Solution fo EV camper

DIY
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1

I consider using new E-Ducato as a platform for my new camper van.

If I want to have solar on the roof, what solution will be ideal?

I expect in the summer it could generate about 2 kWh a day, which is like few kilometers of driving. How to calculate expected energy wasted by aerodynamic drag of the PV panels?

In winter I expect about 0,5 kWh per day, which will be usually consumed by the onboard electronics the same day, so it will be probably better to not charge big 400V battery, but only the small 12V.

I can imagine the the ideal solution for winter will be PV panels connected in parallel, so there will not be big loss in MPTT. But in summer it will be better to have panels serially connected to high voltage, so MPTT will not need to make inefficient step-up conversion.

I can imagine having PV panels with switchable connection - 20V in winter or 400V in summer and two MPPTs because there is nothing supporting such big voltage range.

Does it make sence or this overengineered solution will weight so much so potential energy saving will be less than energy wasted on drivetrain power consumption?

Do you know about some existing projects what are effective?

2

This is a false assumption. MPPT’s operate best with a high voltage input, so modules should always be wired in series. Switching configuration between seasons is not necessary.

The 400V EV battery usually cannot be dc charged directly from PV modules, as it needs a CAN interface to turn on and control the battery. In summer if you have spare energy from the solar install, it is best to use an AC charger to charge the EV battery via an inverter.