Sonnenwagen News

4 challenges to overcome when building a solar car

Find out more about the challenges that can arise when building a solar car in your own workshop.

Imagine it’s a rainy Sunday afternoon and you find yourself bored in your workshop, thinking about your next project. What could you do next? What about building a solar car yourself – a sustainable and aesthetically appealing masterpiece that runs purely on solar energy? Your neighbours would surely be jealous… Unfortunately, it’s not that easy. In addition to math and engineering skills – and let’s be honest, most of us are already failing miserably here – there are several other challenges that must be mastered to build and drive a solar car. So, here are four challenges our Team Sonnenwagen had to master to successfully participate in the World Solar Challenge (WSC), last year. Take notes everyone!

1. The Laws

Our Team Sonnenwagen had received a road approval for the period of the last WSC and the testing phase before, since the Sonnenwagen met most of the legal requirements regarding safety and functionality. For example, instead of rear-view mirrors – which cause too much air resistance – the Sonnenwagen had a rear-view camera in order to see what happens behind them.

Fun fact: For Germany the solar car was 3 centimetres too long and did not receive a road approval. No, this is not a joke – we are in Germany after all and have to stick to the rules.


So, before you start construction of your new dream solar car, think about how long you want it to be – because you see, size does matter sometimes. Of course, it should also come with turn signals, a seat belt and a rear-view camera like the Sonnenwagen.

The truth may be harsh, but building a solar car is expensive. So, you can either take your savings out from under your pillow or try winning the lottery to get the money for your endeavour. Or you can do it like Team Sonnenwagen instead and present your project at trade shows and research days to find sponsors who will support you. According to team Sonnenwagen, it is pretty hard work to convince people that you can build a car only powered by the sun, but in the end it’s worth the effort.

3. Weather and Climate

Thanks to long sunny periods in Australia the conditions are ideal for a solar race. But what if you want to drive your solar car in less sunny regions – like pretty much the rest of the world? 

Here you can also learn from Team Sonnenwagen: The structure of the solar cells ensures that the Sonnenwagen can also drive in diffused light, which is the case when it rains, or the sky is overcast. However, the car then drives much slower, i.e. 20 km/h instead of 100 km/h. In combination with the battery, the racing car then comes back to 50-60 km/h. So, no driving on German Autobahn in this case.

This means for you: Make sure you use the right solar panels and batteries, then you can shine even in the rain!

4. Driving Skills

According to Team Sonnenwagen, driving a solar car is completely different from driving a normal car. The gas pedal is operated at the steering wheel, the brake with your foot (please do not confuse this order).

Inside, the Sonnenwagen does not have a proper seat because every gram count. If you plan to take your solar car out for a spin around town, keep in mind to prepare for an uncomfortable ride. In addition, it can get rather hot in the Australian midday sun and the lack of insulation – here again, every gram count – results in a lot of noise in the car. So, no listening to music while on the road.

And now comes another important tip from our team members: Go on a diet before you get into a solar car. Because every single piece of chocolate and every potato chip from the last few months has its effect in the tight car. Once again: Every gram count…

Now you know what to expect if you want to build and drive a solar car: Think of the laws, the costs, the weather, your driving skills and your diet. But it’s probably best you start with math and engineering lectures first…

Latest news