Take us his little bit into your Green factory. What do you produce, Mr. Müller?
Andreas Müller: We focus on producing ventilation ducts, steel construction components, but also on a large scale finished energy modules for public utilities, for energy supply, that is turnkey energy solutions in the container, in the energy module. We have just under 200 employees at the site, from engineers to designers to commissioning, and that was our motivation to produce this in a climate-neutral way right from the start.
You have a high energy input in the company because of your large machines, and in general a factory with 200 employees has to be powered by energy. How did you approach it and what are the potentials?
Andreas Müller: We have large machines such as lasers, the paint shops and we have made a very intensive analysis, so in the end a forecast, how we estimate the energy consumption via the digital twin. Then, within the framework of a digital twin, we looked at how much we can map with photovoltaics? What energy do we still lack? How can we generate it at the site? And that's how we actually approached the issue. So, as I said, a clean analysis and then we look at how we can best integrate solar power - with the battery, with the heat pump, with the CHP with eco-gas as a back-up. Of course, if there is no wind and no sun, we need further supply. And that was actually the motivation. And then, of course, to make energy more flexible. That means we have plants that only run in excess electricity. We produce nitrogen and welding gases only in excess electricity. We operate our coating systems only in excess electricity. But also the charging of cars: We have almost 30 charging points at the site. We charge the cars according to load management, which means that when the sun becomes more, the cars are charged more, and when the sun decreases again, the cars are charged less. So ultimately we have a stationary battery, but as we expand our e-fleet, we obviously see the cars as energy storage.
Can you clock in excess power? Do you use weather forecasts for this and know when there is a lot of solar power available to be able to produce?
Andreas Müller: Well, we have several tools. First, we have the weather forecast, we see the energy preview. But since the plant is relatively generously dimensioned with 1.5 megawatts and we see the whole day areas as energy areas, we usually have so from eight, nine o'clock electricity surplus. Yes, and our plant has a consumption of between 150 and 250 kW, and we usually have a solar surplus from half past nine or half past nine. And then, of course, you can start regulating. And especially such topics as the production of nitrogen for our lasers, we can operate very variably, but also lacquering activities. We only have three, four hours where we have to paint a day, sometimes one day not at all. And in the meantime, people have a good assessment of the energy lamps in our company, but ultimately we have also gained very good experience with our entire production planning. Many companies have energy flexibility options. But the first step is actually to set up an energy management system. First of all, we have to understand what can be done at the plant, and that's where we have learned a lot. Yes, we also ramp up the ventilation system on a modular basis, so I don't need to start earlier with 50,000 cubic meters of air when no one is in the hall yet, but we actually ramp up the ventilation systems slowly and then you really start to look at what you can save. So these energy management systems are really not only there for flexible operation, but also for saving energy. If the whole thing becomes transparent, then from my point of view you can save 10, 20 percent in many factories, just by recognizing consumption, where it ultimately goes, standby losses of monitors and and there are many, many small issues, there 500 watts, there one kW. But we said, if in production one kW means nothing anymore, why should anyone turn off the lights in the house at all? So, the motivation simply has to be to look at every kW even in industrial companies, otherwise the house builder can leave everything burning day and night.
Marco Krasser, you have built up a holistic system with your Stadtwerke Wunsiedel. Do you also have energy traffic lights or how do they deal with their energy network?
Marco Krasser: Well, we do not have energy traffic lights in the sense. Of course, we monitor our networks online and also digitally. However, we have made more than 20 years ago on the way to the energy future. We deliberately didn't call it a turnaround, because we don't want to turn back, but we want to look to the future. We set out to build a decarbonized system across all sectors and began 20 years ago with energy generation: Photovoltaics, then also the issue of biomass and wind. We are now the largest wind miller in the county. Then followed by electrolysis, which was built in 2015 / 2016 at least once, with corresponding hydrogen CHP units in advance. We have used the topic of biomass by creating two large pelletizations, because - and this is the background - we just assume that we have to move away from efficiency thinking and towards overall efficiency thinking: not to produce waste, so also not to produce waste from the energy industry and thereby to use the possible and the existing infrastructure as efficiently as possible. On the subject of efficiency-utilization ratio, maybe just a small example, because that helps us if we improve a fossil power plant, the electrical efficiency by one percent. Everybody shouts "hurray," but still we destroy more than 30 percent of the primary energy sources used through the roof by not using the heat. It is much better to operate a biomass cogeneration plant with perhaps 17 percent electrical efficiency, but with a total efficiency of almost 100 percent, because we use the waste heat, store it and then turn it back into energy. Because no company can afford not to produce in winter when the wind is not blowing and the sun is not shining. And that's why we have to transport the energy volumes - and that's the biggest challenge we face - the large amounts of energy from summer to winter. This can be done, on the one hand, via biomass and, on the other hand, of course, via molecules, via electrolysis and also via battery storage. All of these systems are installed and networked with the digital twin, so that in the future we can also network with the next network levels or with other municipal utilities that think in a similar way, in order to balance potential and demand accordingly. In other words, a decentralized system that can be organized centrally, but allows each individual unit sufficient decision-making freedom and intelligence to manage the requirements that arise from the overall area.
So you first analyzed the exact needs?
Marco Krasser: Exactly, we started in 2001 to set up a so-called energy development plan, which was also geographically networked. So what potentials do we have? So on the one hand to develop the potentials, but on the other hand of course also the needs. Of course, we must not forget that needs are constantly and continuously changing. Other heating systems, mobility, all of these topics must be examined across all sectors and the infrastructure must not be overburdened. So we have power grids that are the way they are. The investments have to be decided wisely, and that was our approach. And yes, on the basis of this potential analysis, we have tried to successively develop the potential, to produce excess energy and then to install the storage facilities. And that's where the biggest stumbling block is. As long as the politicians, from my perception, do not understand the integral calculus or cannot explain it to me, and that power and work are linked over time, it will be difficult if we operate an "energy only" market system that happens on the copper plate, which does not exist. And that was the challenge, just to install that in the grid system that we have available and responsible for, so that generation and consumption coincide for as long as possible, but also to develop business cases that make sense from an operational point of view, which may be far away from the requirements of a future energy economy.
Mr. Zösch, how do you handle the storage problem in your Stadtwerke Haßfurt?
Norbert Zösch: We are a municipal utility where we have also massively expanded renewable energies for quite some time. We have so 30 MW wind power in the network with us on the 20 kV level, 20 MW photovoltaic capacity, a biogas plant, where we are also involved and just the power-to-gas plant and now also larger battery storage. So I wouldn't like to talk about the energy traffic light, because there are times when it's red, and then you have to stop. I would rather talk about an energy traffic circle. The one who can deliver always feeds in, and the one who has too much takes in. That you couple these different systems together, which is a very big challenge. We already have over 200 percent renewable energy here in our country. So we're moving in a timeframe of what Germany is looking at 2040, 45, 50. And what hinders us the most is that we have to link all these systems together. Hardly anyone on the market is capable of providing us with such massive support, and if they do, then only at high cost. So, of course, everything that is newly developed is always more expensive, and we would like to receive support by regulating all these energy flows, for example, yesterday on Whit Monday: a lot of photovoltaic power, low demand in the grid, so energy must be regulated back and there is, of course, ideal runtime of power-to-gas again. Now, of course, hydrogen can be used for heat or for mobility. Now in the summer, in the heat, the hydrogen benefits are manageable. Long-term storage is possible with hydrogen, and short-term storage with batteries. Only the batteries - and we are experiencing this, although we now have over 13 MB of storage capacity in our network, i.e. our own storage capacity - is still relatively manageable. On a day like yesterday, the storage is full by twelve o'clock, one o'clock at the latest, so you need a lot more. But investing everything is of course difficult, even for a smaller company. We have built many free-field plants ourselves in the meantime and of course needed a high investment for this. We need the municipal banks, which of course also reach their limits when any credit lines are exceeded or come close. Because, after all, the background means that you don't have to buy energy from somewhere else if you generate it yourself. However, with the disadvantage that it is generated when the sun is there, when the wind is there. And when there is no sun and no wind, we naturally need a stable supply, and we also have a hydrogen CHP unit that can supply heat and electricity again with 100 percent hydrogen. So the systems are all there, but linking them together in such a way that we can operate a smooth traffic circle is the big challenge.
