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Episode #001 - Jens Schneider

Updated: Mar 9, 2022

Episode #001 with Torsten Brammer & Jens Schneider:

Having graduated with a Ph.D. from Helmholtz Zentrum in Berlin in 2005, Jens Schneider embarked on a career that took him from being an engineer at CSG solar to heading up the Solar Module Technology group at the prestigious Fraunhofer CSP in Halle, Germany.

Jens currently juggles a couple of different positions in the solar space, being a professor at Leipzig’s University of Applied Sciences and working with the Center for Economics of Materials (CEM) in Energy System Analysis.  

We are pleased to have the professor on as our first guest on The Solar Journey podcast, bringing us back to school for this online masterclass.  

So prof, show us the way to a 100% renewable energy future…. 

Show Notes:

Interesting points covered in this episode for those of us on our own Solar Journey):

  • How does one survive an intercontinental flight when seated with our host Torsten?

  • Where did the Solar Journey begin for Jens?

  • How do students drive movements and nudge others along in doing their bit? - How do you balance the fine line between science and politics? 

  • How will Covid-19 affect the movements towards a sustainable future? 

  • How cheap is solar really? 

  • What is a Power Purchase Agreement (PPA)?

  • Can solar stand on its own, or does the state need to assist this industry still?

  • How do you understand the balance between electricity and heating requirements?

  • Understanding how energy systems have to transition their business models from being OPEX to CAPEX based. 

  • How much PV would be needed in Germany for it to be powered by a hundred percent renewables?

  • How many people are working in the renewable energy sector globally?


[0:00] Host: All right. Welcome to my new podcast. It's called The Solar Journey. And for the show, I will invite people who are working in the solar industry, in the wind industry or the energy industry in general. And I'm interested to find out what is their motivation? What is the motivation of these people, why they work in that industry? And what kind of challenges are there and what they think where the energy industry should move to, should be headed. And today on my very first show, I’ll have as my guest an old friend. It's Jens Schneider. He's a professor here at the University in Leipzig. And he conducts research at the Center for Material Economics. It's called CEM. And this is part of a front for institute in Leipzig, Germany.

[00:01:00] Host: And he's been doing this since the early 2020 and he works on energy system development. So precisely who conducts research on how to manage the structural change in the coal regions, national and international. So the transformation of the energy system towards a sustainable approach. Previously from 2014 to 2019. Jens was a foundation professor and from 2019, he's an honorary professor at the H.T. W.K. That's a university here in Leipzig of Applied Science. And before that, between 2011 and 2018, he was a group leader for solar module technology at another foreign institute in Halla, also in Germany.

[00:02:00] Host: And from 2005 until 2011, he worked as a plant and process engineer at CSG Solar. A company founded by Professor Martin Green from the Eunice W in Australia and Shi Sola itself was then a subsidiary of Q Cells, which is now operating under the name Hanwha Q cells, one of the top 10 solar cell manufacturers worldwide. Jens Schneider did his a doctorate in the field of silicon thin film photovoltaics. And so Jens started as a researcher, PV specialist, and he was part of the big PV boom here in Germany, and then he moved into the field of economics and the structural changes in the energy sector. So, Jens, welcome to the show. Thanks for volunteering as my very first guest.

[00:03:00] Guest: Hi, (Johnson), nice to see you again.

Host: Yeah. So these are special circumstances. We were planning to meet face to face and have a walk through Leipzig. Have a chat about the solar energy. And now with a COVID 19. It is now the thirty first of March 2020. We are limited to our homes. So this is why we run the show now via Zoom. I think they must be making a nice jump in subscribers. Everybody's switching to video conferencing. So how does your work day look like? I meet you now at your office. At home, I guess.

Guest: Yes. This is my home office. Welcome to my home office. Yeah. Our whole family's home. My wife and the kids. And sometimes you can hear them in the back. I think I told them to be quiet. But I think it's hard to have the family quiet all the time.

[00:04:00] Guest: So we have to cope with these circumstances. But I must say that it actually works out quite all right. I get to get things done. I'm a bit surprised by that. But the kids are behaved nicely and maybe also surprised by that fact.

Host: Yeah, it's crazy. Besides doing podcasts, I mean, I'm the CEO of a metrology company in Germany, and all business now runs via video conferencing. It's pretty crazy how swiftly our day to day life has changed. And I was always at home with two kids. I'm actually now in our bedroom. And let's see how my kids behave today. Yeah. I actually I would like to add that Jens and I we met many, many years ago. I did some research last night. It must have been in 2003 on our way to Osaka, Japan.

[00:05:00]Host: To one of the PV photovoltaics world conferences, and we spent most of the flight back then in the back of the plane. Drinking lots of red wine.

Guest: No, that wasn't fun anymore. I didn't know was there any either way.

Host: I mean, it was pretty insane, right? I mean, we were civil servants back then. PhD student myself. And so. Free booze was pretty cool anyhow. Then we had to sit down and maybe that was to the good of us. Yes. You were born in (intelligible), now you're in Leipzig. You work in the solar industry. How did how did that all happen? Why? Why did you go that direction?

Guest: Actually, there was one point in time where I decided to go into this field and this was still back in school times.

[00:06:00] Guest: I read a Geo article, which is the German National Geographic's about a Maurey and Hunter Levins from Rocky Mountain Institute in Colorado, in the U.S.. Yeah. And they worked on the energy sustainability field. And they still do this today. It's quite amazing. And this was very inspiring to me. I thought, well, that's very interesting. That's something I can envision for myself as well. Because it fitted all the requirements I had that I was thinking about what a job should do for me is to be interesting and fun and should be ethically something that I can support. It was clear that I was more of a technical person, so it was a technical topic and something where I thought this would have a big future. So I decided to go this way. And from the general energy topic, it moved towards photovoltaics fairly soon.

[00:07:02] Guest: And so this journey took me by our starting electrical engineering and Duisberg, where I was told that our photovoltaics were not teaching this. The energy density is too low. This will never have any important role by a billion. And HMI, my PhD in Silicon thin film Photovoltaics there are two q cells heads or CSG solar and then Leipzig got found over.

Host: Pretty cool, pretty cool. So, what are you working on now as a professor at the Fraunhofer Institute?

Guest: So the lecture I still do at university deals with how to transform the energy system.

Host: Yeah.

Guest: To keep our climate goals. So we have a model for Germany, for electricity, for eating, for mobility and for industrial processes and all the energy required.

[00:08:05] Guest: It's a fairly simple model. We have a reference model for Germany for 2015 and the students have the opportunity. So it's a energy engineering students and their master program. And they have the opportunity to simulate for themselves how they can achieve climate goals for 2030 and 2050. And it's a huge task for them. And I think it's really important for them to get the big pictures and to understand the quantities that we have to cope with. And I enjoy teaching this course, and I hope that some of the students enjoy it, too.

Guest: All right. What do you like about teaching? So from a lab engineer to a teacher. What was what fascinates you about teaching?

Guest: I’ve always been teaching even in school times. I've been assisting younger students with their homework and with their math courses and so forth.

[00:09:02] Guest: And also at university, I earn some money on the side with teaching. And I once spoke to another friend about what motivates us in our work and for me, it was always the big picture doing the energy transformation system. But I was told from the friend that he's mostly motivated if he can improve people, if people come to him and seek advice. People working for him and he can give them that advice and he can feel that they are they've learned something and they have improved themselves. That's really, really satisfying for him. And I must say that I can share this feeling. And I think it's a great opportunity to share what you've learned and discuss with people. And I especially like the approach where students can try to find out themselves what's good for them.

[00:10:00] Guest: And I don't really tell them this is the way to go. But we can discuss these things and see how to move forward and quantify our results. So that's really nice and interesting. And I like young people. I have to say that maybe we get to this later. I can with now the ideas for future movement. I really think young people today are very motivated, highly motivated, and what they're doing also in designing their future and caring about the future. And they have one big advantage as opposed to us. When you work 20 or 30 years in one field, whatever your viewpoint, you get a bit stuck in some opinions and you can be odd and I have the feeling that people don't have this as much. So they're open for new points and they can adapt much quicker and understand different positions.

[00:11:00] Guest: So I really like working with young people. Like teaching.

Host: Do you get real feedback from your students? Oh, is it is it a one directional thing? Do they tell you. Hey, this was really a cool cause or how do you, I mean, you give a lot of energy. Do you get energy back from the students somehow?

Guest: Definitely. Observation was the last hour to discuss how the course went, to get some feedback and give some feedback and ask for what they liked and what they didn't like and what I can improve the next time. And I think that's always really interesting and I do get the feeling that a lot of good things and as always, room for improvement. So. that gives me a lot of energy.

Host: Yeah. Cool. Yeah. You just mentioned the phrase for future. So we're also young Leipzig. And, of course, worldwide. This was a while. It still is. I mean, now it kind of slowed down a little because we're not allowed to go outside.

[00:12:05] Host: But, uh, you’re also pretty active in that in that in that group right.

Guest: I'm not too active, but I try to be there as often as I can. And every once in a while and when I'm asked to support something like to explain a bit about a bigger picture on the energy system or on research point of view for different topics. I tried to help as much as I can, but it's… wherever you go, it's always clear that it's the students who drive this. It's not parents or scientists or people like us who are supposed to drive. This is a student movement, and I think it's good this way.

Host: Okay. But you still have to. The parents of future scientists for futures, entrepreneurs for future. How do they interact with the original movement? The fighters for future kids and students.

[00:13:07] Guest: For example, Scientists for Future. They meet once a month in person at the university in Leipzig. I haven't been there for quite some time, I must admit, but I've been down a few times. And there you always have some. Representatives of Friday for future as well. And you have all the social media where you do have interaction. And the same is true for parents for future.

Host: Okay. And, uh, the way I understand it, uh, the students welcome these extra. Groups, parents of future centers for Future. All how do they look? We got them this extra route.

Guest: I think they always like this stay. Of course fought for the cause. It's the best to have as many people in society as possible. So this is why they like all the other movements and they specifically support scientists for future.

[00:14:02] Guest: Also the other way around in they because they that's the main claim that politics should listen to the scientists. And so, of course, scientists have a special meaning as far as I understand. And but I think it's important that all groups actually of different parts of society support this, support designing or finding a good future for all of us and supporting this. And I think the only moments where they probably don't like it too much is if we put forward two strong opinions ourselves. One has to be really careful about what you say because people are being watched very carefully. So I think that there has to be some discussion to see what makes sense. And I think Fighters for Futures also doing this quite an excellent manner as far as I understand. They have weekly forum conferences like this one just with one hundred people and a hundred parties that that's really crazy.

[00:15:04] Guest: So they've developed a different skills, how to actually agree to something? I think what they do is they do this to show that they support. So this is clapping without any noise and other hand signs and so forth. Because if a hundred people clap, I think it gets really loud. So I think they're really clever. They learn a lot. They learn a lot of organizational skills. I think they learn a lot of skills that they will be able to use in their later professional life as well. So I think it's a really great movement.

Host: Now, with COVID-19, that has a lot of. Questions come up. Where's Clayton now? Where's Fridays for future now? So. So they keep working in the virtual room, as I understand.

Guest: Yes. So I think there was a very nice post of Cater Hamburg where she said that young people were also support the old people in regard that they stay at home and don't call for demonstration on strike, but rather move to online approaches.

[00:16:15] Guest: And they have webinars now with highly qualified people and are in discussions. So I think they're really, really creative. And it can be very much appreciated.

Host: So it sounds like the movement doesn't, uh, doesn't suffer from the COVID-19. Let’s say a break. You think they’re gonna come back as strong as they were before?

Guest: I hope so. I think they have suffered before because they have seen that they have been out on the streets for a year and they do have the feeling that they did not achieve what they seek to achieve. To have a plan on how to adapt further to achieving our climate goals, how to adapt to the Paris agreement.

[00:17:02] Guest: But one must say that they have achieved a lot. I think the discussion on climate change has been huge in the last year, and I think it still is. And I think the task is not over, so it's important to stay focused and stay with it and keep taking the people out to the streets and raising the attention of everyone to discuss this further. But, of course, first we have to get through the COVID-19 crisis, and this is not over. And I think only once this is over, we can really judge what challenges are ahead of us. So we know that the climate change challenge will not go away. But we must see how much we can.

[00:18:00] Guest: Focus on climate change again and how much that discussion will go away from it into pure economic topics, for example. And I think that might be also personnel issues. I mean, people dying is not exactly a nice thing to happen.

Host: Yeah. So that's another interesting aspect, right? I mean besides the social personal tragedies we are facing now that the impact on the economy will be pretty high, right? So, what's your guess? How would… How would the politics in Germany or worldwide different regions handle the situation once we are back, let's say, to hopefully normal conditions? Is the energy transformation then totally off the table because it’s called to be too expensive?

[00:19:00] Host: Focus on other on other subjects, or do you think we can switch back to where we were before?

Guest: So, I don't know. Yeah, I'm sure. We don't know how this will all turn out. So let's hope it's not gonna be as bad as the worst scenarios might indicate. But, yeah, this is something we nobody can predict so far. Let's keep our fingers crossed. And but one thing that's sure that whatever it looks like afterwards, it's not like you can make any case that you should not do the energy transformation anymore. And it's just simply not right to claim that it's expensive, it's not. For example, our solar industry is the least costly way to provide electricity today, even in regions like Germany is life. We must definitely move this further.

[00:20:01] Guest: And I think it's a huge opportunity for a lot of countries to get access to low cost electricity and to even engage harder in this transformation than before. But who knows what forces will try to make what case? But from my point of view, it's clear we must stay with it. You must stay with the energy transformation.

Host: Okay. You just mentioned that the P.V. photovoltaics, the electricity from the sun is now one of the cheapest energy source. Can you can you get some some figures? Do you have some comparison at hand?

Guest: So in Germany, I think a good way to look at it is the tenders for large utility PV systems because they are fully transparent and there you achieve numbers even below four cents per kilowatt hour.

[00:21:00] Guest: And that is for systems which are limited in size to 10 megawatts. And we have seen the first systems in Europe and also in Germany, I think it has now started to build there 150, 170 megawatt solar power Blandon handbook. And I think the costs there are gonna be even lower. So this is not really extraordinarily low. And if you look at coal industry, I think they have to pay almost this money for CO2 certificates without even paying for coal. So I think that it's way more costly than photovoltaics, electricity.

Host: Okay. All right. You just mentioned that the 10 megawatt limit. Why is there a limit? What sort of limit is that?

[00:22:03] Guest: I really don't know. It's I think completely erratic. And there's no good reason for this. No and no other electricity generation, there is such a limit. So. But I think it's not maybe too important. It's just a pain. But it's. It's not stopping us because we have to move to systems. Where we do not need any funding for these type of utilities like we are seeing now with a large system where you can actually directly sell that electricity as well in the market or by our power purchase agreements. I think there's a huge opportunity out there. I think we must rather support these type of business models with power purchase agreements made with loan guarantees until the banks actually believe that's a good idea.

[00:23:04] Guest: And do proper financing and then I think this is the way to go. But it's really …that 10 megawatt limit is completely crazy.

Host: Totally crazy, huh? So you just mentioned the power purchase agreement. How does that work? I guess that's a deal between the owner of the solar park and a customer.

Guest: Yes.

Host: How is it awarded?

Guest: From my understanding. Basically, companies who use electricity are afraid of the cost of electricity rising. And companies will try to sell electricity for whatever reason or for whatever source, but also from photovoltaics or wind energy. They are afraid of electricity, these costs dropping. This would mean that they cannot get their loans paid.

[00:24:00] Guest: And it's basically some sort of an insurance. So both parties agree. Well, let's have a fixed price. And if the price is higher, then we still meet at this intermediate prize of its low while we do the same. All we reimburse each other. If it's high or low or so, we have a guaranteed price. And both of us can calculate this number for the next 10 or 15 years. And this helps both sides. And I think that's a really good way forward.

Host: Okay. No PV plans of course, a fluctuating source of energy. Right. So how is that taken into account in this case? What do you say, like he was out at 12:00 and 12:00 lunchtime or. Or is it, uh, kilowatt hours or can cover the whole place? Or how does it work?

[00:25:02] Guest: There's different opportunities how to do this, but I guess it sells against the day ahead market price. And of course, it can't. You can only sell the electricity if you've got the electricity to sell. So it will be a reference to the day ahead stock market price for electricity. Okay, so you must have somebody who's actually trading there. So this could be large companies or it can be an intermediate company who uses this as part of their portfolio for selling electricity. And, of course, with a large utility company like EM B.W., they can actually use that as part of their portfolio.

Host: So what is required that PVAs or any other. It's a non-government supported scheme is necessary for solar energy. What we need? What are the steps? That need to be taken. In Germany or any other country.

[00:26:00] Guest: As far as I understand, in other countries, this is far more developed. And this has to do with the German feed in tariff because we do have a feed in tariff already. It was not so necessary to develop PVAs in these other countries without feed in tariffs or know reasonable feed in tariffs developed this earlier, and I think they are further developed, but as far as I understand, really, they're very close to getting this. I think it's mostly almost like a marketing issues that you get this. Companies must know that there is this opportunity and then they must use it. And maybe the only thing left there is you need to have financing from banks. And banks don't know this business yet. And they must get confidence to take it, their credit repaid.

[00:27:00] Guest: And I think in order to get this confidence, it would be good, for example, for the German coffee bank. OK. Stayed on bank to give such loan guarantees to support other banks to trust this type of business.

Host: OK.

Guest: And I think this is something which you only need to do for a fairly limited period in time. And once banks are used to the business and have achieved this trust, then you can let go and let it be in the free market.

Host: Ok. Excellent. Did you know countries where PVAs are already widely used?

Guest: As far as I understand, some of the Scandinavian countries do this. There is… I visited a power plant in Spain in which a solar power plant, a utility which uses such PBS.

[00:28:00] Guest: I think that in southern Europe, obviously, the costs are even lower. So there you have a market coming up, I think Portugal, Spain and Italy. Are markets which are being closely watched from companies, from system installers to see what type of PPA is a possible.

Host: Ok. Interesting. So, uh. I mean, here in Saxony, Leipzig. We are in, let’s see, he has a lot of brown coal mining. As I stand on my terrace balcony and look towards the South. I can see a massive Brown, coal power plant creating nice clouds in the sky. So you can clearly see that this region massively depends on that kind of industry or at least this is what it's usually being told.

[29:00] Host: So along with, let's say trust of banks in this kind of energy is also a lot more needs to be done. I would assume too, to switch, our energy supply system towards a renewable one. And I think this is one of your focus topics as a professor, right? So maybe you can shed some light off what else needs to be done to get to say, let's say 25% renewables coverage across all energy demand or maybe 50 and then maybe 75%. So what, what would be the steps that need to be taken as a honor from the industry from policy? From all stakeholders?

Guest: So I think definitely all sectors must contribute to the energy system. Transformation can not only be done by electricity, but at least electricity has to extend in other marketplaces.

[30:04] Guest: And we have to do the transition in all markets. What you see with the power plant South of Leipzig… It does two things. So one, it provides electricity and I think that's fairly straightforward to change. So you need more renewable electricity instead. Hmm. What's the different challenge is it provides heating for Leipzig with district heating that's of course, something where we do have to make a transition like Leipzig has decided to not use this source anymore after 2023, I think. And we will try and, and hopefully make build a gas a combined heating power blank. To provide the heating and then add more and more, for example, renewable sources or waste energy sources to such a system.

[31:02] Host: To cover their heat demand. But the heating demand that's for heating. Okay.

Guest: Yes, that’s for district heating. I know that a nice example is in Hamburg, there have been two decisions by the citizens of Hamburg to actually re buy their own power distribution company in the city and to move to renewable or CO2 free energy by 2030. And they also have district heating, which is a technically effective and financially effective way of actually providing heat. It's district heating. I think people agreed to this quite widely, but you have to do the transition. If you don't have a system yet for district heating, you must, you have a large hurdle to overcome large initial investment to overcome this, that you must overcome.

[32:02] Guest: But they have a lot of heavy industry in Hamburg for steel and for aluminum, and they use the waste process energy from this and put it into the district heating. So there's different opportunities how to do this. But in general, I would say there's many, many opportunities and you can be really creative and they can be a lot of innovation in this, but there's some things which are certain. It is absolutely certain that we need more solar energy. We need more wind energy. It is clear that we will shift to electromobility. It's not clear whether it's going to be battery powered or fuel cell powered with hydrogen. That's maybe still an open race, but I'm almost certain it will be electric cars.

Host: The battery or fuel cell. Alright.

[33:00] Guest: Yeah. I tend to more to battery, but I think that's an open race, but it will be electric powered. I don't think that it will be combustion engines in the future anymore. At least not in the small cars. And I think in heating, it will be clear that there are technologies like heat pumps will get more important. I think that thermal storage is something which has huge importance to shift energy around. So you can use when you have excess energy, you can produce heat. And when you have limited electricity, you don't need to provide heat, but you have this in your thermal storage, I think that’s unity and district heating wherever you can do it. So there's certain technologies, but almost everybody says that this plays an important role. So I think you must push those. And then I think it's fine to have an open market which sees competition, for example, between different storage opportunities, which gives the opportunity, whether you're expand your grid or you build local storage.

[34:06] Guest: I think there's very many different approaches to it. I think you must allow for innovation there. You must allow for information to be used, digitalization to help demand response or moving demand side management might be really interesting. And for example, like we see now, there is this big challenge, which is a real challenge that at least in Germany, we have times where we don't have wind or solar. And almost every year we have like about a week with very little wind or solar energy. The question is where to get the energy from, and people claim that you need a whole all the power plants still for this one week, but maybe it's also an opportunity to pay people to stay at home in this week and companies to close down.

[35:01] Guest: And now we see that, well, having one week, a year to stay at home, seems like child's play now. I am home two or three weeks, two and a half weeks now. I think it's not entirely impossible to do something like this. I think there's different opportunities. So there is things which are clear and there's other things where we still have room to play, but we must push in all directions and see what's the best solution.

Host: Yeah. Okay. I mean, let us briefly come back to the district heating. I don't know if that actually exists in other countries than Germany. So basically you have a long, long, long, long, long pipes going over kilometers from the power plant towards individual households, right?

Guest: Yep.

Host: If you use a gas, power plant, that's still not renewal. Right. So this would only be for a transition phase. So how would that look like in the, let's say the term longterm future?

[36:00] Host: How would you do, but that also go to solar or wind electricity heating. Do you use, do you think the future of heating is also electricity?

Guest: So I think a gas power plant, for example, the one we were hopefully built here in Leipzig will have the capabilities to switch into hydrogen fired or synthetic fuel as well. Or you have bio gas, which you can use, so, okay. Is renewable sources which can transition or you can add more and more parts of this. So I think that's an opportunity, but there is also, I think, other ways to do this, I think with electricity, I think direct electric heating, isn't a possibility, but also using heat pumps is always a possibility. I think that it might be a good idea to lower the temperature and district heating.

[37:00] Guest: So now we have, I think in Leipzig we get from the coal power plant, the water comes in at 130 degrees and it reaches live to get 110 degrees. And I think you could lower such a temperature and with the lower temperature, you can use solar thermal energy. For example, I think that starts goes up to 90 degrees or so. In a reasonable manner. And but you could also go much lower temperature. I've seen models with a cold combined district heating where you go down for example to 30 degrees but use three pumps and use that 30 degree water to pump the heat up to whatever temperature you need. And lower the temperature down to, for example, 10 degrees. And then you have the opportunity to, for example, use that type of water for cooling.

[38:00] Guest: Yeah computer centers are where you have your large server farms or so for IT cooling or other cooling requirements where you are at much lower temperature. And use that as an energy source and feed it directly into your district heating. So I think that's a great opportunity. But that's something which is not decided yet. I think that some of the more fancy technologies which are possible.

Host: Yeah. So I just read recently for 2019, around 14 to 15% of the total energy demand. So that includes mobility and heating was covered by are renewables, like 40 to 50%. Right. Is it correct?

Guest: I'm not quite sure, but sounds right.

[39:00] Host: Yeah. So, so what, what do you think in a realistic scenario, when we, when can we get to 25%, 50 or 75% and then… is there scenarios by the policy makers or by the political parties. What are the scenarios they fight for?

Guest: But scientists, or I think Germany's zero for example, is they have scenarios how to do this quicker. I liked the scenario from Alcoa and I give into the big picture which showed how we can transition 2030 to I think the call there 65% renewable. So I think it's huge efforts we have to make by lowering our electricity consumption. For example, in the building sector our energy consumption, and I'm moving away from combustion cars, like we have them today.

[40:00] Guest: And increasing the amount of electricity from the renewables. So I think we, in order to keep our Paris climate goals and in order to keep the global temperature below 1.5 degrees Celsius, we must reach zero, two emission by about 2035.

Host: Zero by 2035?

Guest: Yeah. So we must have huge parts of renewable electricity or renewable energy in Germany. I think that's a really, really huge challenge, but at least we have to take on this challenge. So we have to increase the amount of, for the world tags and wind energy. We set up very strongly. And I think now both have difficulties. I think solar, as both of us have seen, has already had quite large challenges in Germany. And I think wind is facing this now, or I started facing it last year and I think that's the wrong way to go.

[41:04] Host: Yeah.

Guest: This way it's it will be impossible to reach our goals.

Host: Yeah. And what about the financial demand? Is that, can that be a financed by the private industry? And would they invest into these energy sources because it's a, it gives them a high return on invest or does it have to be like a state dept finance?

Guest: Yeah. So I think that's a big, big challenge for the energy transformation that you have. You move away from a OPEX based energy system where a large portion of your cost is actually in the fuel you burn or use or whatever way to a system where most of your costs is actually in the investment, the capex.

[42:00] Guest: So you must invest into your system quite a lot of money, and then you have low rates to pay afterwards. So that is a challenge. Fortunately, at least it was the case that the interest rates were low. So that really helped the case and also the cost for capital intensive industries. So I think we should use that opportunity. It's hard for me to judge whether companies can do that themselves or whether the state must support this. I would hope that companies can do it like what we said earlier with the power purchase agreements. And I think it should be possible that the government should design the market in a way that you can make good profits from it. I think that's, it is a problem that with the rates you look at with solar for example, you still have fairly long times until you get a return of your invest.

[43:08] Guest: So it's, I think it's still around 10 years depending on what type of system you look at, but I think that's quite long for your investment to payback and that's probably a challenge.

Host: Yeah. Okay. And so recently in Germany, it's all dominated by it by legal boundary conditions. Right. So if I understand correctly, there's a cap on the PV, which is allowed to be installed in Germany, which has, I think 52 gigawatts.

Guest: Yes.

Host: That's one thing.

[44:00] Host: And the other one is now with the only reasonably, I don't know if the bill passed was passed that wind parks or windmills have to have a distance of at least one kilometer, which apparently reduces the potential for additional wind in Germany to close to zero. So is that correct? Is that correct? Recollection?

Guest: I understand that the same way. So I think that the 52 gigawatt cap for PV will go, nobody's supporting this anymore. It's just they want to have this as part of the deal. So they will only negotiate once the wind topic is clear and I think for the wind topic, it's actually, so with the two government parties in Germany one wants there's 1000 meter distance, minimum distance, and the other one wants to actually get, to give money to the communities, if they have a system close to their community. And I think the beauty is there's actually room for compromise.

[45:02] Guest: So you can have for example, you could say that, okay, you can only install systems further than 1000 meters away from the community. And if it's inside the system, then the community must be reimbursed. And then both would work out fine. And I think that then communities can say, okay, if I get this and that much money, I will, I think it's okay if we use this field over there and put some wind farms there and you could even do a competition, like a tender for how much money the communities would need and the ones which would be willing to accept it for the lowest contribution would have a competition. And which a lot of politicians like and you actually likes. And this way you would even find the lowest cost for putting up wind farms. So I think there's room for a compromise. I think that's always good.

[46:00] Guest: But something needs to be done. I think the way they plan to do it now with just a thousand meters from any house that's just ridiculous in Germany.

Host: Yeah. And I think the motivation was, I guess disturbance by in German it's challenge lock it's like the…

Guest: Okay. Infrasonic, whatever.

Host: Infrasonic noise.

Guest: Yeah. I think we must respect this. Whatever the people say, but I think if you would only, if communities can say themselves, yes, we do want it. If we do get our share of the money which is earned there and they do this, they agreed to it themselves first and they have to decide as a community whether they want it or not. I think that would take that would increase the acceptance quite a lot.

[47:05] Host: Yeah. Okay. And the 52 gigawatt cap, is there a, I guess there's no scientific background for that reason for that?

Guest: I think it absolutely. It's there is days in summer in the weekend. Where your maximum noon load is 52 gigawatts.

Host: Alright.

Guest: So that would mean in a sunny day. Mmm. 52 gigawatts of solar could provide 100% of electricity and the idea behind it might be a coincidence, but I think that people might have looked at this to say that you do not overproduce just from solar.

Host: Okay.

[48:00] Guest: But it's yeah, we need much higher numbers. All the tags in Germany. And if, anybody looks around, there are still so many empty roofs it's really amazing. You must get affordable tags and all these rules.

Host: Yeah. So we now have almost 52 gigawatts in Germany. What does a cost optimized system look like in Germany, how much PV would we have?

Guests: Hmm. I think there's actually multiple answers. So that's also what I learned, for example, from colleagues from foreign over Iza who do this in a very nice numerical simulation optimization with solvers to find out, which is the optimum system. And they find that there is different optimal. It's very, very close overall cost, but very different systems. Okay. Yeah. So.

[49:02] Guest: Yeah, the cost can be really just, yeah portions of cents. Apart from one other per kilowatt hour, but well, fractions of cents, but the system is entirely different. So you might have, for example, what I remember, they asked system switch, do we use solar, thermal energy and some which don't at all.

Host: Yeah.

Guest: And the cost difference is not too large. So, and I think with the uncertainty in how the prices developed, I think there's still room to find out what's the optimum solution, but for sure it will have a lot of photovoltaics and a lot of wind energy.

Host: Okay. So do you remember one of the, a figure like now it's 52 gigawatts, what's one of those scenarios, how much PV would that be in Germany for a hundred percent renewables, a hundred or 150 or 500?

[50:00] Guest: So definitely above 150. It really depends on what you try to achieve? So if you for example, if in our lecture, if we do these simulations and we do the energy transformation and you can see that the overall primary energy needed is always being reduced because a lot of the technologies are more efficient. Like electromobility is much more efficient than combustion engines. So while heat pumps are much more efficient than burning fuels for heating. So you will always lower the primary electricity or energy demand, but there's one technology which doesn't do this. And this is a water electrolysis for producing hydrogen. This is much less efficient. So in order, if you start using this as a storage, as a yearly storage, then really your power requirements explode.

[51:00] Guest: And if you look at I think Fraunhofer has just published a study of hydrogen strategy for Germany, and there they claim that just electrolyzers will need between 50 and 80 gigawatts of power. Continuous capacity depends whether you're, if its run continuous or it needs a lot of hours it's only then it's cost effective, but this means 80 gigawatts is the peak load at the moment in Germany. So it means doubling the electricity load just by adding electrolysis and hydrogen. That's a lot. But if you, for example, say, well, we import this hydrogen from somewhere else, like Morocco or wherever. That's like importing oil and gas today. That changes, of course, the requirements on how much wind or solar you would need here. So that really is a huge factor in talking about how much photovoltaics or wind energy you need here in total.

[52:08] Guest: So I think that if you go between 200 and 400 gigawatts photovoltaic, you can make for a nice energy system and you can import the rest of our hydrogen. If you would say that you have to do everything 100% electric energy inside of Germany then you have to go way over such figures. Well, I think that's realistic.

Host: That's not realistic. You mean.

Guest: I think that the last 10 to 15% in the energy system that's really well, it's getting tough. And if you can get that from somewhere else, that would be here beneficial for us. Yeah.

Host: So your personal favorite gut feel a lot of gut feel, of course, how would that? I would our energy system look like in the future, if we had to decide now.

[53:00] Guest: I think we have to carefully design on how much more wind energy we can accept and how to increase that acceptance. I think wind energy, wind and solar public acceptance. And I think there's a price tag to that acceptance. I think you're willing to accept much more if you get more money for it. That's the way it just, we are it's I don't want to say anything bad with that. I think that's the way it goes and I think that's fine.

Host: Yeah.

Guest: And then you don't have to overdo it, but I think there's still some room and there is opportunities, I think for photovoltaics, we have to basically see on every year a house roof. Especially if you look at commercial rooftops, you must integrate for the word tags everywhere, and then we have to see how much we can get into our countryside as well.

Host: Yeah.

[54:00] Guest: I think there's plenty of room. There's plenty of opportunity to do this. And I think in general, also for research of the acceptance topic is very nice and talking about how to design a system that people will think it looks nice. It's also possible. Like I think in a field, a solar system can look nice or you can try and hide it if you don't want to see it. Today we have five facial solar modules, which you can put vertically, which looked different than I think you should take into account. How would they also look like and how it's accepted by the population, which has to see it every day.

Host: Yeah. Cool. All right. So after all these years, you're still optimistic that what mankind or yeah. We'll, we'll make it possible.

[55:00] Guest: I dunno. I don't, I also don't know how much we should be afraid. That's really it, something that I'm completely not sure. I was recently asked by someone, but I really think that in 30 years time we will not be able to sit down and have a drink together. I dunno. Yeah, probably we can, I don't know what the circumstances will be. Will the world look like Mad Max I don't know. Do they have drinks that make mix? I guess so. I don't know how bad it's really going to get.

Host: Yeah.

Guest: And but you must stay optimistic to survive. I think all is there's no point in saying, well, it's not going to work anyhow. And I actually think that it's not like a digital thing. It's not like either we make it or we don't. I think it's, even if you don't meet the 1.5 degree goals, maybe if we go over all the tipping points, I think it's still worthwhile to have energy security from renewable decentralized sources.

[56:08] Guest: So I think we must push this way and there's no other way.

Host: There is no other way. All right. So, basically my last question. So, so what's the one thing do you think the solar industry needs to get to the next level?

Guest: I think we're doing great already. I have recently said in an interview that I think my single biggest misunderstanding was that we need thing photovoltaics in order to ever be competitive with the voltaic.

Host: I was in that as well. Yeah.

Guest: Yeah. Maybe you thought so too. I thought we needed one revolution in order to get there. And boy, have a look.

[57:01] Guest: What evolution has done for us. Like the Silicon photovoltaics people say, I don't know who of them invented it, but might've been takes Dick Swanson. That a Silicon technology is the dinosaur of solar technologies and the dinosaurs are still hungry. Yeah. And I think that's just true. It's, it's really amazing what the evolution of Silicon photovoltaics has done and how much they've driven down the cost. And it's really great work of all the people involved and you can just be grateful to all of them. Who've driven this and acknowledge their great work. And I think, alright, just keep going and keep pushing. And I think solar is such a big business already. It's really crazy. I've just looked at numbers on the employment in photovoltaics, in Germany and other countries.

[58:00] Guest: And I think we have an average of around 400 employees out of a million in photovoltaics now worldwide.

Host: Worldwide. Okay.

Guest: That's crazy. Germany is now below the average, by the way, but that's a different story. China is three to four times the average. So that's the big player there. But it’s really amazing how many people work in this field. And it’s just a great opportunity, a lot of things are happening there and I don’t believe in the revolution of photovoltaics anymore. I don’t think it’s necessary. It would be very interesting to see whether we need tandem cells. But I think only the standard technology will make it there. But that will be interesting too. We’ll see how it’s going to work. But you’re an expert on tandem cells. And that will be good for you, and you have the metrology to look for it and stuff.

Host: Yeah. Excellent. Alright Jens, thanks for taking time today.

[59:00] Host: Must be an hour or so.

Guest: You said we were going to talk 15 minutes?

Host: Yeah, sorry, sorry. Well you talked all the time yeah?

Guest: Ah, sorry, sorry.

Host: Your kids behaved very well. Once in a while, I wasn’t sure if it was my kids or yours in the background.

Guest: I heard mine.

Host: You heard yours? But it all worked well. So hey, thanks a lot. We were supposed to meet again for our every seventh week in solar [unintelligible]. I guess this will also be a virtual meeting, right?

Guest: I’ve done one before and it actually works quite fine. It’s nicer in person.

Host: But it’s definitely cheaper at home. Thanks a lot, Jens. And talk to you soon.

Guest: Thanks a lot Trov. Let’s see if anybody watches up to this point.

Host: Yeah we had fun. See you soon. Bye, take care.

Guest: Bye.

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