Not every solar bike needs panels on the bike. Andreas Lemmer from Portugal went the other way and built a tiny off-grid charging station just for his e-bike. The bike is a normal city pedelec. The “fuel station” is two small solar modules on a stand, and that is all it takes.
The design is pleasingly simple. Two 60 W / 24 V nominal panels are wired in parallel for 120 W in total. At their typical maximum power point of around 34 V they are a perfect match for a 7S or 8S lithium-ion pack (24.9 V or 28.8 V nominal, charge limit 32.8 V for 8S). A balancer and a voltage end-point limit protect the cells.
With a 15 Ah battery, a full charge takes about half a day of sunshine. Andreas recommends a panel size of 50–150 W for this kind of setup: smaller is too slow, and bigger brings little benefit for a single e-bike pack.
Why we love it: this is the most accessible kind of solar mobility. No custom frame, no fragile panels bouncing on the road, nothing fancy. Two standard panels and a suitable charger turn almost any e-bike into a vehicle that runs on sunshine. Andreas documented the setup and released the photo into the public domain so others can copy it.
Technical data
| Builder | Andreas Lemmer, Portugal |
|---|---|
| Bike | Standard city pedelec (e-bike) |
| Solar | 120 W stationary: 2 × 60 W panels (24 V nominal) in parallel, MPP ~34 V |
| Battery | Lithium-ion 15 Ah, 7S (24.9 V) or 8S (28.8 V), ≈ 375–430 Wh |
| Charge control | Li-ion balancer + voltage end-point limit (32.8 V for 8S) |
| Solar charging time | About ½ day of sunshine for a full charge |
| Recommended panels | 50–150 W |