I think you could bear another watch yourself, and a little less negativity.

The rear side panels are hinged on top, so they can be raised to the sun while the tuk is stationary. As well, in the back, on the roof is clearly another panel.

You can see the lack of translucency at about 0:07, and his hand on the rear frame at 1:14. Actually you can see it a bit better at 0:04.

Further, its entirely possible that he has an extra vehicular set of panels at home base. He probably parks it with the doors open, facing the rising sun, catching some charge before the horizontal panels become directly illuminated.