• Untapped solar rooftop potential costing Australians billions each year: new report
• Could spending a billion dollars actually bring solar production back to Australia? It is worth a shot
• Bigger and better solar panel recycling centres needed to deal with PV waste, says report
• Solar panels in your eyeballs? This engineer is looking into it
• Climate change will impact how fast PV modules degrade: new study

Voiceover | 0:06

Welcome to UNSW's Engineering the Future podcast, a series where we'll speak to academics and industry leaders who are embracing cutting edge ideas and pushing the boundaries of what is truly possible. In this episode, we'll shine a light  on the exciting developments in the solar technology industry, and discuss what impacts we can expect on society as a whole. Over the next two decades, we'll hear from leading experts in the field, Professor Renate Egan, and Dr Zi Ouyang as they share the roadmap to how Australia will achieve 100% of its energy from renewables. With half of that from solar technology. They'll also reveal the innovative ways the industry is using to capture, buy and sell solar energy, and how researchers are collaborating with industry leaders to improve the efficiency of existing and new solar cell technology. So join us as we discover how world changing action starts with fearless thinking in engineering the future of solar.

Neil Martin | 1:10 

Hello, and welcome to Engineering the Future of Solar. My name is Neil Martin, and I'm a journalist and STEM communicator working in the Faculty of Engineering at UNSW. Joining me today to discuss what changes we can expect in the development of solar power over the next 30 years is UNSW Professor Renate Egan, Executive Director at the Australian Centre for Advanced Photovoltaics. Renate spent two decades in the PV industry, where she led manufacturing and technological development, and her research now includes assessing new technologies for their commercial viability and impact on energy markets. As an innovator, entrepreneur, and academic, Renate is passionate about using her skills to increase the uptake of solar and accelerate the energy transition. Hi, Renate.

Renate Egan | 2:02 

Hi Neil, Thanks. It's terrific to be here.

Neil Martin | 2:04 

It's a pleasure. Also with us is Dr. Ouyang, Vice President and Chief Technology Officer of JA solar, a world leading solar module manufacturer. Ouyang is a researcher, manager and entrepreneur, with 20 years experience in clean energy research, and technology commercialization. His goal is to help develop green energy technologies that can make the world a better place to live. Welcome, Ouyang, [Hi Neil] Now 44 quadrillion watts of power. That's the amount of energy hitting the Earth each year from the sun, according to NASA. Or to put it another way, the equivalent output of more than 40 million large electric power plants. Luckily, for the global population, that source of solar power won't run out for billions of years. We're not looking that far into the future on today's episode, but just as far as 2050, when the major goal is to reach net zero greenhouse gas emissions, in order to avert the worst impacts of climate change. Solar energy obviously has a huge potential role to play in that. But currently, only around 14% of energy produced in Australia comes from photovoltaics. Renate, starting with a very direct question to you. What percentage of energy produced in Australia do you think will be from solar, if we look ahead to 2050?

Renate Egan | 3:32 

To 2050... so by 2030, it's already ahead of the numbers, the 2023 numbers have just come in. And we're much closer now to 20% of our electricity, being met by solar for the year of 2023. By 2030, the targets are to be at over 80% renewables and we would expect 40% of that to come from solar. By 2050, we will be looking at 100% renewables and we would expect over 50% of that to come from solar 50- to 60% of the electricity needs will be met by solar. And our electricity needs are going to grow because we need to electrify everything. So all of our thermal processes where we rely on gas and all our transport processes where we rely on fuel, we'll be switching to electric.

Neil Martin | 4:22 

You must be very enthusiastic about those potential numbers and the growth in solar. Does it surprise you in some way?

Renate Egan | 4:31

The industry keeps surprising me because it's growing at a phenomenal rate. The last 20 years has been really exciting. And I think the next 20 years are going to surprise everybody. And in fact, how quickly it's growing is really important to communicate. Because we're all going to see that change in the next 20 years. We will see that reduction in the use of gas, reduction in the use of fossil fuels coal burning, and we need to get used to that and to understand as a community what impact that's going to have on our lives.

Neil Martin | 5:02

Ouyang, that was the stats. They're really up to date stats, thank you Renate for updating my numbers. Those are the stats for Australia, do you see the same potential growth in numbers for the global industry?

Zi Ouyang | 5:17

Yeah, I think relatively at the same pace. But I think actually, Australia is ahead. So the penetration of green and renewable energy is actually ahead of the rest of the world, if not the best, and it's one of the best. So we actually technologically experiencing something that the rest of the world hasn't been seeing. So that's great. That's why we have our leading research here in the university, and the institutes because we, the first country actually experienced a lot of chances as well as challenges.

Neil Martin | 5:53

And is the reason for that the fact that Australia has lots of nice sunshine, and maybe quite a lot of space to put solar panels?

Zi Ouyang | 6:01 

Yeah, I think so.

Renate Egan | 6:02

And I think Australians get the sun. So we have more solar on rooftops in Australia, than anywhere else in the world. And we have more solar per capita than anywhere else in the world, Netherlands is coming close, they might just beat us because we've had a bit of a bit of a slow year in 2023, for new installs. So we may well no longer be the leading per capita. So we need to pick up our game. Getting the number one position.

Neil Martin | 6:27 

it's good to have some competition, and I think Australia love a competition and trying to be number one. So that might be a great incentive. Obviously, the way you say it there sounds like it might be slightly easier for Australia. But I guess then it makes challenges for other countries to do that, if they don't have the same amount of sun, if they don't have the same amount of space. How do you think that pans out for countries that have that big challenge?

Zi Ouyang | 6:51 

Well, you have to be green in some way. If it is not that you generate, like, for example, solar in your territory, then you have to use the solar to transfer the energy and use that. Secondly, then there's not necessarily the energy, solar energy, for example, where it is generated will be the place where it is going to be used. So it's actually that's why we want to say that the globalisation even for renewable energy is very critical. You can't just look into individual countries, you really have to look at globally.

Renate Egan | 7:30 

And it's important to note that there's a really good balance, typically between solar and wind, even Australia, we probably be looking at a close to 50-50% split between solar and wind. We are blessed with a lot of land that can take the solar but we also have great wind resources. And most of the countries around the world will have a balance of solar and wind. And interestingly, a lot of the offshore wind, we hear about that a lot. It's happening in and around Europe, offshore wind is really quite prevalent. And it's starting to happen in and around Asia, but they can also do floating solar, particularly around the equator, where the sea is quite flat and still.

Neil Martin | 8:09 

Going back to the numbers that you mentioned in terms of the growth, especially in Australia. How do you perceive that growth to be achieved? Is it just a case of putting more solar panels in more places? Or does that come from solar panels being more efficient? What kind of drives that growth?

Renate Egan | 8:30 

Both. So we've seen in the last 20 years, we've seen that average efficiency from the modules being produced double. So from 10-11-12%. Now module efficiencies are up at 24%. So you're getting twice as much power out at the same space. And the technology limit for silicon is going to we're going to see those module efficiencies go probably to 25%, maybe 26%. And then so the research that we're doing is looking at pushing that beyond 25-26% to more like 30%. So there's a research element that will see higher efficiencies, the price continues to drop, phenomenally.

Neil Martin | 9:09 

And what's driving that price drop?

Renate Egan | 9:11 

Economies of scale, largely, and increased automation.

Zi Ouyang | 9:15 

Yeah, there's just two factors. One is, is efficiency, not any more efficient solar panels, but the more efficient equipment use and the resources like keep reduction of the silver usage per cell or per watt. And also it's a scale of manufacturing. That makes things just cheaper.

Neil Martin | 9:35 

But you also said Renate, I think that there will be more solar panels in more places, which obviously the more you put up, the more power you get out.

Renate Egan | 9:43 

Yeah, that's right. So Australia leads the world in rooftop solar. And as a result, we have some of the cheapest rooftop installs, because we've been doing it for so long. And because we've streamlined all the processes. The cost of putting solar on the roof in the US is at least two to three times more expensive than in Australia. It's phenomenal, though, because of regulatory overheads and market dynamics, they've actually not been able to drive the price down nearly as much as we have here by doing, we've been learning by doing. What we have done, we've also done studies around the commercial industrial rooftops around how much solar we can put on commercial and industrial rooftops and their space for three times as much solar as we currently have installed on commercial industrial rooftops. If you ever look at Google Maps, or if you fly into a city, look at all those rooftops it's phenomenal real estate, and it's producing energy where it's needed, which is why we should be having more on commercial industrial rooftops.

Neil Martin | 10:40 

Ouyang, do you see the same kind of developments abroad? Maybe A, with regards to that kind of rooftop solar, but I've been looking in some research and say, for example, China seem to be doing a lot of big solar panel arrays in the desert, for example, how do you see global developments happening to kind of boost those numbers?

Zi Ouyang | 11:00 

Globally I think, if you can't remember the number, then it's 50-50. That's a good starting point. It's really about, we call it distributed system: where the usage is where the power is generated. And also we have centralised or ground-based big solar plants, where you need to use the transmission line to pump energy to big cities, or something like that. And if we look at market, you will find interesting, very interesting, we talk about 2030, 2050 target, right and you you put up the line is roughly 25% growth each year. On average, you find that number actually pretty, pretty accurate. But each year, it's always fluctuating. But if you dig it a bit further, you will find, take Australia, for example, when you have a big year for solar, and then the number will go small, because you find the grid cannot take that much more, then you will have good business in terms of a transmission line upgrade, and battery storage. So what I'm saying is, whenever you have a small year for solar, you have a big year for battery. And once the system, the grid can take more than you find the battery market is not that great anymore, and so it is picking up. So it's always balanced, you find it interesting, the market is always balanced in a phase that match very well.

Neil Martin | 12:25 

And it may be proves that all of these things are interlocked and dependent on each other. You mentioned batches there. And that's interesting, I think, because I guess the kind of basic criticism that sometimes gets thrown is oh, well, it's not always sunny. And what are we going to do if it's a cloudy day? I guess the battery technology does come into that in terms of the development and the storage that I guess needs to keep progressing as much as the solar panels and the efficiencies that you were talking about.

Renate Egan | 12:57 

Yeah, that's right, Neil. And it is, it's phenomenal. And it's actually assisted by the growth in electric vehicles. Because the huge market for electric vehicles is driving technology development in batteries, generally. We actually have all the technologies we need to deliver this energy transition. What we need is to develop them to drive the prices down, and to get the integration right. So making sure we've got the enough of everything installed when we need it as coal fire plants come offline, and to make sure that's integrated, and again, that the consumer understands. And we need to send messages to the consumer, about when the price of energy is lowest and when it's highest. You'll recall that we've had hot water system off-peak electricity for a long time, because energy demand overnight was low. So people were incentivized to heat their water overnight. [Neil: and some people get obsessed by that] Yes, while and so you I can tell you, you also get obsessed by your battery, when you've got one at home, your energy consumption and use, that's going to shift because it's the cost of energy in the middle of the day is going to be effectively zero. Because we are already seeing in the middle of summer, now, over capacity, we have more energy than we need in the middle of the day. So what we need to do is incentivize people to start to use that whether it's to charge your car, charge your house battery, or to heat the hot water. Industry are also driven by it too, because obviously the cost of energy is important to industrial processes. And they're seeing now, how cost effective solar and wind are and moving their processes. There are lots of big industries who are actually building their own solar plant on their own land behind the metre so that they can access this really low cost of energy,

Neil Martin | 14:43

Which potentially drives the cost down of lots of things. [Renate: Yes] Which will be benefit to everyone, especially in the current cost of living crisis. I'm sure people will be keen to hear that. You mentioned there about these being engineering challenges by believe there are technological developments that are happening in solar power technologies and developments. I wonder if you could just talk a little bit about some of those that might be new. People might not have heard of them at the moment, I guess they might have have knowledge of silicon-based solar panels. But maybe those won't be so common in the future. What are some of the new things that might be coming online? In the next sort of 10 to 20 years?

Renate Egan | 15:26 

Yeah, we're actually a really quite an exciting stage. So UNSW, you may be aware held the record for the silicon solar cell efficiencies for some 30 years, at around just over 25% efficient was the solar cells that we held that record until 2010, or thereabouts. And there are now manufacturers producing solar cells at that as an average efficiency, because manufacturing is happening at such a significant scale, millions and millions of solar cells are being produced every day. So they're actually able to refine the processes well beyond what you can do in a lab. So they're actually achieving average efficiencies at the level that we were--

Neil Martin | 16:10

Used to be the world record. [So absolutely, firstly] It's the equivalent of every normal person running 9.5 seconds, yeah, 100 metres like Usain Bolt.

Renate Egan | 16:19 

That's right. So just because we all got, you know, busy and tried to improve our fitness. So even the manufacturers are looking at the ceiling that they are facing with the technology and saying what's next, and the universities are driving the research into the what next of solar cells. So the way to think of it is that the solar cell is kind of like a single battery. And the way it works is it absorbs some of the sun's light. And miraculously, with just the material, the silicone material can turn that sunlight into electricity, there are gaps in that sunlight that silicon can't access. So we want to add another cell on top that will absorb the light that the silicon is missing. So we call that a tandem structure: two cells, one on top of the other. And we're working on the materials that there's innovation and discovery going on on the on the material, that would be ideal for that tandem structure, it has to take the rest of the light that silicon is missing, but not take too much of the light that silicon is really good at absorbing. So now we're looking at how to stack that on top of silicon. And we're also mindful because silicon is an amazing material, it's so stable. So we can put the silicon solar cells out in the field, the panels now have a lifetime guarantee of 30-plus years, that they'll sit out there in the field and produce as much as 90%. So the material that goes on top has to be as stable. So we're working on improving the stability of these materials as well and fitting the cells together to make the tandem. It's fun stuff.

Neil Martin | 17:50 

Ouyang, you must be excited about that kind of development as well. Do you see that being the big new thing for solar panels? Or is there something else that might be in development?

Zi Ouyang | 18:03 

Yes, now. Yeah, I agree with Renate, tandem will be the future. Almost 100%, maybe I should say 99.9%. But what's been put on top? That's still a question in my mind. So in my group, and we work on perovskite, like a company like JA solar, A tier-one company, we not necessarily we will produce all the solar panels in different ways at the gigawatt scale. But we definitely have in our R&D team tried everything you know, there. I asked my colleagues, please look into other materials because we still have problems to be solved for perovskite and not necessarily we will have the solution at the right time. I always emphasise at the right time, because we talking about 25% growth each year. And my company produce this year, I think, close to 100-gigawatt solar panels. If any technology, no matter its manufacturability or the market or stabilization issue, like Renate said, cannot fulfil such a large scale, then it's a big question mark for that.

Neil Martin | 19:19 

Yeah, and I guess there's always a gap between what's happening on the R&D or the in the academic sphere. And like you said, what actually needs to be done on a commercial scale? Are there some numbers of--I know sometimes people will have theories about how efficient certain things can be and they they know that they can get to that number? Is that the case with these tandem cells that you you think you can get to maybe 50%, or whatever number it might be?

Renate Egan | 19:47

So, we've already demonstrated efficiencies over 40% for a tandem cell technology, but it's not a manufacturable process. We've demonstrated efficiencies over 30 percent of a tandem cell technology which is closer to a manufacturing process. And we think we can both push that efficiency up and actually demonstrate it's manufacturable. So that's up from module efficiency or efficiencies of now 25%. So we're seeing the kind of that is the kind of boost that industry is interested in. So 30% is what were our targets are. And our targets are 30% by 2030. So we're really pushing to get a manufacturable sell process ready by 2030. And I'm sure that the industry is chasing that as well.

Zi Ouyang | 20:33 

Renate, I mean, I had a one, one, magic number to help you too. If you have to remember one number, that is for every 1%, absolute efficiency improve, you cut the cost down by roughly 6%. that magic number. It was there like 10 years ago, and still valid today. So that's the main drivers. So when we say high efficiency, low cost reliability, they all actually the triangle interlinked to each other.

Neil Martin | 21:05

When I was researching this episode, looking at future solar technologies, one thing that cropped up that I thought was quite interesting was people were talking about the potential for developing solar paint, which seemed to be a paint that you put on your wall and it has photovoltaic properties that would then you know, create power, is that going to be happening in the future, do you think?

Renate Egan | 21:30 

My perspective on the concept of solar paint is one that helps people understand that solar will be everywhere, right, so that we can cover all surfaces with solar, the idea that we can paint it on at home, and that will generate power is very future thinking, blue sky thinking, inspirational if you like. But the reality is we are actually producing now in Australia, at the CSIRO in Melbourne, and a group in the University of Newcastle, a thin film, roll to roll printing process a bit like the way our old bank notes are, current bank notes are still printed. And the way chip packets are printed. On a flexible polymer backing, you can print materials that you can turn into solar cells. So that's possible. And you can imagine hanging solar canopies, flexible solar arrays in various surfaces, the performance is a little larger than the ones that are fit for rooftop solar panels in the field solar panels. But the concept of solar paint, I think translates to these thin film sort of flexible panels, which can go on every surface. Ouyang?

Zi Ouyang | 22:41

Yeah, I agree.

It's not something that you go and paint the house, you need to have the professional to do it.

Neil Martin | 22:48

I guess the point you made those is quite important that these things do need to be efficient. And they do need to be giving you a decent output of power to make them worthwhile. And maybe they're not there yet. But you know, I guess development is going on a pace with those as well.

Renate Egan | 23:03

it's certainly being developed, driving down cost, there are efficiency limits to those technologies, that will mean that they probably will never--some of the organic photovoltaics, which is the OPVs organic, are pushing 20% now in the laboratories, but I still think that means that the flexible films are going to be probably 10 to 15% efficient.

Neil Martin | 23:28

One of the other things that came up was regarding solar windows, which I guess kind of makes sense. Because, you know, again, you talk about solar power everywhere, we have windows everywhere, so seems to make sense to me that you just make a window that also creates power,

Zi Ouyang | 23:48 

It is kind of contradicting because in order to make the solar cell more efficiently, it needs to absorb more light. But on the other hand, that window needs to be transparent, in order to see through. So it's kind of not the same way. But fortunately, what do we see through our eyes is not necessarily all the energy in a spectrum that can be used by the solar cell. So some smart engineering can play a role that makes sure some of the spectrum can be used for the solar cells to generate electricity without affecting the stuff you can see through the window. So yes, there's a definitely a potential for solar window, but we shouldn't expect it to be as efficient as the standard solar modules.

Renate Egan | 24:38

There are also some interesting designs being developed, where the solid absorbing materials are not in the glass of the window, but they're in the frame of the window. So it is still effectively a solar window. But it's not what you might conceive of straight away. It's the the frame or the structures of the frame that are used to generate the energy.

Neil Martin | 25:00 

This episode is called to engineering the future very futuristic thing I read Ouyang, I don't know if you're aware that apparently recently they put a receiver in space to pick up solar power from space and beam it back to Earth seems very futuristic to me do perceive that to be something that might be happening in 2050?

Zi Ouyang | 25:23 

Absolutely, there will be a niche market for that, but as a niche market. Yeah. So I'm like, in rural area, remote area where wiring is an issue. And you can't have a better way to get the power for an upgrade, or you don't even have a standalone system, then probably you can use that actually, I heard of this idea like five years ago, from Google, if I remember right, they funded one of the very futuristic ideas around their startup programme and why whatever I see, at this stage, the energy loss is an issue. And also the direction is an issue because you have imagine you have a satellite, you have to save the target where you want to transfer the energy on Earth, where you have to really zoom in and very focused almost like a laser technology to be very accurate. I see there's some very big engineering challenges. But now since you say 2050, why not? Anything can happen there.

Neil Martin | 26:22

Blue sky thinking or dark space thinking as it might be. Sounds like quite an expensive process, though,

Renate Egan | 26:29 

I put my cost effective lens onto this, and say that there will almost certainly be a more cost effective solution to delivery of energy, I cannot conceive of energy coming from outer space as being, you know, sending the solar panel payload up there, getting the engineering, right, I think it's all possible, I just don't think it's cost effective. And I think the problem they're trying to solve by putting solar in space is that the sun goes down problem, you know, the sun going down and coming up the next morning doesn't surprise us. We've been doing it for years. So we have been thinking about how to manage that. And there always is battery storage, obviously, there's pumped hydro storage, which is the greatest use of storage around the world today is pumped hydro, and very reliable. Once you get it built, then there's east west wiring or East West cabling, we're able to communicate through cabling, we'll be able to share energy through cabling.

Neil Martin | 27:24 

And I think this is already happening to a certain degree, I think, I think SunCable was a potential and, um, seems to have had some problems, shall we say, but maybe from an engineering perspective, it's not a problem. And also in China, I think they're building big solar panel arrays in the Gobi Desert and other deserts and transferring that to big cities.

Zi Ouyang | 27:50 

Yeah, they use ultra high voltage transmission line, you know, when you have very high voltage, then for the same power, the current is low, and therefore your energy loss in a green line is significantly reduced by orders. So you have to have the right infrastructure to make it happen when you have that yes is possible.

Renate Egan | 28:10 

And China is doing it. And that is the SunCable Vision. And the Suncable Vision was a SunShot Initiative if you'd like, you know, compare it to a Moonshot Initiative, to imagine a future where this is happening and to start to dream it. And I always thought it's still think with that project. Even if they get half the way there in twice the time, they will have achieved something that was not conceived of as possible. And that's worth doing. It's what we need to be doing is to be trying to achieve things that haven't been. And then again, it's engineering challenges, right? It's not that it's physically impossible. It's an engineering challenge.

Neil Martin | 28:51 

That seemed to run into some political or economic problems that I think are a bit too complicated for this episode.

Renate Egan | 28:57

It's a question of if we have all this opportunity around solar in Australia, do we export and we can see a decline in coal and gas market? How do we replace our economy with clean energy exports? And there are two ways to get that we're forecasting and one of them is through what we call a hydrogen economy, where we're producing hydrogen and its derivatives, notably ammonia, for export, which we can then ship around the world. Alternatively, we cable the energy out of Australia. So those are the two pathways. And basically, my understanding what happened is that the investors decided to lean on the hydrogen pathway, less than the cabling pathway, which is why they've hit a hurdle, but I do believe they're recovering and they're gonna continue with the cabling concept as well.

Neil Martin | 29:45 

Sounds good.

Zi Ouyang | 29:46 

And they all use solar anyway.

Renate Egan | 29:49 

At the heart of it, all of this clean energy revolution, and energy transition, our energy exports have the possibility that we can do further minerals processing in Australia. Because we all have this vast amount of green energy is on the back of having plenty of solar energy.

Zi Ouyang | 30:07 

Actually Neil when you ask the first question why Australia is ahead, my thinking, which is maybe debatable was that we have such a big mining industry, coal industry over there. So when you have to transform, you really have to find a way out. That's why push the renewable energy moving very fast. And it's somehow, you know, not so intuitive. But I think that big chunk of coal industry that actually play a role in our renewable energy development.

Neil Martin | 30:41 

You bring up the issue of mining there. And that's a good segue into something that I wanted to talk about with regards to the fact that there are scarce resources required for this growth in renewables and especially in solar panels. I guess there are also problems with that massive increase in growth that you were talking about Ouyang in terms of getting those scarce resources and the pressure that that might put on sustainability?

Zi Ouyang | 31:10

Well, actually, again, it's also cost effective. I mean, it's not only about Australia, globally, all the big energy companies, mining companies, they're all turning into renewable not only about the ESG issue, but it's also a revenue generator as well.

Renate Egan | 31:28

And I'm happy to talk to you about critical minerals and resources, because the silicon solar panels that we have today have the only element in there that the industry sees as a challenge is silver, right? Yeah, right, we currently use around 15 to 20% of the world's silver, and we need to double and then double again, the amount of solar we install so clearly, we can't do that with silver, because we're going to be using too much silver. But the industry responds to that. But we know that this is a challenge. So we're working on alternatives. There's an Australian company called Sundrive, who's looking at a silver-free processing. And there are other companies who are also looking for alternatives to silver to develop the technology without silver. So we will solve the silver problem. And that is the really in the silicon technologies today. The only element that is a challenge, silicon is just about the most abundant, comes from sand, plenty of sand out there. The other thing, of course, is that these things have long lifetimes, unlike a fossil fuel, which you dig it out of the ground, and you use it once and it's gone. These solar panels and batteries will have the batteries typically have a 10 year warranty lifetime, same story, 90% of that performance after 10 years, it's not the 10 years, you throw them away, it's that their performance is not you know, as it was the day they bought it. The same with silicon panels, 30 years there will be forming at 90% of the output power, the day they were bought. So these things have really long lifetimes and even at the end of their life, we can recycle them. So battery recycling is a really big industry because of the value of the elements in the battery. The elements in the solar panel other than silver don't have a lot of value. So there's not a lot of industry yet around solar panel recycling in a circular economy sense where you take the panel and put it back into this solar supply chain.

Zi Ouyang | 33:21 

Yeah, just give you another number. So when we say we meet the target, right, so then, with 25-30 years of lifetime, you probably still when the industry sort of stopped growing, you still have to replace I think three, maybe to five terawatts of solar panels each year. So that's probably the scale of recycling industry.

Renate Egan | 33:46 

At which point it will be cost effective.

Neil Martin | 33:49

But I guess we're maybe starting to see a bigger and bigger growth in that solar panel recycling because those may be right, the first generation that were kind of taken up by especially the Australian public and now coming to the end of that kind of I think 15 to 20 years. So is there a big spike at the moment of maybe solar panels that do need to be recycled?

Renate Egan | 34:11 

We've just done a study on that. We're looking at the panel's where they're deployed, where Australia has some really good data on the back of the incentives that the government put in place around installation of solar panels. As a result, we know where they all are. So we've been doing some analysis about when they come out off the field. But the volumes still are small, currently. And is there a spike? The spike will happen when the first large scale solar farms come offline? And then it's an industry challenge or an opportunity if you like, and they're aware of it.

Neil Martin | 34:47 

And I'm guessing this is happening across the globe. Ouyang. It's not just an Australian issue with regards to solar panels now being needed to be recycled properly, and in a kind of sustainable way.

Zi Ouyang | 35:00 

Yeah and one of the biggest issues is the logistics. So it's heavy, it's better to be treated locally on site, which is interesting um, we see some alignment between the kind of waste management companies, they are mostly interested in this one, because they also have the distribution of resources around the world. And if you have to ship your solar panels, for example, at the end of the life ship back all the way back to China, for example, to my company, then that's not the way how it will work. Now, how it works is, I think the law is going to be in placed is that when you sell a solar panel you put, correct me if I'm wrong Renate, is you add a little bit of the fee to the price of the solar panel at the end, then that money is going to be funded for the management of the waste.

Renate Egan | 35:56 

Australia is developing regulations around that. And that is one of the plans that is definitely happening in Europe. And it has been happening with--so there's one US based company and making with a strong reputation in solar and they add it they they add it to their price at the solar, the cost of recycling, in the industry of being a green energy industry is mindful of its lifetime issues.

Neil Martin | 36:23 

I was gonna say is that a thing that is front and centre? Because you don't want to be accused of not being environmentally friendly at any point of the supply chain?

Renate Egan | 36:34 

No, we're held to a much higher bar than any other industry.

Neil Martin | 36:38 

Does it frustrate you sometimes that people will pick on slight little things of Oh, will it cost that much to transport or--

Zi Ouyang | 36:46

Actually not at all, because everything is calculated, very sophisticated, we call it part of the ESG, I guess. Actually a lot of--in my company, some big projects, when they set up the sort of criteria for selection of panels, they have very, very strong incentives in terms of green manufacturing and green production, we have to tick all the boxes. So I don't think it's unusual. And actually, we tried all our ways to make it greener and greener.

Neil Martin | 37:17 

My point was more that critics will always jump on something. And does that frustrate you that every slight little thing is criticised.

Renate Egan | 37:26 

So it doesn't, I'm perfectly happy to be held to account. So there's a whole lot of innovation, chemistry and material science going on around taking the panels apart. But also looking at how when we build them in the first place. If we can build them both to last 40 years, but to be easy to take apart when we're ready to take them apart. So there's we're absolutely owning the challenge, and no problem being held to account because we want to be able to justify this pathway.

Zi Ouyang | 37:54 

No problems at all. I'm very happy to take that challenge. Actually, we are taking the challenge throughout the way. For example, when we have to make a choice between stainless steel frame and aluminium frame. And we have to think about the carbon emission and the weight. That's one box to tick, we have to choose one material or the other. We have to choose HJT or Topcon. One is a low temperature process one is a high temperature process, then we have to think well, if it is possible, we would like to use low temperature process. So when we view the solar panels, we check the boom of a material with the process, the temperature, the emission, and the floor, I base the back sheet, for example, we have to think about it very carefully, because that could be a toxic material. So when we build it, we think it very thorough.

Neil Martin | 38:50

All of these things sound very exciting. And my impression is that the young generation have this front and centre in their mind more and more. Just to finish off. I wondered if I could ask you, if you were a 16 or 17 year old today thinking of going into a career related to solar energy? What would you be most excited about?

Renate Egan | 39:11 

The opportunity to change the world to really have to do something where you really make a difference to use your powers for good. And to be sure that there's a job in it. They're not all engineering jobs. We need the lawyers, we need the bankers, we need the communicators, all on--and the teachers all on side.

Neil Martin | 39:32 

Ouyang, what would you be most excited about? If you could be that 16 or 17 year old,

Zi Ouyang | 39:39 

Almost the same as Renate but probably placed in a different way. Like if I have to make a choice, like for example graduate from high school and much major to take, I would think in a pool I have the things I want to do. And I have to forecast the future of the career. And then we have the significance and meaningfulness of the job then if you combine together, renewable and solar, that's the way to go.

Neil Martin | 40:05

This has been a really illuminating discussion, I think for everyone, Professor Renate Egan, many thanks for making the time to join us [a great pleasure]. And thanks also to Dr. Ouyang. It's been great to speak with you this [The same to you]. Unfortunately, that's all we've got time for today. Thank you for listening. I've been Neil Martin, and I hope you'll join me again soon for the next episode in our engineering the future series.

Voiceover | 40:35

You've been listening to the UNSW Engineering the Future podcast. Don't forget to subscribe to our series to stay updated on upcoming episodes. Check out our show notes for details on in-person events, panel discussions and more fascinating insights into the future of engineering.