The usual solar e-bike conversion keeps charging at home and rides on a pre-filled battery. Kilian Weigand went the other way and put the power station on the bike itself: a large rigid panel sits over the front cargo compartment of a red Bullitt frame labeled PEPPER, feeding an MPT-7210A MPPT controller in the front bag and a battery pack that runs a Bafang BBS02 drive. The setup produces around 900Wh per day, a solid figure for a bike carrying its own power plant.
Putting it together took several months. The support bracket was redesigned in Autodesk Fusion 360 and 3D-printed in orange filament on an Alfawise Cartesian printer, with the nozzle around 220 degrees Celsius. The printed clamp attaches the panel support to the front structure using metal hose clamps and bracing wires, heavy-duty double-sided mounting tape goes under the panel, and the panel itself is fixed at six screw points, with yellow brackets at its front corners.
Some details stand out. The first road test cracked the black printed clamp, so a stouter bracket was designed, and the following 60 km ride finished with no bracket failures. That ride included a thirty-minute stationary charging stop, and the panel covered the majority of the trip's energy consumption. Readings along the way showed roughly 114W of solar generation at 2.32A, with about 37.5V input against 49.2V battery voltage, while the motor draws up to around 200W under pedal assist.
One open point: in stormy conditions the panel has to be turned flat to the road, a handling trade-off worth watching. A second fold-out panel and an automated two-axis sun tracker using light sensors are still on the plan, and this year's SunTrip Solarbike Adventure race will be the real test of the concept.
Project by Kilian Weigand. Watch it on their YouTube channel: