Episode Transcript
[00:00:10] Speaker A: Welcome to the EU Energy Projects Podcast, a podcast series from Enlida and France focusing on the clean energy transition for the European Union and the EU Commission funded energy projects that will help us achieve it. My name is Aretid Daradimu. I. I am the editor of the EU Energy Projects Podcast and your host.
In this episode of the EU Energy Projects Podcast, we explore how the EU funded DC Power project is helping to unlock the potential of direct current technologies for Europe's future energy system.
Joining me is Jens Merten who will discuss together with myself the project's vision, technological innovations, demonstration activities and the role that DC solutions can play in improving efficiency, flexibility and sustainability across the energy value chain.
Jens, thank you for being here with me today. And to begin, could you briefly introduce yourself and explain your role within the DC Power project as well as telling us in a few sentences what the project is about?
[00:01:24] Speaker B: Yeah, of course. Thank you very much for inviting me to your podcast. Actually, I'm working at ca. It's a large scale research and developing organization in France which is focused on the transfer of technologies to industrial partners. So. So I am working here with the DC Power Project. It's a European project which I wrote and I'm coordinating now. And this project actually has not only a specialty to focus on dc, but it is also focusing on DC at medium voltage level. So this is something very, very new and complicated. This is actually why we really are happy that we achieved the funding from the European Commission for this.
So what is your role?
Our role actually is the coordination of all this project.
The DC Power Project is a compact project of 10 million and 10 partners only.
And actually in this project we develop a medium voltage DC grid which is powering industrial appliances in the megawatt range.
In order to do this, we need to develop the power electronics components to form this medium voltage DC grid. And for there are different components and for each component there's an industrial partner who's developing it and some of them, two of them actually are developing this with the help of ca and this is actually our role to continue the development of the the power converters which are needed for this medium voltage DC grid.
[00:03:14] Speaker A: Given your overarching, let's say supervisory also role in, in the project, what challenge would you say is the project seeking to address? What's the main challenge and why is this challenge becoming increasingly, let's say, important for Europe's energy transition?
[00:03:30] Speaker B: Yes, so actually the.
We are using DC because we are pushing forward to increase the energy transition in Europe and this energy transition in Europe is also happening via the decarbonization of industry.
And with the decarbonization of industry, actually there is the need to power industry directly with renewable energy sources.
So actually the common AC grid which we have today, it's very comfortable. We can change voltage levels with transformers very easily.
And so this is why we have AC grids today.
But the thing is, when we want to couple DC sources with DC consumers, it's more advantages to couple this directly on DC level and kick out all these inverter and rectifier stuff and we reduce a lot of problems of the implementation of complex energy systems on the sides.
So the challenge is actually here to develop the power electronic components to provide these DC grids. And another challenge will be actually to make them work together so that they form a stable and reliable grid on site.
What I did not say yet is actually the DC power project. We will do a demonstration on a data center site in Greece and we will do the demonstration of an electrolyzer site. So there will be two demonstrators with real scale industrial sites which will be realized within the DC power project.
[00:05:28] Speaker A: When will that happen in Greece? When do you have this planned?
[00:05:32] Speaker B: The delivery of power electronics components is foreseen for March 27.
So from March 27 on, the DC grid will be set up in both demonstration sites.
[00:05:51] Speaker A: Now, speaking of DC technologies, could you tell me why is it attracting renewed attention today? I mean, it's nothing new, but it is attracting a lot of attention lately.
[00:06:02] Speaker B: While DC technology is not used, they are used for charging your mobile phone or to make work your computer or things like this. But actually we are here working on high power levels and on high power levels. Even on domestic power levels, AC grids is the majority and you do not find DC appliances.
So according to the power level we need, there are different voltage levels associated to this DC voltage level. If we are going for buildings or residential applications, it's only 400 volts and there are people doing this. If it's for industrial applications, there has been a large project in Germany, it's around 800 volts.
And if we want to go to megawatt scale industrial appliances like we do in the DC power projects, we have to go further on with the voltage and we have to go beyond the limit of the low voltage level standards. And this limit is 1500 volts. And what we are doing in the DC powered project, we are doing the double.
So we will go at 3 kilovolts in order to have less current, in order to bury less copper. And by this way the life cycle analysis of the grid which is installed will be much better.
[00:07:34] Speaker A: Is this one of the main objectives, let's say, of the project? What other objectives does it have and what kind of outcomes, let's say, are you hoping to achieve by the end of the project?
[00:07:47] Speaker B: Yes, well, actually, one of the outcome is this, that we need less, that we need less material, that we come to a better efficiency. And actually we will demonstrate that the losses for the local distribution of energy will reduce by half, by 50%.
And this will be done within the DC power project. And, and it is very easy to do this actually, because in the data centers we have uninterrupted power supply which, where actually all the energy which is consumed by the data center is transferred by a battery.
There's a rectifier charging this battery. So we have losses in this rectifier.
Then we have an inverter which is taking out the energy. Again we have another conversion loss. And these two conversion losses are permanently active in standard data centers. So if we find a topology where we can put the battery in parallel and not in serious to the powering of the data center, we can kick away these permanent losses. And this is one important step here. It is possible with the DC power technology.
And so we strongly reduce the losses in data centers because we use actually the battery converters only when the batteries need and not 100% of the operation of the data center.
[00:09:28] Speaker A: And that is also a way to achieve energy efficiency, I think. But in general, many modern technologies operate natively on dc.
How can a greater use or a bigger use of DC systems improve overall energy efficiency? And not only when it has to do with data centers, let's say.
[00:09:50] Speaker B: Well, actually what is happening is, for example, if you want to power a drive a motor, an engine, so what we have to drive an engine is we have an AC grid. And this AC grid is connected to an electronic device to drive the engine, which is a frequency converter. And in this frequency converter we have two elements. We have the rectifier which is producing an internal DC voltage. And then we have an inverter with variable frequency which is driving the engine. If this engine converter, this frequency converter is powered with dc, actually we can kick out everything which is dealing with the rectifier. And this rectifier is producing problems on the grids because it's ejecting harmonics because the consumption of electricity is not very, very, not very sinoe.
So actually what happens is that the perturbations which we have on the grid. If we have a lot of frequency converters connected, which needs then a lot of filtering, all these filtering and also the rectifier part of these converters can be kicked out. So actually the DC grids are more simple to design.
And actually also it is more easy for DC grids to connect the PV system. Because a PV system is dc, PV is DC and what is happening, a DC DC supply only needs a small DC DC conversion which is very efficient to connect to the DC grid. If not, we have to go again with an inverter step which is less efficient.
So we really gain in efficiency.
[00:11:45] Speaker A: And with what key technologies or key technological innovations are you going to achieve that? What are the innovations? The key technological innovations that are being developed or demonstrated within the project.
[00:11:58] Speaker B: The key, key innovations are in the first place, the converters which are needed to operate this grid.
So we have four types of converters. We have an active front end which is connecting the DC grid to the AC grid of the utility.
We have DC DC converters for batteries, we have DC DC converters for photovoltaics. And we have appliance drivers which adapt the DC voltage to the distribution voltage grid which we have chosen. So for example, the electrolyzers, if they need 300 volts and our distribution 3kV. So we have to go down from 3 kilovolts to 300 volts and provide here, adapt the voltage level to the consumer. And these, these converters have to be developed. And of course one key is here actually the use of silicon carbide technology.
So these are DC DC converters. But another thing, another innovation which is in this project is actually assure the stability of the grid. So assure, make, make rules and implement these rules in the converter so that there's a stable operation of this grid. This is another kind of.
[00:13:27] Speaker A: Now, interoperability is often a challenge when introducing new technologies. How is DC power addressing compatibility with existing energy infrastructure?
[00:13:38] Speaker B: Yeah, actually the DC grid will be connected to conventional grids with a device which is the active front end. The active front end is a B directional converter and it is connected according to the rules to the grid code of each country.
And it's this one assuring the interoperability with standard AC grids beyond technical performance.
[00:14:07] Speaker A: I would like to ask about the economic benefits that wider deployment of these technologies would bring to consumers, business and grid operators.
Let's talk money a little bit.
[00:14:19] Speaker B: Yes, yes. So when we were told to talk of money, of course everything is also.
It's also depending on Quantities. You know, if I want to construct one converter, it will be very expensive because it will be handmade. It's like with the cars, but when you do a lot of cars or do a lot of power electronic devices, then the costs will go down.
So actually of course we are in a demonstration project and the converters which are developed in this project, they are handmade.
So it's artistic work here.
So this means that actually they are very expensive.
But the idea is not now to drive costs down. The idea is now to make a feasibility study and demonstrate that this type of grid is working. And then once this is sufficiently interesting, it is then interesting to make follow up demonstration projects where then the costs can be of these power electronic devices will be reduced.
[00:15:29] Speaker A: I would like to circle a little bit back. You mentioned Greece. At some point I would like to ask about the pilot sites or demonstration activities, apart from that one that we've already discussed and what they aim to validate.
[00:15:44] Speaker B: So at the pilot sites we validate the objectives, the objectives of the project and one of the main objectives is the reduction of losses.
So we will do some comparison with the standard AC grid distribution.
It will be somehow the baseline measurements and the losses we have when we set up with all this thing in dc. But actually these losses, this is, this is a simple technical measurement.
The, the other advantages there are actually much stronger and difficult to express in money. Because if we want to set up a complex system which the integration of storage and PV and which has to be flexible in design, this is something, this flexibility, nobody is paying for it. You know, it's, it's a, of the site owner to, to go for who he wants PvE.
He has a strong demand and then he can decide if he wants to go for standard AC grids or if he wants to go for DC grids.
And at this moment he will, he will love this flexibility of design and to get rid of all the hassles of power quality of local AC distributions.
So they will be very happy with this and get rid of a lot of hassles.
[00:17:15] Speaker A: And what are the lessons that you have learned so far or the most important of them?
[00:17:20] Speaker B: Well, I think the main lessons they will come and we really go for the demonstration. And also we have a preliminary phase of lab testing which is starting right now in the lab and it is there that we will learn our lessons.
What is clear is that the DC grids is something very, very new. It's something very new and we are very limited in available devices and some of the devices for example, we have to take from the railway sector. And the railway sector has very robust mechanic devices for sectioning the circuits.
But they have the problem that completely oversized and so much too expensive. So we need development of novel protection devices also for the medium voltage DC grids.
And this will be also done by one of our partners who is developing in this project a novel kind of circuit breaker.
[00:18:29] Speaker A: And where do you see the potential for DC applications in Europe or say the greatest potential in buildings, industry transport data centers elsewhere.
[00:18:41] Speaker B: So actually when we want to go to medium voltage DC grids it is for megawatts scale applications. So it is not interesting for office buildings or something like this. There we have to reduce the voltage level of the DC grids. And this is not where we are now positioned. We are positioned on megawatt scale industrial appliances. And there it is very interesting. So one big application is the data centers. And in the data centers the current, the current trend is to go for 800 volt distribution. When we go for 800 volt distribution we still have a lot of current.
And what I propose is to use this medium voltage DC grid as a distribution and then produce appliance driver which go to 800 volt. So this is the data centers. Other megawatt scale applications is electrolyzers, induction furnaces, cement industry with air air heating for example.
Or it's the, the truck charging, charging of megawatt megawatts scale truck charging or even fast charging of standard EVs. These charging stations, they are huge and they're all done in 400 volt AC.
And this is a lot, a lot of copper which could be saved. And these stations, they can become also much more compact and cheaper by using the DC technology.
Also the DC technology has less footprint, so we need less space because we have less converters and less, less filters. And so we need less space. And so we have more space available for charging cars then for then with the standard AC technology.
[00:20:37] Speaker A: That sounds good. Very good I would say. So what regulatory or market barriers still need to be overcome before DC systems can be deployed at the, at a scale?
[00:20:47] Speaker B: Well, this is very clear for we are, we are, we are going beyond the low voltage limit. So actually we are then in medium voltage in the medium voltage regime.
And actually there are not a lot of standards available for this medium voltage regime. And this standardization has to be driven forward in order to, to be able to easily deploy this kind of systems.
And this is now really a barrier even for the demo sites for these systems.
[00:21:25] Speaker A: Now looking ahead, Jens, what would you say success looks like for DC power and what impact do you hope the project will have beyond its official lifetime?
[00:21:36] Speaker B: Well, the success, the first success is that all the converters are working and that the grid is working correctly and, and that also at the demonstrator everything is working fine so that you can then make the measurements in order to evaluate the quality of these kinds of grids.
So for me also a very positive impact is actually to awake interested partners in this technology for complex industrial sites to consider these DC grids or medium voltage DC grids for industrial sites to consider implementation.
And I'm thinking, especially in the decarbonization of industry, there's a lot of things to do there. It's in France, it's actually a defined vector of the energy transition and it may be also the case and maybe in other countries.
So decarbonization of industry is an interesting vector now for the future application of this DC power. And another thing is this rising, this dramatically rising energy demand in data centers, which can be strongly supported with this kind of architecture, which is more efficient than the current trends.
[00:23:00] Speaker A: As we are approaching the end of our discussion, Jens, I would like to ask you a final question now. In our audience as a podcast, we have policymakers, we have industry stakeholders or energy professionals. So if they're listening today, what would you say? What would you like? The key takeaway, the one message from
[00:23:19] Speaker B: the project to be mediocre GTC grids. It's a completely new world.
It's not covered by current regulations, but it is a must for the massive decapolization of industry because we want to eject solar energy directly with the application. And the most efficient way to do this is with DC grids. And if we go to vegawatt scale, we cannot do this in the low voltage regime. So we have to go to media Voltage.
[00:23:53] Speaker A: Thank you very much, Jens for this very interesting discussion. I learned a lot about DC Current that I didn't know before.
[00:24:00] Speaker B: Thank you very much. Thank you very much, Areti. It was a pleasure to discuss with you.
[00:24:08] Speaker A: You've been listening to the EU Energy Projects podcast, a podcast brought to you by Enlit and friends. You can find us on Spotify, Apple and the Enlit World website.
Just hit subscribe and you can access our other episodes too. I'm Aretita Radimo, thank you for joining us.
