Yes, looking to the picture it seams that in top of the bonnet there are some solar photocells. So I've found the following information in reference to a solar-eletric version of the ATW Lissy:
"The standard equipment factory gasoline engine was replaced with a 4.7 kW DC electric motor and the batteries with tubesheet 48 volt, 110 Ah. The top speed was 55 km / h indicated. The range depending on driving style with 50 to 70 km The 80 or 160 watt solar cell loaded the batteries."