14 April 2023


Grid congestion Rooftop Solar Grid Operations enexis Novar

Overcoming Grid Congestion: Clearing the Road to Connect New Dutch Solar Capacity - Key Takeaways

Author: Lorena Nieuwenhoven (Solarplaza)

During the webinar this Wednesday (12 April) on the topic of Overcoming Grid Congestion: Clearing the Road to Connect New Dutch Solar Capacity with Wannes Devillé, Senior Grid Specialist at Solarfields and Gertjan Mulder, Portfolio Director at Enexis, answered various key question on the current state of the Dutch energy grid and how this impacts the increase of renewable energy in the system.

Gertjan provided the grid operator’s perspective on what factors play a role in running an efficient system and the increasing need for more capacity in our network - such as location and demand factors. He also began by assuring the audience that Enexis is not against solar generation in general, or solar parks in particular. The Dutch grid operators are doing everything they can to further grow solar generation. Of course, building faster remains an important pillar in this.

Wannes complemented this with his experience as a developer, asking the hard questions on how to ensure renewable generation growth in an overloaded system. How to minimize the barriers and bottlenecks that are currently casting a shadow over new developments. He also showcased examples of Solarfields’ experience in the market by providing key stats on projects like Vloeivelden and H2 Hollandia, Solarcarport Biddinghuizen (Lowlands), Zonnewarmtepark Dorkwerd, and the Bontepolder project. Some of which feature innovative technologies such as green hydrogen and battery storage.

This is one of the hottest topics in the Netherlands, and the webinar conversation was kicked off by reflecting on the state of the market, which is emphasised by articles such as NOS’ headline “Grid operators: stop solar parks where there is hardly any demand for electricity”. Following is a summary of points made by both speakers and answers to some questions from the audience.

Discussion between panelists


What legislative/regulatory changes do you think are needed to solve/mitigate some of the existing barriers?

  • We need new forms of contracts, and focus on permits first. Work on aligning the bidding and awarding processes. Where tenders are awarded more carefully also on the basis of location strategy.
  • Apply congestion management. What is the best way to roll this out properly? When is the grid full?
  • Apply cable pooling: current legislation only allows solar and wind to be used jointly. There are ongoing proposals for this.

How do you view making PV systems mandatory on large roofs or large parking lots, as widely reported in the news just last week? Is this desirable, conducive and feasible?

  • We shouldn’t just fill up roofs with solar, there has to be a more integral planning behind this. For example, focusing on small industrial sites that have a higher energy demand.

How big a role do you think storage will play in minimizing grid congestion?

  • Storage will be indispensable in making the energy system more flexible. The challenge is to use it as efficiently as possible and we are currently in a trial and error phase - we are learning as we go. We shouldn’t be afraid to innovate as we apply and adapt to regulations as these evolve.
  • It is okay to not have it all figured out. However, not forgetting that if we apply it, we should not exacerbate the problem.
  • Grid operators are talking to market participants on the topic of storage, there is a lot happening in the market with concrete business cases for storage going forward to the operational phase. One example of a business case for batteries is including cable pooling where you can finance these as separate entities side by side.

What are some tools that you are looking into to solve the current bottlenecks in the grid?

  • Two potential ways to have a smarter and better fit of renewables. 1) Smarter locations. We need to plan solar locations smarter. Solar energy follows existing new grid capacity, not the other way around. There currently are limited legal means in place, so we suggest to appeal to the municipality not to license solar projects that do not comply. 2) Smart grid capacity. Smart contract forms and maximum size of the grid connection at 50% of the total peak capacity of the generation installation. The appeal; solar generation can continue to grow, but requires consideration of smart contracting, planning and integration.

Q&A with the audience


Enexis speaks out about the development of solar initiatives. If you look at the scarcity map you might say: that's richly late.

Gertjan: That is true, but that does not alter the fact that we must look at how we are going to do it in the next five to ten years. Generation has grown tremendously fast but the naturalness of recent years is no longer there. This forces us to take a much more critical look at how we are going to do it. Namely, by fitting in smarter.

Grid operators started too late with grid extensions, and it now feels as though the solar sector has to solve these problems. How to move forward?

Gertjan: We can see that there has been too little investment, because there is scarcity. Of course, we can also turn the question around: How would our environment have reacted if we had wanted to expand by 2GW per year four years ago without knowing the concrete applications for this. That would not have been accepted either. We are now expanding to the maximum in order to increase grid capacity, but we have also learned something else over the past few years: don't just focus on more grid capacity, but also look at how to use those grids efficiently. We are working hard on the former. For the second, we need the help of market parties and policymakers.

How does Enexis view the development of Zon op Dak?

Gertjan: We see a great social need to use more rooftops for generation. Encouraging is becoming more and more of an obligation. But rooftop solar is also facing scarcity. And so it is important to pave the way for Sun on Roof. To some extent, it also has some advantages with existing users and existing grid nearby. But there again, we need to look for ways to minimize the impact of more and more solar on rooftop on the lower grid areas.

Regarding the scarcity map: will it remain so red, even if everyone does their best to use the grid ever more intelligently?

Gertjan: I fear that we will not be rid of it for the time being. All the more reason to adapt to it and make clear choices in those forms of generation that we as a society find add the most value.

To learn more about

the topic beyond this article,

join Solarplaza Summit The Netherlands on 27 May, taking place in Amsterdam.