Newsletter 5: Towards the design presentation

27 - 03 - 2015

Solar Team Eindhoven Newsletter #5






No decision in a project like ours is easy. There are always multiple aspects that have to be taken into account. For a PR manager this means, are we able to tell you about our new car or are we not? This dilemma is getting smaller each week towards the World Solar Challenge. Especially now our Design Presentation is on the program. We are eager to tell all our sponsors, family and friends about the design of our new solar-powerd car. Although it is very hard for me, I do not want to spoil the surprise of our design yet.

This means that we are trying to give you information that shows you a tip of the iceberg, but the iceberg itself stays hidden.


With this project, we carry an interesting story. Our story inspires both young and old. This month, it were two children programs, Willem Wever and Klokhuis, who shot footage for a new episode of kid’s science!


We were invited to the second BZW Lenteprikkel. During this enterpreneurs gathering, Stella was positioned on the football field of the Rat Verlegh stadium. Our formal prime minister Jan Peter Balkenende had the honor to ride with us.





Over the last few months, the entire team has put a lot of effort into the design of the car. After the aerodynamics team delivered the final shape of the car, the structural engineers took over. Now that all strength calculations for the monocoque have been finished, it is finally time to start with the production.
Mathijs Brands, Michael Struik, Dennis van Iersel and I, are producing the body of our car at Weimo High Quality Composites in Aalsmeer. The production process for the used material, carbon fiber, is different from conventional materials such as aluminium. The entire process consists of a lot of manual work, which is a real switch after months of developing inside an office. It is very nice for us to see the influence of the decisions we made in an earlier stage. In this newsletter, I would like to give a brief introduction of this process.

The shape of the car is quite complex, so we have to divide the final body into multiple parts. Unprocessed carbon fiber consists out of flexible sheets, which can be handled easily. That is why we need to fabricate moulds to give the product the desired shape. These moulds are milled using a Computer Numerical Control machine, after which they are polished by hand. Then, each mould is treated with different chemicals to harden, clean and seal the surface. To make sure the carbon fiber does not stick to the mould and will come out of it, we apply a release agent. 
When the mould is finished, it is time to start laminating! Using an automated cutting machine, the required shape is cut exactly out of a carbon fiber roll. Then, the different layers are stacked together in the mould, according to the order determined by the strength calculations. During this step, it is key to work precisely and clean, since every mistake will be visible in the surface of the car. And we want a nice car, don’t we?
The final step in the production process is the curing of the carbon fibers, or more accurate, the resin in between the fibers. This is done in a vacuum bag to apply 

pressure, this makes sure the different layers are compressed, resulting in a perfect bond. The entire mould is then cured in an oven. Because of the heat, the epoxy resin in between the carbon fibers hardens. That final step converts the weak and compliant plies into one of the strongest and stiffest materials in the world.



Since we have to drive 3000 kilometers through the outback, we need energy and a lot of it! That is why we are very glad with the sun. Let me explain how we make sure that we get every drop of energy from to sun into our battery pack with our solar panels.

Our solar cells are made from monocrystalline silicon, almost the same material as the solar panels on your roof at home are made of. Each solar cell is encapsulated in a very lightweight plastic to create flexible panels, which can be fitted perfectly on the roof of our car.  This special plastic has very small pyramids on top, so even when the sun is almost at sunset the sunbeam is still directed on the solar cells.

A solar panel has one operating voltage at which the panel will give the most power; this point is called the Maximum Power Point (MPP).  However, this points changes during the day due different sun intensity. Therefore we use a Maximum Power Point Tracker (MPPT) to follow this point during the day. 

The solar panels in combination with these MPPT’s can harvest a lot of energy. For example during the World Solar Challenge in 2013 we reached a peak power of 1500 watt. At that moment the sun shines bright enough to power up to 3 washing machines! Or you can of course, use this energy to drive a solar car.


The Commisioner of the King visited the Automotive Teams at our University. He was visibly impressed about the capabilities of the automotive teams. Can we meet any higher visitors….?


Yes we can! We received an invitation to meet his and her Highness. Solar Team Eindhoven met the King and Queen of the Netherlands in Hamburg for a fast discussion on smart cities. We are excited to tell them about our current developments. More information about this visit in our newsletter next month.

Picture: Maurice Mikkers


As announced in the previous newsletter, we moved to our new headquarters. We now have an office, assembly room and storage all under one roof. In correction on our previous newsletter, our new address is ‘De Horsten 8, 5612 AX Eindhoven, University of Technology’.




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