I would like to transform a tricycle into an electric tricycle and also attach a PV panel on a custom-made roof frame. When the tricycle is parked outside, the PV panel will continue to produce power. the battery will, at some point, become fully charged and thus won't be able to take up any more power (or well, it will but will then overcharge and become damaged). PV panels also can't be "turned off" as far as I know (a switch could be integrated but then the electric power would build up between the PV panel and switch, which could potentially damage the PV panel). The only solution I came up with is
* either pulling a blanket over the PV panel when parked
* or grounding the PV panel the second the battery is fully charged
I doubt either are used in commercial solar trikes ?
So how is this problem solved with other PV-panel equipped trikes/tandems/bikes/... ?
Another question I have is once I make the conversion, whether it is road legal in the EU, or whether I can use it, but only on bicycle lanes (while remaining under a certain speed -25km/h-) ? I found that with the electric motor on, it becomes an "L5e-A" or "L5e-B" vehicle under the UN-ECE (so probably road legal, but I think only if the vehicle, with the motor on, has had a vehicle inspection, which is probably time-consuming and expensive, so I would like to avoid that).
In regards to the PV panel: I'm thinking I might use not a full PV panel (60 cm x 120 cm) but rather a half-length PV panel above the tricycle (so 60 cm x 60 cm). Wouldn't that be enough ?
Batteries would be similar to what's sold commercially (meaning a 10, 13 or 17 Ah battery, 36V so having a capacity of 360 Wh, 468Wh, or 612Wh). With a 250W engine, that means 1,44 or 1,87 or 2,44 hours of riding). Speed would be well above 30 km/h (26 km/h up to 45 km/h motor speed support + pedalling ) so range is then at least 45 km to 75 km -this is a very rough calculation since engine inefficiencies (20-30%) aren't calculated in and speed ranges noted are also based on data for regular bicycles rather than (recumbent) tricycles-.