Reverse Engineering: Building Solar Panels to Power Motors

We're trying to reverse-engineer the solar-powered toy car. We've dketched our designs and broken the build into discrete steps. Today we focused on building the solar panel that would power the motor.

Kai solders four 0.5V panels into one 2V panel.

The motor requires at least 1 volt of charge, But each cell maxes out at 0.5V. However, if you string cells together in series, you get a solar panel  where

Voltage = 0.5 * NumberofCells

Awesome! 

Our reverse engineers showed a monkish devotion to soldering.

The sunlight is less intense by the time we meet in the afternoon, so we decided to make our panels' voltage capacities twice as much as the motors' voltage requirements. At four 0.5V cells in series, the panel produces 2V. Three folks finished and successfully ran the motor off their panels! 

Ben solders tapping wire onto the back (+) side of a cell.

Here's a fun thing to think about. Why should a series wiring of the cells increase voltage (V), and parallel wiring increase current (Amps)? Why not the other way around?