The idea seemed brilliant on paper: install solar panels on the roof of an electric car to extend its range. After all, if the sun can power a house, why not a vehicle? Several enthusiasts and even some manufacturers have tried the experiment. The results, however, are far from meeting expectations.
The main problem is surface area. The roof of a car offers, at best, about 2 square meters of usable space for solar panels. At current efficiency levels, this translates to about 200 to 300 watts of power under optimal conditions (direct sunlight, no clouds, ideal angle).
In practice, this means that a full day of sunshine would add about 3 to 5 kilometers of range. For a vehicle that typically consumes between 15 and 20 kWh per 100 kilometers, the contribution of solar panels remains anecdotal.
Several manufacturers have explored this path. Hyundai offered a solar roof option on the Sonata Hybrid, and Lightyear attempted to build a car entirely designed around solar charging. But even Lightyear, with its ultra-efficient panels and aerodynamic design, could only promise about 70 km of solar range per day under ideal conditions.
The additional cost of the panels, their weight, and the complexity of integration make this solution hard to justify economically. For now, the consensus among engineers is clear: it’s better to invest in larger batteries and more efficient charging infrastructure than to try to turn cars into mobile solar panels.

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