Top Dutch Solar Racing: racing with the cars of the future

Groningen, Netherlands

Top Dutch Solar Racing & SABA

The Green Spirit of the Solar Racing team from Groningen in the Netherlands during the Solar Challenge Morocco showed what a solar energy-powered car can do. SABA is proud of making a contribution to this. Top Dutch Solar Racing is a multidisciplinary solar racing team from Groningen and consists of motivated students from different educational institutes and levels. The team participated in the Solar Challenge Morocco with their car, Green Spirit. This is a five-day race for solar cars competing against each other in the Moroccan desert. Green Spirit’s flexible solar panels are bonded with Sabatack® Fast. “The cells are still as solidly attached as they were before the race,” says Timo Kuizenga, electrical engineer on the solar racing team. Thanks to the solar cells’ successful bond to the solar car, the team had one less thing to worry about and it gives SABA yet another proven application!

An excellent result

In October 2021, the Top Dutch Solar Racing team finished in fourth place in the Solar Challenge Morocco. The team feels that it could have placed even higher, but due to delays in building the car, too few test kilometers were driven. If there had been more time for testing, this might have prevented the brakes from seizing during the first two days of the race. Yet, the team has learned a great deal from this. As it did from the process as a whole; from designing the car up to and including the race itself, which was a tremendous learning experience for the students. They created a beautiful end-product: Green Spirit. Green Spirit’s solar roof was designed not a millimeter too large and as result provided an excellent balance between weight and the required generated energy yield. The car consists of bonded multi-materials. Adhesives were also used to attach the solar cells to the car.

Top Dutch Solar Racing team
Right choice for attaching the solar modules

Right choice for attaching the solar modules

The previous Top Dutch Solar Racing team in 2019 applied the solar cells to its car using double-sided film. Film immediately bonds, which means that the alignment must be perfect the first time around and that there is no room for small errors. This meant that the new team was not able to make use of this technology. This was because the Green Spirit’s solar modules cover the entire width of the car in order to be able to efficiently make use of the car’s entire surface. In this situation films could cause bubbles as a result of which the ends of the modules could come loose from the deck during folding. As a result the chance of a faulty alignment would have been very high. This is why the team opted for a flexible bond using Sabatack® Fast.

The Sabatack® Fast choice

The most important reason for choosing Sabatack® Fast was related to the flexibility of positioning the solar cells during placement. The adhesive gives you the time to perfectly position the modules after putting them down as straight as possible by eye. Another reason for choosing Sabatack® Fast is that it provides a boosted and flexible bond. This ensures that vibrations during driving are absorbed and are not directly transmitted to the cells. Micro cracks in the solar cells were a problem encountered by many teams. Micro cracks reduce the yield of the solar cells, something you naturally want to avoid! Another benefit of Sabatack® Fast is that it is able to withstand extreme changes in temperature, such as those occurring in Morocco. While standing still, the temperature of the solar cells rose to some 40 to 60 degrees. During the night, the temperature in Morocco went down to as low as 9 degrees. The flexible bond was able to effectively withstand these extremes. The cells are still as solidly attached as they were before the race.

Sabatack® Fast
The future of solar cars and adhesives

The future of solar cars and adhesives

What is going to be the role of adhesives in building these future-proof cars? Bolts and melting are not an option according to the racing team’s electrical engineer. “Bolts are aerodynamically disadvantageous and furthermore you do not really want to drill holes into the solar modules or melt down the cells.” Making use of adhesives for bonding is very important in the solar car sector when flexible modules are used. Double-sided foil is another conceivable method, but this does not work for large modules, such as the modules used by the Top Dutch Solar Racing team. By contrast adhesives work well in this case. There are not very many other methods to properly attach these solar modules. The question now is, can the flexible bonding make a further contribution when you extend its use to all other means of transportation? The expectation is that due to the use of new materials, bonding will become increasingly more important. The benefits are legion and the possibilities are increasing day by day. Improved batteries are a given and this area is presently undergoing a great deal of development. Solar cars contain batteries and thus provide for an interaction between two technologies. The same things applies to hydrogen. You could also add a solar deck to a hydrogen-fueled car to extend its range by further charging the battery when your car is standing in the driveway. The efficiency of solar panels is expected to continue to increase, which in turn creates the expectation that the relevance of adhesives will also continue to increase.

"The world of adhesives opened up for us during the project. I believe that flexible bonding was the perfect solution for the problem we had. The available repositioning time, its weather resistance and flexibility are three Sabatack® Fast properties that were very important for us. The adhesive proved itself during the race and I will be sure to recommend it to the next team." Timo Kuizenga Electrical engineer
Timo Kuizenga