The bike

The idea to use a solar bike isn’t new by any means. We couldn’t figure out when the first ones were build but there has been the suntrip since 2010 which is a race for solar powerd bikes form France to China. Luckily for us, there are many designs to draw inspiration from.

Our setup

Specs:

• 4x111W solar panels
• 14x98Wh batteries
• 1200 W gearless hubmotor
• beltdrive
• gearbox
• 2500 Wh per day without clouds
• 900 Wh per day when cloudy
• 64 kg (39 kg trailer, 25 kg bike)

We decided to use the combination of a belt, gearbox and rear hubmotor to build a very robust system. Thanks to the gearless hubmotor we can use regenerative breaking which increases the range by 10-20 percent depending on terrain. We bought a trailer and build the supporting structure for the panels out of aluminum pipes.

The panels can be easily clipped on the rack. This allows us to remove the panels when accessing the storage area below as well as tilting them to harvest more sun in the morning hours while sleeping. This is especially important when the sun is low, as the angle of the panels can easily double the output. During the day when the sun is up, tilting is not too important as a small change in angle of the sun doesn’t change the power output significantly. Put in other words, sinus is not linear (I know this might be a surpise to many physicists).

For a more detailed description have a look at our blog post.