5 questions for Wilhelm Appler

Wilhelm Appler is Energy Policy Manager at 50Hertz. He was part of the team that supported the Energiewende Outlook 2035 study that will be discussed in this interview. Wilhelm joined 50Hertz in January 2013. He is holding a master’s degree in political science and economics.

1) 50Hertz has just published an Energy Transition Outlook for the year 2035. What are the broad questions it seeks to answer?

Germany's energy transition is making great progress - however, the speed and shape of its further evolution is uncertain at this time. With our Energy Transition Outlook for 2035, 50Hertz ventures a look into the future and seeks to answer the question: "What will the electricity supply look like in 2035, and what kind of grid will it require?" The study identifies reasons for the need of grid reinforcement as well as options of choices and decisions for society and politics.

2) You were looking at five different scenarios and how they would affect future grid development. What are these scenarios?

We described five possible development paths of the energy transition as long-term scenarios and the effects on the power grid were studied: Firstly, we had a look at a strongly decentralised prosumer-oriented energy transition with a strong increase in small solar power and storage units, secondly, we examined a competitive energy transition with a substantially large share of wind power at locations with high yield, and thirdly, we looked at an energy transition with the technology mix as determined by the EEG (German RES development law). A delayed as well as an incomplete energy transition were also studied. In addition, we performed sensitivity analyses to see how the quick decrease of lignite-fired generation as well as the construction of gas power plants and small storage units would actually affect grid development.

3) What were the most striking results of your analysis?

We were surprised about a whole series of findings. The need for transmission grid development varies significantly between the different scenarios. Yet, there is a robust set of “no-regret” measures necessary in all scenarios. Nearly all grid development measures currently planned by 50Hertz are required in each scenario and sensitivity analysis. This set of measures is necessary even in the sensitivity analysis with an increase in gas power plants in Southern Germany or a strong decrease in generation from lignite. Even if the energy transition is characterised by decentralised solar installations and small battery storage units, the need for transmission grid development remains necessary – maybe that’s what surprised us most.

We also found that a greater need for grid reinforcement is not synonymous with a cost increase. Wind power is the main driver for expansion, however its low cost electricity production can compensate the grid development costs – especially if new wind turbines are constructed in high-yield locations.

4) And which lessons do you draw from that?

The findings encourage us to continue our well-planned grid reinforcement programme even though there are many uncertainties. The 50Hertz grid area is already one of the largest electricity exporting regions of Europe and will consolidate this position in the future. In the north and east of Germany, significantly more electricity will be generated than consumed in the long term. Therefore 50Hertz’ planning of the future transmission system is very stable. And another lesson we learned: the study shows that grid development in the 50Hertz area can be almost entirely implemented by expanding and reinforcing existing lines. This is a decisive point regarding costs and acceptance.

5) You attended the RGI extreme scenario workshop this month, which will ideally be the start of a longer discussion on the topic within RGI. What would you say are the most relevant open questions that should be addressed within this RGI work stream?

For me personally, the extreme scenario workshop provided a lot of helpful insight. The different comments and questions on our study allowed me to better understand how other stakeholders perceive the study (for example would it be interesting to test the influence of different European factors on our national grid).

In my opinion, RGI is doing a great job bringing people together and letting them share their findings and studies. By discussing different approaches, all members can learn from each other which scenarios are interesting and worth testing. As we drew helpful lessons out of the discussion and the presentation of Swissgrid, I hope that we were able to give an impulse that might inspire others.