in the last decade or so. But is there hope... am I wrong? Number one. Number two, is there hope in the next generation, the small modular reactors or the new configurations or new fuel types? 


SC  47:05 

There is hope, I agree with you the large gigawatt reactors, given all the requirements and what you need to do, and all the key components have to have, you know, down to key bolts have to be traceable. Because of the concerns of safety. I don't think you're going to be able to whisk away concerns of safety because the public sentiment is what it is. Okay. So how do you do this? Well, the hope is that you produce the small modular reactors at a factory, where the quality control is you just stamp them out with you know, 1000s, then the approval process goes down, the safety concerns have to be... We stamp out many, many cars and aeroplanes. There's still safety concerns with cars and aeroplanes. But one can deal with it, but it cannot be one-offs. Every time you build a reactor, you go back to the same thing. You certify the plane, you certify the car, and then you make sure that as they stamp them out that there aren't you know, we still have recalls.  


ML  48:24 

I was just gonna say you know, when you recall some cars, 150,000 people are inconvenience. But if you recall, a big chunk of our energy generating infrastructure, that's going to be pretty disruptive. 


SC  48:34 

Yeah, so the recalls, I just got an airbag, my old, 19 year old car. It was one of the airbags that went under moist air, it could blow up and kill people. So it was a recall, it took several hours for them to replace the airbag. Of course, you're talking to the dealer and they try to convince you that there's an emerging oil leak in your transmission oil and your engine. I said, that's okay. It's 19 year old I drive it 1,200 miles a year, I have a dipstick. And not only that, I didn't tell them and oh, by the way, in my garage, I don't see any puddle of oil.  


ML  49:18 

But that's a little bit different if it is a nuclear power station, you know. 


SC  49:23 

So the question is when you do a recall, you're not going to do a recall. It's been installed. It's a 50 megawatt or 25 megawatt or a 100 megawatt thing. And so you've got to be able to do it on site.  In a way that's seamless, so you can bring it down. But the whole issue of bringing something down and doing, it's a crucial thing. You know, it's radioactive, and that slows stuff up. And so the real issue is if it's something that you're going to have this thing down for months. If it's some, if it's not some exhilarate piece, but it's really in the core, the core of the core, if you use...Something like that, then you've got to have spares, just, you know, think of our electricity systems, you have these massive substation transformers, right. And what people have is those things do break down. And what they have is they have a bunch of spares and you want to standardise those spares. any sane rational transmission distribution system has just a few standard sizes. And if one goes down, boom, it's back in, you're off the grid for a day or two, and then you're on, you're gonna have to do this thing. 


ML  50:49 

And you're optimistic, the modular reactors, if they're made in that way, there's the maintenance, replacement spares system that you talked about, you think that it will be, it will be able to produce affordable power? I mean, it will be in competition with, you know, solar plus batteries, or with solar plus batteries most of the time and a bit of pump storage or a bit of something else. 


SC  51:13 

The answer is no, I'm not optimistic. You asked us if it had a chance. If I were gonna bet on anything, it would be some combination of chemical plus heat plus pumped storage, all those other things. Plus, you know, the pathway for another factor of two in renewable energy getting less expensive, is pretty well, there, it's baked in. And so it becomes energy towards transmission distribution. And these forms of energy storage, so I would bet more on that than nuclear. I think the public fear of nuclear is what it is. 


ML  51:56 

Yeah. Because you say you would bet on the other.  Does that mean you would then starve the nuclear of funds and say, you're probably going to lose, so we shouldn't do it? Or? I mean, I My position is no, I think that's probably where you're coming from is probably right. But I still think, you know, spend a few billion I mean, what's a few billion in the modern economy? To be sure, because we don't have that many, you know, arrows in the quiver. 


SC  52:21 

I agree with you completely. It's just reason why we're spending billions on fusion. Now, if you ask me whether I think fusion will be economically viable, the answer is even less likely. Because, you know, a fusion reactor is not a $10 billion venture. It's a $30 billion venture, commercial fusion. Okay, the liability of that building projects is late a couple of years and $30 billion is economically catastrophic. And so just that alone is I mean, as I began to advise companies like Shell and Siemens, I began to realise that something that costs $10 billion, like the Fischer-Tropsch in the Middle East, that was a 10 billion but had a cost overrun and so it ended up costing 12 billion or 13 billion. A big oil company, like Royal Dutch Shell is <inaudible>. The appetite for investing in 1 billion or 0.1 billion... 0.1 billion is nothing. You think about it, 10 billion you agonise over. And so that's the other thing about these economies of scale, when you go to these huge investments, all of a sudden, the commercial world is very exposed.  


ML  53:45 

So there's a lot of excitement about fusion in sort of startup world. There's I don't know how many fusion businesses. Are you involved? 


SC  53:54 

I'm actually on the advisory committee of one and I watch the others. 


ML  53:58 

Are you on the advisory committee of one? 


SC  54:01 

The one that works out of Oxford. And I watched the others and and I have to say that, I mean, there's the most recent hype is one in which is a much more compact magnetic confinement one. 


ML  54:17 

Right? And the mini Tokamak, I can't remember what it's called. 


SC  54:21 

Yes. Well, again, it has a chance but I tell you one thing that's not in the headlines and that is if it's going to be a commercial reactor <inaudible> incredible neutron flux. And with all those <inaudible> thing, you still have an issue and with the one of the large standard size, one is looking at... It's a materials problem. 


ML  54:50 

Because you end up with hydrogen embrittlement of everything, right? 


SC  54:53 

Right, and the neutron bombardment actually makes the nucleus of the material move around. Okay, so in addition to... that's part of the hydrogen embrittlement, is that but you also, you know, like, someone told me in one year, they moved 100 times, how are you going to get? Okay, so right now the best materials we have, at the fluxes that are anticipated for our large scale fusion reactor was that there's a sacrificial layer of material, that protects it from the outer containment vessel, but the sacrificial layer has to be moved out every five years, seven years, something like that, because otherwise it would just simply crumble. Okay, so that's a lot of downtime, because this is radioactive stuff, short term reactive, you got to stop it, you got to cleanse it out, you got to put it back on. So this is not a weekend operation. This is months of operation. So that's one thing. Now, then you take that and you say, okay, what if you have the smaller reactors, but you want at least 1/10th <inaudible> power size, you know gigawatt? The fluxes become that much worse. But just think of the surface area of the sacrificial layer. People don't talk about that. But it is a really, because they don't even want to talk about the old problem with this standard fusion reactors. 


ML  56:22 

I wanted to get onto the question of science and society briefly. But I got one question. I mean, it's, I feel almost embarrassed to ask what I'm going to, because there is... NASA has now created, a little bit of air cover for me to ask you this question, which is about lattice confinement fusion. And there's a group at the Glenn lab, the Glenn Research Centre, that's published a paper, sort of proper paper about what normally I would have, you know, I've spent my life, most of my adult life thinking of this pathological science. The, you know, they call it lattice confined nuclear reaction, but it's essentially the cold fusion or LENA as it now is, but this is NASA, who have detected it. So they've kind of given it now the imprimatur that NASA has found this effect. Have you looked at it? Or is it just <inaudible> won't go there? It just, it seems like there is something probably years from being useful. But there does now seem to be a body of serious scientists saying, yes, there is some kind of an effect? 


SC  57:34 

Well, I will have to say, first that you can take, I can see where it might, I haven't... First, I haven't, I haven't read about this. So I'm gonna just speak from ignorance of what I know from background physics. You can take an ion, and you can accelerate it, and you can crash it into something and you can create fusion this way. And real fusion. It's not that the thing is as hot as the sun or anything like that. But it's ion collisions. And you can, I can easily see, and this is true of plasmas, which people, you know, want... a bunch of startup companies trying to do that. And so you get the neutrons that really tell you that this is really real fusion. Okay. But none of the things I've seen so far are telling me that this is going to scale. So you know, you're not, if you throw <inaudible>. But that's not enough, right, you need massive numbers. And so I can easily imagine having a lattice in which in nano, nano scale, there could be some ion rapid last minute acceleration things, okay, or just a nano scale, accelerator, you can do these things that will create fusion, that give you fusion signatures. But I just don't know any of the details. And if it's a standard sort of fusion, deuterium tritium, you do get these neutrons that are just, you know, a real pain. And so it would destroy your delicate nano lattice acceleration. 


ML  59:36 

Yes, yeah. And suddenly, it feels like something that's gonna be quite difficult to build. And your earlier point was, if you can't build it, you're not interested. 


SC  59:45 

Yeah. If you don't see a pathway to real deployment, why bother? 


ML  59:49 

But it is fascinating. I keep I would say, you know, a 10th of a 10th of a percent of my attention on it just in case we're all surprised. 


SC  1:00:02 

I'm with you. It's like small modular reactors, you know, on the scale of things a couple of billion a year is nothing. Yeah. Okay. But don't hold your breath. 


ML  1:00:14 

Right. Right. Right, right. And coming to the kind of the role of science. And, you know, you continued to do research while you were Secretary of Energy. And I remember a paper, which was on energy efficiency and standards, the impulse that standards gave to... and how much actually they had saved, you know... people who say, oh, you know, we can't increase the energy efficiency standards, the CAFE standards for vehicles, because it'll cost too much. And I think you produced a very compelling argument and said, no, it doesn't, it actually has saved, how many, you'll probably remember the number... 


SC  1:00:52 

We looked at refrigerators, washing machines and air conditioning. And you always thought, and when you put in an appliance standard, that the cost of the appliance will go up, but the cost of ownership will go down. In fact, before you can mandate a standard efficiency standard, you have to show that the cost of ownership will go down,  which is energy plus the first time costs. And then we looked at statistics of those four things, we just, you know, no theory, just statistics. And what we found is that refrigerators, the cost curve kept on going down, and there were a little glimpse, but it still would go back to the trend line of the cost continuing to go the original <inaudible> energy costs were going down much further. What was surprising was the other three, it actually the cost, the first cost took a knee, every time there was a standard, it actually started going down faster. And it turned out, you know why would the cost, the first cost of an air conditioner go down? Because they had to be more efficient. So the engineers took a blank sheet of paper, designed a better compressor, which means a smaller compressor, which meant a more efficient compressor. 


ML  1:02:19 

But this is straight out of Amory Lovins thirty years ago, you design for energy efficiency, and the capital cost goes down, because that's the only way to get there. And I don't know whether he proved it. I suspect you did a much more robust job. 


SC  1:02:34 

Amory was arguing on a kind of, you know, basis of look at what you have to do. But you can go back and look at the statistics. So it is shocking. And so... I don't know, we thought this was a great discovery. It was a discovery. We submitted to the Journal of Science got rejected. They did send it out to review. And one of the reviewers said, this is amazing and you should be published. The other two, I'll paraphrase what it said, I don't care what these people say. It doesn't work. So I said, what do you mean it doesn't work. They said, well. You know, these are free market economies. So it is impossible to to make a regulation make the first cost cheaper.  


ML  1:03:34 

In these economies, if there's a $10 note lying on the floor, somebody would have picked it up they'll say. 


SC  1:03:39 

That's right. And so then my reaction was... And so Science decided not to publish it. And I said, well, okay, economists are different than physicists. In fact, all the co authors we're all ex-physicists or physicists, and said it doesn't matter what these people say, we know it's not true. And I said oh, so they don't believe in data. They believe in religion. 


ML  1:04:02 

I'll tell you, I was put in mind of... The people who were actually ill with COVID, but telling the doctors and nurses that COVID didn't exist. And I was put in mind of the liberation of the concentration camps in Europe at the end of the Second World War, that the Allies took German citizens into those camps to show them, knowing, maybe they knew human nature better than we do today, knowing that if they did not do that, that it would be denied in the future. I have no idea what the equivalent is, but it just I don't know where we go. But that's... To me that's the sort of thing that's needed to confront... Truth and Reconciliation or something. 


SC  1:04:44 

Well, so what happened in Germany, what happened is, the vast majority of people in Germany realised what they had been doing during Hitler's era was just it happened and it's never gonna happen again. And since World War Two until recently, it was, by recently, I mean, you know, in the last half dozen years, the neo nazis are coming back. And so and I will talk to my German colleagues, who were born in Germany, now here, you know, I work with them at Stanford, and they say no, this will never happen. And this is maybe four or five years ago before you see this resurgence as a reaction to immigration, as reaction to many, many things world trade, you know your economic life isn't getting better. So I think... but science, you know, listening to science, as having something that's should be not political, it is not political, but a basis of facts that one can then try to do something about, we're now talking about many, many other things in society that are part of this, you know, you can debate politically, how much universal health care you want or not. Okay? You shouldn't debate that... you can't pretend that everybody has access to health care, or has equal justice under the law in the US, for example, you just can't pretend that but yet there's a whole sorts of people who say no, no, they're privileged. The pressure or the politically correct talking going on. And you know, they are advantaged over me. Affirmative action, all this other stuff, and so there are many, many things that we have to figure out how to bridge the gap. Now, what happened in Germany, is there was an admission of guilt and national admission of guilt. Okay, that we did something very bad, we don't want it to happen again. And so it's kind of first... So, you know, President of United States has not admitted he had anything... did anything wrong/ 


ML  1:07:10 

Hard to see the wound being cauterised anytime soon. So on that, on that note, maybe we should draw towards a close with a final question about climate change. Are you optimistic at the end of all of this with all the societal, you know, issues we've just touched on, but also the science and the engineering that we've talked about most of this conversation? Are you optimistic? Or are you pessimistic? 


SC  1:07:39 

Oh, but that one, I am truly bimodal. But look, we got lithium ion seawater, there's gonna be plenty lithium for all... I would say that we are going to go over 450, we're gonna go over 550, we may go over 600. Well, we, a mother, you know, necessities, mother invention, this is going to be the mother of all necessities. The scientists and engineers and people will figure out something, it's going to come a little later, much more expensive. Just like the US is now about 400,000 deaths going to 500,000 by March. The world 2 million, there will be a lot of pain, suffering and death and social disorder due to climate change. But now, having said that, does that mean that 10% of the United States is going to die of COVID? No. I hope 1%  doesn't die, but we're in the kind of tens of percent. And so, so I think, you know, lots of bad... lots of social disruption is, if 5 million refugees have made Europe much less stable politically. And putting up walls and fences, I don't know what 50 million or 500 million will do. But I'm pretty sure that's the scale of the amount of climate refugees will be looking at in the coming half century. And you cannot isolate yourself from dislodgement of desperation, you know, that scale, no society is rich enough or have enough walls to kind of isolate itself from that. So those things, so in the end, you know, well, we prevail. I hope so. But it's not without a lot of unnecessary suffering. 


ML  1:09:53 

So if I can paraphrase in summary, then it's optimistic about the technology. Wrenching changes and very difficult changes, but ultimate sort of survival of civilization and the human race not in question. Is that a fair summary? 


SC  1:10:09 

Yes, yes. But, you know, it's more than this. There'll be a lot of climate deaths. And the real issue is whether the economic system will hold together. Right. If you look at Bill Nordhaus, his analysis of you know, the economist at Yale, got a Nobel Prize a couple years ago, where he thinks that the proper price on carbon, not carbon dioxide, but carbon is hundreds of dollars a tonne. Based on his models, which he invented and that was recognised with the Nobel Prize, I think he's become very much in the camp of very concerned about climate change. But is kind of this realist who said is society... and what prices are you gonna pay... if you're willing to double energy prices, we can go a long way today. Right. And I think technology will get it to the point where it will be parity, but that will take longer. Agriculture, still a big deal. We have to figure out  agriculture. Agriculture, grazing land, more than electricity generation in terms of carbon emissions, and yet agriculture can be part of the solution.  


ML  1:11:44 

Nordhaus is sort of talking about, well, you know, the way human society will kind of say, three degrees is okay, we're in it at the moment, there's this sort of phony discussion about one and a half degrees, my suspicion is that we can get to somewhere around two degrees, because I am, I suppose I'm just an optimist. I'm just, I'm a technical optimist. And I also believe that, in the end, I hope some of those social trends will self correct, a little bit faster than 600 parts per million. I'm hoping we'll get that earlier. But who knows. 


SC  1:12:13 

His little book that came out, I don't know, half a dozen years ago, there's a little asterisk somewhere. And these projections and costs and everything, are assuming that the economy doesn't collapse, the society doesn't collapse. So if you go back and look at pick up that book and look at it, there's this little... It says, we're assuming that economic stability is maintained. 


ML  1:12:44 

And I think that's right. And certainly all the work that I've done is on the assumption that you know, you drive down the cost of capital, well, guess what you need capital markets, which means you need civilization to survive for that to work. I want to thank you for the time you spent with me today. And actually, you know, over the years, you've always been very generous in talking with me. And I'm pretty sure that we're going to find a lot of people very interested in this conversation. So I wish you all the best with your research. And I hope that in a year or so I'll be able to come visit you again in Stanford and and get an update on one, two, three, four, five or six of those different ions that you've got in the fire.  


SC  1:13:22 

Okay, well, it's been lovely talking with you. And, you know, good luck in editing this down to whatever size you... 


ML  1:13:30 

We're probably just put it straight out there because it's such a great conversation. 


SC  1:13:34 

All right. All right. Michael, great to see you again. 


ML  1:13:37 

I wish you all the best and stay safe. 


SC  1:13:40 

You too. 


ML  1:13:41 

So that was Steven Chu, Nobel Prize winner, Secretary of Energy, professor of physics and physiology, and master of everything from the nano scale to the societal trend. My guest next week on Cleaning Up is an old business school friend of mine, Claire O'Neill. Claire is a former Conservative MP and Minister of State for Energy and Clean Growth. She's now Managing Director for Climate Change at the WBCSD. That's the World Business Council for Sustainable Development, which convenes global businesses to work on issues around sustainability. Please join me this time next week for a conversation with Claire O'Neill.