The solar car is like an electric car Eldorado. There, all wishes will be granted: we will charge our cars for free every day. No more links to electricity and oil forever.
But we are as far away from that as we are from having an Eldorado in our lives. Various companies have started experimenting with solar-powered cars and are even selling their own models.
Toyota, which developed the Prius, filled the roof of the Prius so that its panels could support the car’s electrical components. Mercedes tried the same idea with its Vision EQXX. However, from Stuttgart to Silverstone, a distance of more than 1 200 kilometres, they barely managed to increase the car’s range by less than 50 kilometres.
However, the commercialisation of the solar car is still a long way off. In the Prius, its contribution was (very) small. The Mersedes is a prototype designed to push the boundaries of efficiency in terms of aerodynamics, battery chemistry and engine consumption, so it is not very representative either. The 3.57 kWh of energy recovered by the solar panels in such a vehicle was much more than in a road car.
Sono Sion, one of the most advanced projects, was eventually cancelled. The people behind the Lightyear project, who claimed to be able to drive 70 km a day for free with their solar car, also eventually ceased operations. In fact, since the announcement of the vehicle in 2019, those responsible for it have not stopped lowering their expectations, and with it the number of kilometres that the car could cover per year thanks to its solar panels.
However, this has not stopped the owner of a Tesla Model Y from claiming on Reddit that he has turned his electric SUV into a much more efficient vehicle thanks to the solar panels along the roof.
Figures which, of course, need to be taken in moderation.
Quarantine
According to a Reddit thread, this Tesla Model Y owner claims to have developed a foldable solar panel system that allows him to charge between 30 and 100 km per day.
When presenting his project, the user explains that the panels are folded and mounted on the roof rack. He says that in this first version, the panels protrude about 27 cm from the roof of the car, but in the new version he is working on, he will be able to reduce the height to about 15 cm, improve the folding, and create a carbon-fibre support to facilitate the assembly.
In total, according to the user, the future Tesla Model Y will be able to carry 4,000 W packed into the roof, which means that once it is installed, it will be possible to recover some of the sun’s energy, convert it into electricity and charge the car while it is parked.
However, there are many doubts here. Firstly, he assures us that he is working on transforming the sun’s energy into electricity and directly into the car’s battery, so we understand that, for the time being, the energy is being stored in the battery, which then charges the car.
The other big question that we have is about the actual efficiency of the system. In 2019, Toyota developed a prototype Prius that filled the entire roof, rear window and bonnet of the car with solar cells. With these, Toyota claimed to be able to drive an extra 45 kilometres, but it relied on the Japanese type-approval cycle, which is much looser than the European one.
In the case of the Tesla Model Y, the weight of the panels is close to the maximum weight of 75 kg that can be carried on the roof in the United States, which will inevitably have an impact on fuel consumption. First of all, the 75 kg weight is more or less equivalent to carrying an extra person in the car. And, more importantly, the impact on the aerodynamics of the car, which would suffer greatly. The developer says that he has not calculated the latter, but believes that fuel consumption would be 10% lower.
All this has led some reviewers to suggest that the car will only be able to travel just over 40 kilometres in real driving conditions. Not to mention the impact of solar towing on vehicle dynamics and ride comfort, as it must be difficult to ignore noise.
