Bárbara Freitas-Daniels High voltage takes center stage in this brand new season of Hitachi Energy's Power Pulse podcast. We promise to bring you great content from the brightest minds in the business. We'll discuss challenges, opportunities, and all the hot topics any high voltage enthusiast or anyone interested in sustainability for that matter, is sure to enjoy. In the first episode of the podcast, we want to give you a flavor of the topics we'll cover throughout the season.
Bárbara We needed someone with a deep knowledge of the power grid and all its glory inside out to really tell the story. So who better than the managing director of the High Voltage Business Unit himself? Doctor Markus Heimbach holds an MSC and a PhD in electrical Engineering from Aachen University and an MBA from the University of Hagen. Before joining our company, he was a scientist and a chief engineer at Aachen University.
Bárbara We should add that he was also the MD for medium voltage and later the Transformers business unit. You get the gist of why we picked him for this episode, right? His range of knowledge in this field is pretty incredible.
Sam Dash Welcome to Power Pulse. This season we explore the world of High Voltage. I'm your host, Sam Dash, and for our first episode, I'm speaking with none other than Markus Heimbach, managing director for High Voltage Products. Hi, Markus. Hello. So, Markus, first things first. I hear you are a keen cyclist. Do you race or take part in events? Markus Heimbach It is correct that I am a cycler. That I am as well doing it mainly because I enjoy it and as well, because to to keep the shape.
Sam Yeah, yeah. Markus But for sure, from time to time I'm going to events like the Bodensee Bike Marathon, or the Lake Constance Bike Marathon in English. And by the way, the day after tomorrow, I'm trying the Amstel Gold Race goes to my hometown. Sam Oh, wow. And so what does that consist of? How long is that? Markus 150km. So it depends how fast you are. So I hope that I will go through it with an average of a bit more than 20km/h.
Sam Wow. Fast. I suddenly have this image of you in an office on a stationary bike, powering the whole office building with your energy. Markus Yeah. The problem is that the human being is not the most efficient way of... Markus Of generating this electricity. So you would do it maybe for fun. But I don't think it's really efficient to do it to power the houses.
Sam Yeah. So, Markus, before we dive in, I'd love for you to help us with some definitions. The term energy transition is a term I've heard used a bit here and there. Can you give our listeners and me, for that matter, an overview of what energy transition means in general terms and then specifically for high voltage?
Markus Sure. The term energy transition is a translation of the German word Energiewende. Energiewende started after the Fukushima event, when the German government decided to shut down all the nuclear power plants within a certain time period. Sam In response to Fukushima.
Markus In response to Fukushima, because once all the safety and environmental topics which were resulting out of it. And while they were doing it, you need as well to replace this energy, which is generated by the nuclear power plants, by something else. And the idea was to replace it by renewables. And then when through the Kyoto Protocol and other things, the pressure on the decarbonization came more and more.
Markus The energy transition term was as well used and more and more used for the overall decarbonization, where the whole world is embarking on. Sam I see, so everyone joined in on that effort.
Markus Everybody is joining in on that effort, and its meaning that we are trying to replace the traditional mainly fossil fuelled power plants, but as well the nuclears by renewables, right. And this is then driving decarbonization of the generation. On the other hand, it is not only the generation which needs to be decarbonized, it's as well the consumption. Sam Right.
Markus When you, for example, look into the cars, a combustion engine is as well, has a carbon footprint. And this is more and more replaced by, electric vehicles. When you look into fossil heating, like gas heating or oil heating, the idea going forward is more and more to use heat pumps, right? All of this is putting additional load into the grid. Sam And so energy transition exists in a multitude of different contexts. Is what you're saying, right?
Markus It exists in multiple contexts. For us it means that the whole world is becoming more electric, which for us, as high voltage products or as Hitachi Energy, means that the grid needs to be more and more enlarged. The grid needs to be stronger because there is more electrical energy transmitted because of the overall load increase, or as well because the load is shifting from other things into electrical load.
Markus So from that point of view, you need a grid, which is becoming stronger, meaning has more capacity, is extremely reliable with now less stable generation. Because when you look into, for example, into a nuclear power plant, it is an extremely stable generation, like a coal power plant. You know exactly what electricity you are generating, while when you look into a renewable, you have the fluctuation.
Markus You don't know if the wind is blowing for the turbines. You don't know if the sun is shining, shining for the solar. You need to have some forecastability. That means also that the grid is not only needs to become stronger, it needs as well to become more smarter, more intelligent, more flexible, because you need to react to the different sources you have.
Markus And the grid is there to match between the consumption and the generation. And this needs as well to be controlled to the grid through the digitalization. And last but not least, you need as well to make the grid as well, which is an enabler as I explained for the green world, for the decarbonized world. Markus But the grid itself needs to become more greener. And this I'm going to explain in one of the later discussions, we have. Sam Great. So, Markus, why do we need high voltage?
Markus It's very simple. The higher the voltage, the lower the losses. If you, for example, have a normal distribution like here in this building, you have 230 or 400V. And when you are here in Europe, the highest transmission voltage is in the range of 400 kV. So there is a factor of thousand in between. However, if you transmit the same power at 400 kV and at 400 volt, you make out of the factor thousand, which you need to invest into the voltage, a reduction of the losses by 1 million thousand to the power of two, because the higher the voltage, the lower the current, in order to transmit the same amount of power.
Sam I see. So it's about efficiency, more or less, is that right? Markus It's about efficiency. You want that most of the power you are generating in the power plant or in a solar plant or on the wind turbines that most of the power reaches the consumer. Sam With as little loss as possible. Markus With as little loss as possible. Sam ...on that journey.
Markus Which is as well as part of the decarbonization of the, of the network. And for that, it is absolutely mandatory to increase the voltage because with 400 volt, you will basically, you would if you transmit with this, you will only create losses. Sam Right. Sam So pivoting a little bit in terms of the history of the power grid, I'd love for you to explain, for our listeners, the geography of the grid, the infrastructure system that powers our homes and businesses.
Markus Yeah. The grid itself, as I mentioned before, is the connection between the generation and the consumer. And the consumer is a the power and then the houses. Yeah. And during the, discussion just a bit before I explained why we need the high voltage. And that is already the answer about the part of the geography meaning we transmit the big power, the bulk power over long distance with as a high as possible voltage.
Sam And those are the power lines that people see sort of dotting the landscape.
Markus These are the huge power lines that the people see in the landscape. As mentioned, the main transmission here in in Europe is done at 400 kilovolt. Right. And when you have these 400 kilovolt and this is I've just told you the good thing about it, the losses. But on the other hand it's a huge effort to put the system from 400 volt into 400,000V, because you need a lot of insulation, you need a lot of distances, you need to lot of investment as well to generate that grid. Sam Right
Markus Yeah. Or to create that grid. And this is one for the long distances. And then we are approaching more and more of the cities and when you come to the city you have less space, Sam Right. Markus By the way, this is one of the reasons why we invented in Hitachi Energy the gas insulated switchgear, which is a very compact size into the cities. Sam So it's ideal for urban areas where you don't have as much space to use.
Markus Correct. It's ideal for that one. And when you go into the cities as well, you have lower distances and you cannot afford to go always with 400 kilovolt or up to 400,000V to the cities. Right. Sam Because safety is also.
Markus Safety is an issue. Space is an issue. You need to go down with the voltage in order to overcome the disadvantage what the high voltage have. The more and more you go then into the rural area or into the streets, you go down to medium voltage until it enters into the household at 400 or 230V. Sam Right at a much safer speed.
Markus I would not say it's safer, but in a much more handable speed, because in the end of the day, it's as well a lot of space. You would waste if you put only small currents on a 400 kV. Sam Sure. So getting a little bit more into the history, how old is the power grid in general or does that differ I guess depending on the country and the region.
Markus For sure, it depends on the country and the region. But it is roughly in the end of the 19th century, it started when they started to to transmit energy from one point to an to another point. It was not really a grid in the beginning. It was more of a point to point direction. But in the end of the day, that was the topic and there was a big debate.
Markus If the discussion would be between an alternating current or between, a direct current. So AC what we say, or DC and there was a lot of fights and history at that time, the alternating current, the AC was winning the game because of the more flexibility you have with the AC. And when you mean flexibility, it means that the AC and the transformer principle is to change from voltages from different voltage levels.
Markus You need a transformer and this is coming along with the alternating current because you are not able to do a transformer when you do it in direct current or in DC. And there's another topic is when you talk about an AC network, you can have as well, circuit breakers. Sam Right? Markus Because with 50Hz, the the current crosses the zero line 100 times in a second. and you only are able in a efficient way and in a smart way to interrupt the current if you take it at the current zero.
Sam Right. That makes sense. Markus And that is basically the principle why the alternating current was winning the game in the past. because you can apply the transformer and you can as a main safety element, use as well the circuit breaker. Sam So is direct current still used? Markus Direct current is now coming back. And I would say bigger than ever or larger than ever. Sam Oh, interesting.
Markus And the reason is that whenever you transmit a direct current energy of always a direct current, you don't have reactive power. Sam Why is that?
Markus Because and this is a little bit technical now, because, a transmission line behaves somehow as well as a capacitor. And a capacitor means that you are charging a capacitor and you as well unloading it. Okay. Which is not a big problem, but it's a problem because this current overlays the current which is used in order to transmit the power.
Markus Right, right. And this current is then in the transmission system creating an additional loss. okay. Yeah. When you have, for example, a cable which behaves even more than, as a capacitor than a transmission line. You went with a couple of ten kilometers. You are only charging the cable any longer and you cannot transmit anything. Sam Okay.
Markus And when you think about now, all the wind farms which are now coming into the North Sea, which are coming around the coast of China in the US east and western coast, these wind farms are a couple of ten kilometers away from the coast. Yeah. So. And if you would transmit this power generated at the wind farm at AC, you would only charge a couple, right?
Markus So that's why it is more efficient, for example, to, to adapt or to use the direct current in order to transmit that energy onto the shore. Sam So how did different countries end up having different voltage requirements for their power grid. Markus It's always a lot about history. Yeah. And it's about distances.
Markus For example Europe is big from a population point of view but it's not the largest from a distance point of view. When you look into US and then you look into China and as well, partly in India, they are using more distance higher. They need to transmit over longer lines. And this you can easily say you more energy you need to transmit over longer distances. Markus The more efficient it is to use higher voltages. Sam Right. Because it has farther to go.
Markus It has farther to go. And as I mentioned, the loss is the lower the higher the voltages. Sam Right. Markus But this doesn't come for free, as I mentioned too. Sam Right. It takes a lot of resources and thought. So I imagine this is connected. But can you explain why some countries have 50Hz and others 60Hz? You sort of touched on this a little bit earlier.
Markus The reason is in the beginning there were a lot of frequencies used. and there are two competing things. Yeah. The one is that a transformer is needing less iron for the core and this much less from a weight point of view and much cheaper. The higher the frequencies, the higher the frequency. the lower is the CapEx or the weight or the effort you need to put in the transformer, because the transformer is generating the voltage through the changing current, and the higher the rate of change, the rate of rise or whatever.
Markus Yeah, the more voltage is generated. So you need less iron in order to, to conduct the magnetic flux. Sam I see. Markus Right. And you have a very prominent example for that one, which is the aircraft industry. When you have the board net of the aircraft, it is much more important that you have less weight compared to the efficiency of the system. you go with 400Hz just to reduce the, the weight of the transformer. Sam Right.
Markus On the other hand, you want to have a generation, a generator or whatever. It is not always to be too fast in turning or whatever. Sam Why is that? Markus Because the faster it's the rotating. And in the beginning it was more on the hydropower plants, then it is much more effort. You need to control the speed and the rotating speed. So from that point of view, it was even more interesting on the former generation side to have lower voltages. Right. And then they came to a compromise.
Markus And the compromise, somehow here in in Europe is a 50Hz in, in the US it is or the North America is 60Hz. And then you spread it out. So Saudi Arabia adapted to the US is 60Hz in Japan, which is very interesting, was on the one hand side with GE which is 60Hz, and on the other side with Siemens, it is 50Hz. Markus So you have then basically the full history going around the world. Sam Do you think everyone will ever get on the same page?
Markus No, I don't think so because what will happen more and more is, as we said, that we have more DC. Yeah. And that we have more power electronics in the network which are as well able then to couple the different networks with HVDC connections so that it is not so important if it is 50 or 60Hz on the one side, on the other side. Sam The compatibility sort of becomes negligible, more or less.
Markus Correct. Markus And and just to mention one thing, which is unfortunately, interesting, but not a good news is the 50Hz and to 60Hz is unfortunately in the range where the heart is the most vulnerable. Sam Explain that to me. Markus I don't I miss the English word when you can with 50Hz or 60Hz or you can you can test how how well a human being or can anybody withstand a voltage at a different frequency. Sam Oh, I see.
Markus And the withstand capability of the human body is unfortunately the weakest at the 50Hz to 60Hz because it is impacting the rhythm of the heart. Sam interesting. Markus So you get this way that you have extremely high frequency in the heart, and that is unfortunately not helping the overall system. So we need to be even more careful when we are handling our system with the 50Hz and the 60Hz.
Sam You mentioned digitalization earlier. We live in an ever evolving digital world. How is high voltage keeping up with the times from a digital perspective?
Markus For the digital has as high voltage has a lot of dimensions for us. One example I would have from an production operations point of view is what we call the digital passport, where we are now able to trace all the products, all the components, all the suppliers within the digital passport system. And when we go into the, the field later on when we have, a circuit breaker installed, three years later, we go back there, we can, through a barcode, understand, or QR code, we can understand the full history of that breaker.
Sam Right. Markus We know what material was used. We know who was a supplier. We know what was a torque applied. We know how it performed during the routine testing. That we will know, which is a huge effort and which will be impacting the reliability of our products. Sam Sort of provides a, sort of digital encyclopedia for all these different components. Is that right?
Markus As we say, exactly as we applied, for our we call it passport. It's in the end of the day, you know, exactly what was done there. This is one example for digitalization. Another example is that we have, for example, control switching or point of wave switching. A circuit breaker needs to hit the the current zero in order to switch the current.
Markus Yeah. The circuit breaker is a mechanical system. The interruption is done by the arc. but it depends very much when the arc is starting. How far away is it from the next current zero? so this new you can understand this is a very high mechanical topic. Yeah. What is as well an electric and digital topic to forecast the next current zero.
Markus So this is where we use this work digitalization. Because when you know, when the next current zero is coming, you need much less effort or you are switching on the one hand, or you are switching much safer than you do with the normal switching. And another example, for example, is our installed base.
Markus Is or predictive maintenance we know through the digital thing is if the gas is leaking, what is the decomposition of the gas. And we can as well to digitalization predict the lifetime of the equipment. What we as well know when the service people need to go there and look at the equipment in order to prolong the lifetime, or in order to make sure that the equipment is safe.
Sam And part of the current discussion around digitalization is the use of AI. Do you see, the use of AI coming into the world of high voltage?
Markus It is coming for sure into the world of energy. It is as well coming into high voltage. The topic is that our equipment mainly is only operating when there is a short circuit and empty things. So to to predict the maintenance of this equipment, you need to have not too many possibilities to take the data from in order to predict the future behavior. Markus But for sure, this the future and this is a dream for all of us.
Sam Got it now going back to the grid, how often does equipment in the power grid need to be replaced? Markus That depends a lot, but usually we are creating and we are building equipment which is reliable and which is there to remain for decades. I would say after 30 to 40 years, even 50 years, and maybe an extreme case even to 60 years. I saw that once or twice. However, it is as well that the technology might change, or that you are looking into a substation or into a transmission line.
Markus which needs now to fulfill different demands. Sam Right? Markus Maybe you have more consumers and you need to upgrade the transmission line or the substation from 200 kV to 400 kV. Then you need to replace it. But from the overall topic point of view, I would say you can say that the lifetime is in the range of some 40 years. Sam And do you see the possibility of making these grids more sustainable from your viewpoint? Is that something that's feasible?
Markus That is exactly the topic where I was referring to in the first question. We need to have a greener grid. We are using in the high voltage, a beautiful gas from a technology point of view, which is called SF6, sulfur hexafluoride, which is the best gas you can imagine when it comes to insulation and when it comes to interruption, as I mentioned, we need as well the circuit breaker to interrupt the current, especially the with the fault current, short circuit current.
Markus And when you interrupt the current, you need a gas which is cooling down the arc. The interruption is being done by an arc and you need to have a gas which is cooling down the arc as fast as possible in order to withstand the voltage after the current zero. Sam Yeah, right.
Markus And this gas on the other hand, so beautiful from a technology point of view, has a huge advantage. It's the most potent greenhouse gas we know. It has a global warming potential of 25,000 meaning 25,000 times CO2. And when you look into that one, it means that every leakage we have in leakages, you have naturally to have as well maybe in the process you have a problem. Markus Every leakage is creating somehow an environmental case. Sam Yeah. A detriment to the planet.
Markus Yes. And and that's why our industry has the obligation to get rid of the SF6. Sam Right. Markus And we are now doing this one in order to replace it SF6 we call it EconiQ in order to have an SF6 free gas, a gas mixture to be to be more precise, which is then having the same reliability. But you need this much better environmental behavior, but as well the complete scalability from maybe from 10 kV up to 400 kV or 1000 kV as SF6 had.
Sam So you've sort of touched on this already, but where do you see the future of replacing SF6 going? Markus I see the future of SF6. We have a lot of jurisdictions in around the world, and for example in Europe, in North America, I expect within the next decade that the input of SF6 into the new system through new equipment will be basically banned.
Sam Right. Markus So you will have SF6 free solutions like our EconiQ solution, which is then doing the same job, but with a little bit more effort. Markus The reliability is there, the scalability is there without having the harm on the environment. Sam Right.
Markus But still, you still have a lot of equipment in the network. As we said, it's some 40 years. So if it we are phasing out, you have equipment which is staying then for another 30 years after the phase out. And we need as well to think what we can do about that one. Markus And here our idea is, or what we have already tested is that we take the SF6 out of there and replace it by an eco-efficient gas. Sam So using the same equipment, you take the SF6 out of the equation and replace it?
Sam Correct Markus So because also this it's not only the decarbonization is not only with the new equipment, it is as well with the existing and installed base which we need to attack. Sam Right. Thanks so much for joining us today, Markus. You've provided a really robust foundation for our listeners and for me. Thanks so much for tuning in to this first episode of Power Pulse, our season on High Voltage. Until next time.
Bárbara And that's it for today. We'll be back soon with some more great content. But before you go, remember to give us a follow so you don't miss an episode. Thanks for tuning in. See you soon! This episode was brought to you by Hitachi Energy. Created and introduced by Barbara Freitas-Daniels. Content and script writing by Cassandra Inay. Bárbara Guest speaker Doctor Markus Heimbach. Hosted by Sam Dash. Produced and edited by Creative Chimps.