Interview: Prof. Dr. Bruno Burger, Fraunhofer ISE - Current Developments and Challenges of the Energy Transition

Interview: Prof. Dr. Bruno Burger, Fraunhofer ISE - Current Developments and Challenges of the Energy Transition

We at Kyon Energy had the opportunity to talk in an interview with Prof. Dr. Bruno Burger about the current developments and challenges of the energy transition. He is Senior Scientist at the Fraunhofer Institute for Solar Energy Systems (ISE), energy expert and initiator of the energy charts.

Kyon Energy: What is the current annual demand for electrical energy in Germany and how has it changed in recent years?
Prof. Dr. Bruno Burger: In 2022, we had a gross electricity consumption of 550 TWh. The following table shows the changes in consumption over the last thirty years.

Where do you think it will go in the next few years - especially as the electrification of the heating and mobility sectors progresses?
Electricity consumption will increase as a result of sector coupling, partly because we are electrifying sectors such as transport and heat. Electricity generation will also have to increase accordingly. Fraunhofer ISE forecasts almost 1,400 TWh of electricity in use by 2045 (see figure).

By 2030, Germany has set itself the goal of sourcing 80% of its electricity consumption from renewable energies and gradually shutting down power plants that use non-renewable primary energy sources. Currently, the share of renewables is around 50%. Do you consider the government's targets to be realistic?
German government's targets are realistic and are also very much in line with our calculations.

How do you assess the current progress of the energy transition?
After losing almost 10 years due to the electricity price brake from Ministers Altmaier and Rösler, we have a lot of catching up to do. The current government is doing everything it can to ensure that the energy turnaround progresses as quickly as possible. In 2022, a lot of groundwork has already been laid. 2023 must now show that the targets are achievable. The expansion of renewables is probably progressing faster than the expansion of the grids.

In your view, what are the biggest challenges to be overcome in this necessary transformation of the electricity infrastructure?
The biggest challenge is not the technology. We've already come a long way there. I see the challenge in getting the entire population involved in the energy transition and motivating them to do so. The current dispute in the political arena shows that the population and some politicians are no longer able to keep up with the planned pace.

How can the integration of renewable energies into the existing power grid be improved?
We need more power lines from north to south. Unfortunately, Bavaria had blocked this expansion for a long time. But now things are to move forward. In the grid, we need short-term storage (battery storage) to be able to store the midday peak in solar power generation. In addition, more data and measured values are needed to optimize grid operation. For times with high shares of renewable energy but too little transport capacity, we also need a way to limit power flows abroad.

What do you think needs to change so that we can master the energy transition?
We need a clear commitment from all parties to the energy transition. The constant discussions about imports of hydrogen and e-fuels are paralyzing us and keeping us from doing our work.

In recent weeks, the German government has once again placed greater focus on the expansion of renewables and wants to drive this forward more intensively. How much installed PV and wind capacity do we need in Germany to reach the 80% target?
The German government wants 215 GW of solar, 115 GW of onshore wind and 30 GW of offshore wind installed by 2030. This coincides very well with our calculations.

What annual expansion rates do we need to meet for this?
For solar energy, the expansion rates will be increased to 22 gigawatts (GW) per year. The capacity of onshore wind energy is to increase by up to 10 GW per year. (BMWK)

Already today, a lot of electricity from renewable power plants is curtailed because the grids are not capable of absorbing it locally. In addition, above a certain installed PV and wind capacity, there will be more and more times when renewable electricity covers the entire load in Germany. What role do you attribute to battery storage systems here?
Battery storage is very important for short-term balancing between generation and consumption. That's why we need to expand them strongly by 2030.

What storage capacity do you estimate is needed to achieve the 80 % target? (In terms of large-scale stationary storage)
According to our calculations, we will need 250 GWh of battery storage by 2030. Of this, approx. 150 GWh are mobile batteries and approx. 100 GWh are stationary batteries.

What measures should politicians and industry take to further promote the expansion of renewable energies and the use of battery storage?
First of all, all the hurdles that have been built up over the last ten years must be removed. This process is already going very well. The governing political parties need to make a clear commitment to renewables and not keep steering the discussion toward old technologies (nuclear, combustion) or new technologies that are not yet available (SMR, nuclear fusion). These discussions cost a lot of energy, unsettle citizens and slow down the energy transition.

There is a lot of talk in politics about the use of "green hydrogen". This is to be produced with electrolysis plants and later converted back into electricity with fuel cells or in gas turbines. What is your opinion of this approach? Is implementation by 2030 realistic?
According to our calculations, we have to concentrate on adding wind, solar, batteries and grids by 2030. Only then will we have sufficient surpluses for electrolysis to produce renewable (green) hydrogen. However, we will first use this in industry as an important raw material. Only from about 2040 will we have enough hydrogen for reverse power generation. By the way, I do not participate in the color theory of hydrogen. It only serves as an obfuscation. Green hydrogen is renewable hydrogen and blue hydrogen is fossil hydrogen. The color blue absolutely does not match the fossil origin of the natural gas from which the hydrogen is to be produced.

In our view, the efficiencies for this type of electricity storage are too poor to temporarily store short-term generation peaks and return them to the grid a few hours later. We therefore believe that greater load flexibility and more high-efficiency short-term storage are needed. How do you see this issue?
Yes, we see it that way, too. Short-term storage is important first. They store solar power from midday into the evening hours and wind power from the night for the morning hours. At the moment, the addition of battery storage is increasing very rapidly. If it continues at this pace, the capacity of battery storage will be greater than the capacity of pumped storage in just two years.

What role does the research and development work of Fraunhofer ISE play in the implementation of the energy transition and what projects are you currently carrying out?
Fraunhofer ISE is working on many different technologies for the energy transition, including the development of solar cells and solar modules, inverters, charging infrastructure for electric cars, control technology, power grids, heating concepts and heat pumps, building technology, solar thermal power plants, battery technologies, fuel cells and electrolysis, system simulations, and many more. We also support industry in decarbonization, both in the heat and electricity sectors.

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