It is merely GCSE, and I don't think you concentrate on logistics. Just the project and the concept should score fine. Personally I think that's quite good!
Obviously the teacher of the class couldn't appreciate the project! Even with a bad write up I would have given it an A-, its a wonderful (and fun) idea!
This was in the paper last month, it said something like he only got a c because it was just simpily connecting a turbine to the wheel and wiring it up to his phone.
it was a good idea though i think.