Thijs Jonkman
During his internship Thijs built several experimental setups needed for performing experiments in the field of alkaline electrolysis. In addition he laid the groundwork for the alkaline electrolysis high pressure testing facility.

Key Questions:

  1. How did you hear about ZEF and the project you worked on?

I first heard about ZEF during a presentation held by Jan van Kranendonk at the Haagse Hogeschool on the TU Delft campus. The minor Sustainable Energy Technology I was following at the time suited ZEF’s profile.

  1. Do you feel that your time at ZEF has contributed to your studies and to your work experience? In what ways?

Yes, it definitely has. The workload was very diverse and because of that I learned a lot in a short amount of time. It also motivated me to have a positive view towards working in the near future (especially in the sustainability sector).

  1. What was the social atmosphere at ZEF like? Do any social activities take place during the project?

During my time at ZEF I was almost always in close contact with multiple people from various places in the world. This made interaction easy and efficient. Every Friday we got together in the main office for some drinks, snacks and to blow off some steam.

  1. Do you feel that you got to express your ideas, experience, skills, and creativity during your time at ZEF?

Yes, more than I thought beforehand actually. The short, daily meetings helped in this aspect.

  1. Do you feel that you were trusted to work independently on your tasks and that you were given enough responsibilities?

Yes. When you start off with the project that has been set, you begin checking off small tasks. Once you delve more deeply into the project and have proven to be able to work independently and successfully the amount of freedom increases. You can then inform about your progress in a more concise way.

  1. Was your time at ZEF what you imagined and hoped it would be?

It was better than expected. Especially the amount of independency and responsibilities I enjoyed a lot.

  1. What did you think about ZEF, and the overall idea/venture of the company?

I’ve thought about it as a very ambitious project with a lot of potential still needing to be fulfilled. That being said, I believe in the idea that ZEF embodies and the road they are taking to achieve it.

  1. What are you up to nowadays?

I’m currently doing my graduation thesis at a design and build organization of high-end composite structures called KVE Composites.

Join us!

We have projects for all backgrounds and levels (MBO, HBO, WO). Take the first step and receive personal consultation about projects that fit your background and interests.


Initial contact

Every internship is different and each educational institution requires a different approach. That’s why we start with an assesment of your background to see if there could be a match. It starts with sending us some info (like your CV, starting periode, etc).



After the initial assessment of the info you sent we start with the actual application stage where we plan interviews. In these interviews we discuss your application and give you additional info about ZEF and some specific assignments. If the meetings are positive we can go to the final stage.



If it’s a match it’s time to arrange all the formalities. In this stage we make sure that you have a project description which is approved by your educational institution and we make sure that everything is ready so that you have a great start at ZEF!