Speaker 1: Welcome to zero. I'm Akshatrati this week red photons, blue
Speaker 1: photons and profiting on sunshine. When you think of the iPhone,
Speaker 1: there's one person that comes to mind, Steve Jobs. Same
Speaker 1: with electric vehicles. Elon Musk looms large, even though the
Speaker 1: industry now extends well beyond him. But what if I
Speaker 1: asked you about the solar panel? Does anyone come to mind?
Speaker 1: Probably not, even though it's one of the most revolutionary
Speaker 1: pieces of technology. We have to reduce emissions. So I'm
Speaker 1: going to offer up a candidate, Professor Martin Green, who
Speaker 1: has been called the godfather of solar.
Speaker 2: We held the world record facilic and sell performance for
Speaker 2: three of the last four decades. The two main competitive technologies,
Speaker 2: which last year count of an ninety percent of the
Speaker 2: world's production, originated in air laboratory in the nineteen nineties.
Speaker 1: Martin Green is a professor at the University of New
Speaker 1: South Wales in Sydney and the director of the Australian
Speaker 1: Center for Advanced photovold Takes. And I want to emphasize
Speaker 1: something he just said, because it's wild. Ninety percent of
Speaker 1: the solar panels produced last year were based on the
Speaker 1: inventions that came out of Hayes Lab. Martin made his
Speaker 1: first solar panel in nineteen seventy one, more than fifty
Speaker 1: years ago. The industry at that point, if you would
Speaker 1: call it, that, was tiny, but it got a boost
Speaker 1: in the aftermath of the nineteen seventy three OPEC oil
Speaker 1: crisis as the US and other countries sought to reduce
Speaker 1: their reliance on imported oil.
Speaker 2: Oh it scranger around for research fund theater research program
Speaker 2: going there that provide additional funding for academics like me,
Speaker 2: So you know, the timing was pretty good.
Speaker 1: With the money, Martin funded a scrappy operation. He combed
Speaker 1: through warehouses in the US and shipped secondhand equipment from
Speaker 1: the microelectronics industry back to Australia. There he and his
Speaker 1: team would assemble the equipment to make the test panels
Speaker 1: and it worked. By the late nineteen seventies, he was
Speaker 1: out competing scientists at NASA to create better and better
Speaker 1: solar cells, the same NASA that had just put a
Speaker 1: man on the moon.
Speaker 2: We were able to cream all these NASA subcontract His
Speaker 2: little Tin Park group in Australia got some international attention,
Speaker 2: which helped us with fundraising and we got a first
Speaker 2: world record in eighty three, so that was an eighteen
Speaker 2: percent efficient cell.
Speaker 1: Efficiency is an important concept in solar but simply it's
Speaker 1: a measure of how much energy from the sun that
Speaker 1: hits a panel is converted into usable electricity. The higher
Speaker 1: the efficiency, the more electricity the panel produces from the
Speaker 1: same amount of sunlight. And this matters because the more
Speaker 1: electricity a panel prity uses, the quicker it pays for itself,
Speaker 1: and the cheaper it becomes relative to other forms of
Speaker 1: electricity generation. While an eighteen percent efficient cell doesn't sound
Speaker 1: all that much, it was a milestone achievement at the time,
Speaker 1: and then year after year, Martin's team beat their own record,
Speaker 1: holding it for all but six months between nineteen eighty
Speaker 1: three and twenty fourteen. This is the first reason that
Speaker 1: Martin is referred to as the Godfather of solar. The
Speaker 1: second is his link to China.
Speaker 2: One of my students, in particular, doctor Jenrong. She was
Speaker 2: fired with this ambition of establishing manufacturing in China, and
Speaker 2: we knew how difficult it be, so I personally tried
Speaker 2: to dissuade him. Just luckily I didn't because we wouldn't
Speaker 2: have the modern industry without his determination to go ahead.
Speaker 1: Martin is responsible for training hundreds of Chinese engineers who
Speaker 1: have gone on to build the vast solar manufacturing capacity
Speaker 1: that China now has. That includes the one he just mentioned,
Speaker 1: Shur jug Rong, who founded Suntech and became the world's
Speaker 1: first solar billionaire when his company floated on the New
Speaker 1: York Stock Exchange in two thousand and five. What Martin's
Speaker 1: team has proved in the lab his students have gone
Speaker 1: on to build and sell around the world. His inventions
Speaker 1: and his lab underpin this vital technology for decarbonization, and
Speaker 1: he is still going strong. So on my visit to
Speaker 1: Australia this summer, I had to sit down with him
Speaker 1: to hear his story firsthand, the crucial role he has
Speaker 1: played in commercializing solar and his predictions for the industry's future.
Speaker 1: Professor Green, welcome to the show.
Speaker 2: Oh, thank you very much, pleasure to be here.
Speaker 1: You are often referred to as the godfather of solar
Speaker 1: and you madea first solar cell in nineteen seventy one.
Speaker 1: Did you go in realizing what kind of impact solar
Speaker 1: could have on the world back then?
Speaker 2: Probably not really, like I think it's only become clear
Speaker 2: over the last five years, perhaps just the huge impact
Speaker 2: that solo is going to have in that it's our
Speaker 2: best weapon we have in fighting climate change. So we
Speaker 2: certainly didn't think that would be the case in nineteen
Speaker 2: seventy one. We thought it might do something useful, but
Speaker 2: it wasn't expecting it would be the key.
Speaker 1: A lot of the inventions that power of the solar
Speaker 1: industry have come from here in Australia, through the University
Speaker 1: of New South Wales, through your work. What is it
Speaker 1: that made Australia such a hub for advances in solar
Speaker 1: at such a large scale?
Speaker 2: Yeah, no, I guess we held the world record facilic
Speaker 2: and cell performance for three of the last four decades,
Speaker 2: so you know, from the early nineteen eighties through until
Speaker 2: quite recently, when you're out in front and you've got
Speaker 2: a critical mass of good people in your team, it's
Speaker 2: easy to stay out in front, I think. And we
Speaker 2: kept working on new ideas and some of them paid off.
Speaker 2: So the two main competitive technologies, both what's now known
Speaker 2: as top con and PERK, which last year count of
Speaker 2: a ninety percent of the world's production, originated in our
Speaker 2: laboratory in the nineteen eighties, so we suggested and first
Speaker 2: demonstrate both of those technologies, but the PERK was the
Speaker 2: one that was first to make commercial impact.
Speaker 1: A solar panel is made up of multiple cells. The
Speaker 1: exact number varies, but it's these cells where the magic
Speaker 1: happens and where Martin's team has made huge improvements to
Speaker 1: increase the panel's efficiency. Martin mentioned PERK, which stands for
Speaker 1: passivated emitur and rear contact. It's a type of cell
Speaker 1: that was first developed in Martin's lab in the early
Speaker 1: nineteen eighties and set a new world record for solar
Speaker 1: cell efficiency in nineteen eighty nine. Very simply put, PERK
Speaker 1: cells work by adding a reflective layer on the back
Speaker 1: surface of the cell, which bounces light back into the
Speaker 1: cell so that more of those photons can be converted
Speaker 1: into electricity. Despite the technology being nearly forty years old,
Speaker 1: it didn't become widely available until the mid twenty tens.
Speaker 1: Since then, it's taken the world by storm, but its
Speaker 1: supremacy is already being challenged by another of Martin's inventions.
Speaker 1: Top con TOPCN stands for tunnel oxide passivated contact, and
Speaker 1: it has the potential to be even more efficient than PERK.
Speaker 1: The tiny tweak it makes to gain that extra efficiency
Speaker 1: is too complicated to explain, even more complicated than the name.
Speaker 1: Until recently, top CON cells have been more expensive to
Speaker 1: make than PERK, but advances in manufacturing mean that in
Speaker 1: twenty twenty four, top CON production is due to overtake PERK,
Speaker 1: according to analysis by Bloomberg NAF so.
Speaker 2: There's now more PERK modules installed worldwide than all the
Speaker 2: solar electricity generation in the history of the human race.
Speaker 2: Is one way I like to look at it. So
Speaker 2: we're very proud of that, obviously, but it looks like
Speaker 2: the next one is going to be top CON, which
Speaker 2: also originates in our lab. We gave priority to BURK
Speaker 2: because it was so simpler technology to manufacture and got
Speaker 2: us to our twenty five percent efficiency target that we
Speaker 2: set back in the eighties and realized in the nineteen
Speaker 2: nineties in our group. So both of those technologies are
Speaker 2: kind to play a big role within the industry over
Speaker 2: the rest of this decade, and.
Speaker 1: A lot of the inventions made in the solar cell
Speaker 1: in your lab in the nineteen seventeen and eighties didn't
Speaker 1: really become commercial until the twenty tenths. Why was that.
Speaker 2: Yeah, there's a number of reasons. One was the industry
Speaker 2: was not really existent, you know, before the twenty first century.
Speaker 2: Back in the twentieth century, it was I used to
Speaker 2: describe it as a boutique industry. So the companies that
Speaker 2: were involved were a lot of them were the oil companies,
Speaker 2: solar companies, you know, part of their public relations activities.
Speaker 2: It wasn't really until the present century that the industry
Speaker 2: got really competitive and switched from being a bow tiki
Speaker 2: industry to a very competitive industry where every possible advantage
Speaker 2: was key the success of the companies involved.
Speaker 1: Now very few people know. And the reason why the
Speaker 1: godfather title is given to you is that many of
Speaker 1: the students that you trained are the very people who
Speaker 1: are now running big Chinese solar companies or powering the
Speaker 1: technology that big Chinese solar companies are deploying today in
Speaker 1: the market. And China is nearly half the world production
Speaker 1: of solar panels today. So how did that come about?
Speaker 2: So, you know, as I said, I guess in the
Speaker 2: twentieth century boutique industry, and it was really my students
Speaker 2: who got interested in manufacturing in China at the turn
Speaker 2: of the century that really created the modern industry and
Speaker 2: made solo selles a reality in terms of being competitive
Speaker 2: in costs and production volumes and so on. But one
Speaker 2: of my students, in particular, doctor Jenrong, she he was
Speaker 2: fired with this ambition of establishing manufacturing in China, and
Speaker 2: we knew how difficult it be, so I personally tried
Speaker 2: to dissuade him. Luckily I didn't because we wouldn't have
Speaker 2: the modern industry without his determination to go ahead.
Speaker 1: Scherzanrong's new venture was Suntech, founded in two thousand and
Speaker 1: one as the first mass market solar manufacturer in China.
Speaker 1: While there had been a handful of small scale solar
Speaker 1: producers in China up to that point, Sure leveraged his
Speaker 1: experience at Green's lab to make punnels that were both
Speaker 1: more efficient and cheaper. He blew his competition out of
Speaker 1: the water, and for several years was the world's largest
Speaker 1: solar manufacturer.
Speaker 2: His progress was noted by US investment banks, you know,
Speaker 2: the big ones like Goldman, Sachs and Morgan Stanley, with
Speaker 2: the two that I'm aware of that got interested in
Speaker 2: getting him to list on the US exchanges. Because Chinese
Speaker 2: stocks were very popular in that era and everyone could
Speaker 2: see it going very well, which it did do, and
Speaker 2: Changroong listed in two thousand and five, only three years
Speaker 2: after his first production of the sales. He listed on
Speaker 2: the New York Stock Exchange, but it was the biggest
Speaker 2: technology flow of two thousand and five, so huge success.
Speaker 2: And Changmong had started his activities with six million US
Speaker 2: dollars raised from local companies, and all of a suddenly
Speaker 2: he got four hundred million US injected into the company
Speaker 2: through this capital raising, and he still owned most of
Speaker 2: the company, so he became the first solar billionaire through
Speaker 2: that listing. But that was really important because it created
Speaker 2: an avalanche of US investment banks looking for other Chinese
Speaker 2: companies they could pass off as a clone of that
Speaker 2: perst successful company. And it also, of course the plenty
Speaker 2: of Chinese companies interested in getting a wind for cash
Speaker 2: injection of four hundred million. So between two thousand and
Speaker 2: five and twenty ten, there were ten Chinese solar companies
Speaker 2: that listed on the US exchanges New York and Nasdek,
Speaker 2: and six of those ten are in the still in
Speaker 2: the top ten manufacturers twenty years after that period, so
Speaker 2: it helped form the backbone of the industry.
Speaker 1: Suntech reached a peak valuation of sixteen billion dollars, but
Speaker 1: by late twenty thirteen, the New York Stock Exchange delisted
Speaker 1: the company after it racked up billions of dollars a
Speaker 1: debt while facing stiff competition from other Chinese solar manufacturers.
Speaker 1: Shure Jianrong was made to step down as chairman and
Speaker 1: the company declared bankruptcy in early twenty fourteen. If you'd
Speaker 1: like to know more about this turbulent period and Solar's
Speaker 1: boom and bus cycles, please listen to our conversation with
Speaker 1: Bloomberg and EF Solar analyst Jenny Chase that's linked in
Speaker 1: the show notes. Now, you mentioned shir Jongrong who created
Speaker 1: Suntach Power, but you trained a number of other students
Speaker 1: in the University of New South Wales.
Speaker 2: Yeah, so, chingong success prompted other Chinese based companies to
Speaker 2: want to get into listing on the USA exchanges, and
Speaker 2: part of the due diligence of the US investment banks
Speaker 2: was making sure they had contact to good technology. So
Speaker 2: because Genrong had come from our group, cruiting people from
Speaker 2: our group became a priority to take a leading technical
Speaker 2: role in the company, so we lost a lot of
Speaker 2: our staff over that period. But it turned out to
Speaker 2: be really important because you know two things. It's lowered
Speaker 2: the cost of solar enormously so that you can now
Speaker 2: talk about it as a viable option in climate change mitigation.
Speaker 2: It also created a huge industry in China, and China
Speaker 2: is installing, you know, forty percent of the world's solar now,
Speaker 2: and that's the country where you already want sold to
Speaker 2: get installed. Otherwise they would be installing more coal plant,
Speaker 2: which is the last thing you want China to be doing.
Speaker 2: So both those reasons, you know, we can feel proud
Speaker 2: that we were able to kick start the industry in
Speaker 2: that way.
Speaker 1: So scientific inventions of these kinds can be hugely profitable.
Speaker 1: There are obviously places where many times entrepreneurs from universities
Speaker 1: benefit from them. Did you ever consider moving from academia
Speaker 1: to business given the kinds of returns you could have got.
Speaker 2: I've started a few spin off companies, but I've enjoyed
Speaker 2: my career in academia because it's been so rewarding, so
Speaker 2: I was never tempted to give up my full time
Speaker 2: job to take on a company activity, although I have
Speaker 2: acted as research directors and so on of different companies
Speaker 2: that have spun off from our group. So I've been
Speaker 2: involved with the industry, but I've never been tempted to
Speaker 2: throw my hat into the ring and become a full
Speaker 2: time industrial participant.
Speaker 1: China's role in the world has also drastically changed over
Speaker 1: the past three decades as its economy has grown so much,
Speaker 1: things have soured a little bit less spit it that way.
Speaker 1: How have you seen that period, especially when you had
Speaker 1: Chinese students come over and then you train them, they
Speaker 1: go back to China and then build this manufacturing capacity
Speaker 1: which other countries now see as a threat because they
Speaker 1: want solar panels, but they don't want to depend on China.
Speaker 1: How have you seen that play out as students have
Speaker 1: come to the university to train on solar technology here
Speaker 1: in Australia.
Speaker 2: Yeah, so Australian universities are quite depended on Chinese overseas
Speaker 2: students because that make up a huge fraction of their
Speaker 2: total budget. So we don't want them to stop coming.
Speaker 2: But there is a chance in the present more aggressive
Speaker 2: Chinese international stance that something like that will happen. But
Speaker 2: you know, the other thing we did was at the
Speaker 2: turn of this century, we created the world's first undergraduate
Speaker 2: degree program in photovoltaic engineering, and about half of our
Speaker 2: students are overseas students from China. But I think it's
Speaker 2: been a good outcome from the world in that it's
Speaker 2: given us the cheap solar cells, and now other countries
Speaker 2: have the chance to get into solar cell manufactur I
Speaker 2: don't think they'll ever be able to match the costs
Speaker 2: in China, but the costs have come down so low
Speaker 2: that I don't think you need to have the absolute
Speaker 2: lowest cost to be competitive with the other options that
Speaker 2: are available. So I'm working with a company in India,
Speaker 2: for example, to try and get them up to manufacturing,
Speaker 2: and I think India has the best prospects of establishing
Speaker 2: a viable industry because they, like China, really need the
Speaker 2: cells and they're quite determined to make a success of
Speaker 2: getting into cell manufacturing.
Speaker 1: Well, that's an interesting way of putting it, because you're
Speaker 1: saying for solar to continue to be a viable industry,
Speaker 1: you don't actually need the cheapest sell. You just need
Speaker 1: to be able to make it effectively in places that
Speaker 1: have a demand for it.
Speaker 2: Yes, I think that's right, because I think the cells
Speaker 2: have overshot in terms of the prices that are required
Speaker 2: to be competitive with what else is out there. You know,
Speaker 2: the International Energy Agency a couple of years ago said
Speaker 2: LA provides the lowest cost electricity in history in some cases,
Speaker 2: and you know the cells are only going to get
Speaker 2: cheaper that you know that overshooting might have been required
Speaker 2: just to convince you know, the more conservative parts of
Speaker 2: the energy industry that you know, the time it come
Speaker 2: to make a switch.
Speaker 1: After the break. Is Martin's work in the lab solar's
Speaker 1: final frontier or is it destined for space? You hang
Speaker 1: out with a lot of people who are in the
Speaker 1: solar industry and you know, people in government surely, having
Speaker 1: seen the kind of work that has led to commercial
Speaker 1: success outside of Australia, there must be feeling within Australia
Speaker 1: that they probably lost out on something, something that was
Speaker 1: invented here that they could have commercially benefited from.
Speaker 2: Well, you know, the way that the technology did get
Speaker 2: distributed was through joint ventures with China, So Australia and
Speaker 2: Chinese joint ventures. So that's the normal way the new
Speaker 2: inventions are brought to market. The invetors set up a
Speaker 2: company and then someone buys them out and the invetors
Speaker 2: cash in on their invention. A lot of my former
Speaker 2: students are a lot richer than I am as a
Speaker 2: result of being brought out of joint ventures in China
Speaker 2: that like. I think the particular circumstances that have got
Speaker 2: us to where we are with sol are the very
Speaker 2: low costs and very active competitive industry results from how
Speaker 2: students wanted to set up in China. So I think
Speaker 2: in Australia you just wouldn't have grown to the same
Speaker 2: size and volume and everything. So I think, you know,
Speaker 2: a bit of a pipe dream to think that Australia
Speaker 2: could have done something in the same part as China
Speaker 2: has done. There wouldn't have been the same interest from
Speaker 2: US investors in investing in Australia as they was in
Speaker 2: China because it was the size of the Chinese market
Speaker 2: that was encouraging that in investment, and the Australian market
Speaker 2: is very small by comparison.
Speaker 1: We had one of our Bloomoginia analysts, Jenny Cheese.
Speaker 2: I don't know if Jenny well so.
Speaker 1: Jenny says that solar manufacturing is very bad business because
Speaker 1: the technology is changing so rapidly that even before you
Speaker 1: make the money on the equipment you have invested in
Speaker 1: to build a particular type of solar cell, the technology
Speaker 1: has changed and you have to bring a new equipment
Speaker 1: and obviously make new investments. Why is it that the
Speaker 1: Chinese are able to be profitable in such a fast
Speaker 1: paced technology environment.
Speaker 2: Well, it's all our team's fault in that my students
Speaker 2: set up the industry in China and they just got
Speaker 2: to a scale that wasn't matched anywhere in the world.
Speaker 2: And then everything they could do in China lowered the
Speaker 2: cost Some of my students used to use a figure
Speaker 2: of three. If they could buy a piece of equipment
Speaker 2: from China, it was going to be a third the
Speaker 2: costs if they bought it from Europe or the USA.
Speaker 2: And now they're doing everything in China. There's a lot
Speaker 2: of movement of people between different companies. They get head
Speaker 2: hundred if they're doing well, so they might only stay
Speaker 2: eighteen months at one company then move on to the next.
Speaker 2: That's quite typical. And then all the equipment suppliers are
Speaker 2: in China and they're only too willing to spill the
Speaker 2: beans on how well their company's competitor is doing with
Speaker 2: their equipment and how they're doing it. And the other
Speaker 2: thing is a lot of the Chinese industry are on
Speaker 2: we chat. There's five hundred of our lumni have their
Speaker 2: own we Chat group, so they know they're talking about
Speaker 2: how well a company's doing and things like that. So
Speaker 2: the information passes around in a way that difficult to
Speaker 2: see it happening to the same extent in other countries,
Speaker 2: and that brings everyone up to best practice very quickly
Speaker 2: and pushes the whole industry on.
Speaker 1: You're still active in research. What keeps you going.
Speaker 2: Ain thing is we haven't done the job yet. As
Speaker 2: an academic, you want to push things to the limit.
Speaker 2: So that's what we did with silicon cells. We thought
Speaker 2: we'd push the limit. We twenty five percent, which we
Speaker 2: got to in ninety ninety nine, was you know, about
Speaker 2: as far as you could practically go. But you know,
Speaker 2: now I'm just doing a paper and suggesting that twenty
Speaker 2: eight percent is where the industry can get to, and
Speaker 2: twenty nine and a half is the absolute limit for
Speaker 2: a silicon cell, So you know, twenty eight percent would
Speaker 2: be probably as far as you can go, although another
Speaker 2: ten years I might be revising that figure upwards. But
Speaker 2: single cell, like a a solar cell sort of like
Speaker 2: a photon converter. You know, a photon with enough energy
Speaker 2: will create one electron in the external circuit. It doesn't
Speaker 2: matter if it's a blue photon or a red photon,
Speaker 2: they still do the same job.
Speaker 1: Photons, the little packets of light that hit solar panels
Speaker 1: and are converted into electricity, have different energy levels. Blue
Speaker 1: photons are full of energy, so much so that they
Speaker 1: can give you some Red photons have less energy. Silicon
Speaker 1: cells are very good at capturing red photons, but not
Speaker 1: so good at catching blue ones. That means a lot
Speaker 1: of potential electricity is not being produced. Martinsteam has made
Speaker 1: cells of different materials that are much better at capturing
Speaker 1: the blue photons. By stacking these cells on top of
Speaker 1: each other into what's known as a tandem cell, you
Speaker 1: can catch both types of photons and create a much
Speaker 1: more efficient solar panel.
Speaker 2: If you can stack a cell that's good at handling
Speaker 2: the blue photons on top of a silicon cell, you
Speaker 2: can get an improvement in performance. You basically sort of
Speaker 2: specializing the cell function so you have a cell that
Speaker 2: can really handle the blue wells stacked on top of
Speaker 2: a silicon cell. It'll grab all the blue photons and
Speaker 2: convert them more efficiently than a silicon cell can. And
Speaker 2: then the red ones who go through to the silicon
Speaker 2: which can convert them quite efficiently. So overall you get
Speaker 2: an efficiency boost from that process.
Speaker 1: And this is called the tandem cell. One after the other,
Speaker 1: and you've built the world record TENEM cell.
Speaker 2: Yeah, so we have a tandem converter actual vaball take
Speaker 2: system that you stick out in the sunlight rather than
Speaker 2: just testing indoors under flashlights or something. But it converts
Speaker 2: forty point six percent of the sunlight falling onto the
Speaker 2: aperture into electricity. So that's presently the world record for
Speaker 2: real outdoor solar conversion by any technique. And that has
Speaker 2: four cells converting different parts of the solar spectrum.
Speaker 1: And is there a theoretical limit to that type of
Speaker 1: cell where you mix different technologies.
Speaker 2: Yeah, under terrestrial sunlight, it's sixty eight percent is the
Speaker 2: theoretical limit. So I don't think we'll get anywhere close
Speaker 2: to that. That requires probably you know, twenty or thirty
Speaker 2: cells stacked on top of one another, but going up
Speaker 2: to six cells in a stack. You get an efficiency
Speaker 2: improvement each time. And you know, the forty percent that
Speaker 2: we're demonstrated, I think is quite realistic type of figure
Speaker 2: to achieve in commerce production. It's not going to happen soon,
Speaker 2: but maybe twenty years down the track we'll have that
Speaker 2: type of efficiency in our commercial panels.
Speaker 1: And you describe that as terrestrial sunlight, which means sunlight
Speaker 1: that is coming to the surface after being filtered through
Speaker 1: the atmosphere. You suggesting that we could have solar in
Speaker 1: space that could be even higher efficiency.
Speaker 2: Yeah, it probably not higher efficiency because the spectrum is
Speaker 2: slightly different in space because of the filtering that occurs
Speaker 2: going through the atmosphere. But you've got more energy in
Speaker 2: space and it's all coming from the same direction. So
Speaker 2: there's some advantages of converting in space if you can
Speaker 2: get the energy back here on Earth, you know, efficiently
Speaker 2: and effectively. The other thing you can do in space
Speaker 2: is get electricity sort of virtually around the clock, you know,
Speaker 2: close to twenty four hours per day. So that's the
Speaker 2: other advantage of going to space. And you know, there's
Speaker 2: a reawakening of interest over recent years in that role.
Speaker 2: But you know, I think terrestrial soil is going to
Speaker 2: be cheap, and you know, there's probably no real need
Speaker 2: to go that direction, but yeah, there might be some
Speaker 2: applications where that proves an effective way of generating electricity.
Speaker 1: Solar panels in space sound like a bonker's idea, but
Speaker 1: it's got some serious minds behind it. In April, the
Speaker 1: European Space Agency commissioned two concept studies for space based
Speaker 1: solar panels as part of its Solarist project, with the
Speaker 1: results due by the end of the year. This is
Speaker 1: not the only breakthrough being pursued in solar so far.
Speaker 1: Most of the episode has focused on solar panels made
Speaker 1: from silicon, but there are a number of other materials
Speaker 1: being explored for making even more efficient solar cells. There's
Speaker 1: a huge bus currently around one technology, in particular, a
Speaker 1: type of solar cell known as a perovskite, named after
Speaker 1: the cell's molecular structure. In recent years, it has made
Speaker 1: the most rapid advancements in terms of efficiency. These cells
Speaker 1: are made from lead based compounds, raising questions aboutxicity. However,
Speaker 1: if they can be commercialized at scale, they have the
Speaker 1: potential to reach even higher efficiencies than silicon based cells.
Speaker 1: I wanted to know from Martin what he thought about
Speaker 1: perovskites and whether they are likely to take silicon's crown.
Speaker 2: Yeah, yes, I've been quite interested in that question. You're
Speaker 2: going back to the eighties, I guess. But silicon has
Speaker 2: four attributes that's very difficult to match in other materials.
Speaker 2: You know, one is an abundancy, you know, it's the
Speaker 2: second most abundant element, neoscruss, and the other is toxicity,
Speaker 2: it's non toxic. The third one is it makes very
Speaker 2: stable material. And fourthly, you can get good efficiency. There's
Speaker 2: only seven materials in total that have demonstrated over twenty
Speaker 2: percent efficiency in converting sunlight, and silicon is by far
Speaker 2: the most stable of those and is the only one
Speaker 2: that takes all those for criteria that I mentioned. So
Speaker 2: there are other materials that have gone into production for
Speaker 2: solar like catiam Tellier is one, which is a compound
Speaker 2: of cadmium, which is a highly toxic, very nasty metal,
Speaker 2: and tullurium, which is very scarce material, like it's even
Speaker 2: scarcer than gold. It's just that no one's really had
Speaker 2: a use for it in the past. You know that
Speaker 2: there's no problem with supply at the present, you can
Speaker 2: see the problem with that technology. It wouldn't be able
Speaker 2: to supply even the present world production of solar. So
Speaker 2: we've been trying to find materials that tick all those
Speaker 2: four boxes. The most promising candidate at the moment is
Speaker 2: perovskite material, but unfortunately it involves lead, which doesn't get
Speaker 2: a clean bill of health on the toxicity front. It
Speaker 2: can give you the good efficiency, so you got very
Speaker 2: big tick in that area, but the stability is the
Speaker 2: main problem. The outdoor environment is really tough and even
Speaker 2: silicon has trouble coping with it in some situations. So
Speaker 2: a material that is at the opposite end of the
Speaker 2: spectrum in terms of stability, it's very hard for me
Speaker 2: to see. Progress has been made, but it's been more
Speaker 2: linear progress, whereas exponential progress. Instability is required for a
Speaker 2: viable products. So we're still looking for other candidates because
Speaker 2: you know, a lot of people are interested in propscites
Speaker 2: and working on it. You have many more than working
Speaker 2: on silicon, I would guess, but I'm not sure that
Speaker 2: that fundamental difficulty will be overcome in time for it
Speaker 2: to have an impact. Hopefully these tandem stack cells will
Speaker 2: come online, you know, sometime around the end of this decade.
Speaker 2: We hold the world record at forty point six percent
Speaker 2: with a lab type process so prohibitively expensive to go
Speaker 2: into manufacturing with that approach, that what we're hoping is
Speaker 2: we can repeat that feat of making a forty percent
Speaker 2: efficient module with technology that slow cost and can be commercialized.
Speaker 1: Well, you've been on the top of the game for
Speaker 1: the past few decades, and I wish you good luck
Speaker 1: to be on the top of the game for the
Speaker 1: next few decades. Thank you for coming on the show.
Speaker 2: Well, thank you very much. It's been talking to you.
Speaker 1: The inventions Martin and his lab have made and his
Speaker 1: students deployed in the Chinese solar industry have made modern
Speaker 1: solar possible. It is rare to have one mind contribute
Speaker 1: so significantly to a world changing technology. Thanks so much
Speaker 1: for listening to Zero. If you liked this episode, please
Speaker 1: take a moment to rate and review it, subscribe on
Speaker 1: Apple Podcasts or Spotify, Send it to a friend or
Speaker 1: to the most efficient person you know. Get in touch
Speaker 1: at zero Power at Bloomberg dot Net. Zero's producer is
Speaker 1: Oscarboid and senior producer is Christine driscoll. Our theme music
Speaker 1: is composed by wonderly special thanks this week to David Stringer,
Speaker 1: Jenny Chase, and Kira bindram i'm Akshatrati back next week