Blog - Solar regulators

A solar powered ebike - possible?

I wish to make an ebike powered by solar panels in the wheel. What do you think about this?

It is a nice idea. We are always happy when our customers bring about some innovative ideas.

For the solar panels in the wheel (as suggested by the picture) we come to this calculation:

• Taking the size of the rim 26", the diameter is 66 cm, making the flat area of the wheel some 0.34m2.
• If you happen to fill this area with 60% by solar cells, you will get some 0.20m2 of solar panel flat space.
• The regular solar panel is 1m x 1.6m making some 1.6m2 of the flat area. Such panels have typically about 260Wp of solar power rating. With 0.20m2 of the wheel, you will get the solar power rating of some 32Wp.

It may seem the wheel is a big area, but after all you come to realize it is not so big. Also you need to face the issues of the solar panel shading by the rim holder.

For a solar bike powered with 36V 10AH battery, you need some 360Wh of energy to charge the battery. With a 32Wp panel you need some 11 to 12 hours of full sunshine to charge the battery.

In conclusion it seems, the wheel area is not big enough to provide for a sufficient solar charging for ebike.

Most solar powered bike projects use regular solar panels that are attached to the bike as a trailer. This way, the ordinary panels can be used directly. The trailer can also store some luggage for the trips. And when there is no sunshine, the trailer can be disconnected and parked making the bike free from the extra load.

What do you think now?