solar cell sail

an electric motorboat could extend a sail made of flexible solar cells 

not for sailing, but for charging the batteries of the electric motorboat 

that would increase surface area of solar cells 

the flexible solar cells would be rolled up like a normal sail 

and extended upwards like a normal sail 

but current technology of flexible solar cells would be too fragile for sailing purposes 

and not flexible enough for sailing purposes 

the flexible solar cell sail could enable the electric motorboat to charge quickly 

and the flexible solar cell sail could be sold as an accessory 

for customers that are willing to pay to extend the range of their electric motorboat 

flexible solar cell sails could be relevant for electric cargo ships that need to extend their range