I ordered the beginner's kit shown below from Edmund Scientific for approximately $40 with shipping.
As evident in the pictures above, the kit is comprised of 8 small solar modules (also called cells or panels), a small motor, a tiny fan and stand, and a couple plastic wrenches to fasten nuts.
The first step necessary is to determine the apparatus you wish to power. The kit provides you with a small motor that you can attach a small fan to via the spindle attached to the motor. However, using this particular kit, you can also power a variety of other small apparatuses such as a light bulb, clock, calculator, etc.
The second step in the process is to determine the load voltage and load current of the apparatus you wish to power. Once you have done so, you will need to arrange the small solar cells to form a circuit that will provide you with the necessary voltage and current (amperage) needed to power the apparatus.
Each solar cell has a positive side and a negative side and produces an output of approximately 0.4V and 100mA. To increase the voltage, connect the cells in series (negative point connects to positive point). If you connect two cells in this manner, your voltage will be 0.8V, but your amperage will remain at 100mA. To increase the amperage, connect the cells in parallel (negative point connects to negative point and positive point connects to positive point). If you connect two cells in this manner, your amperage will be 200mA, but your voltage will be 0.4V. To increase both simultaneously, you must use multiple cells and a variety of series and parallel circuits.
In order to power the motor and spin the fan that comes in the kit, the output of the solar system required is 1.6V 200mA. As you can see in the picture below, I have arranged the cells using a variety of series and parallels to achieve the necessary output.
The clarity of the picture makes the positive and negative posts difficult to see, but I have used 4 parallels to increase the current to 200mA and tied the parallels together using 3 series to increase the voltage to 1.2V. I then use the two wires from the motor and connect one to a positive post and the other to a negative post to create a 4th series and increase the voltage to 1.6V, completing the entire system.
As the video below shows, upon placing the entire solar system into the sun, you see the light from the sun power the attached motor in turn spinning the fan. Though the video shows the fan appearing to sputter, the fan is in actuality continuing to rotate while the panels are in the light of the sun. Once I block the sun from reaching the panels, the fan stops spinning.
The next step would be to send the energy to a battery to store it and be able to use the energy even when the light is not directly contacting the solar panels. I need to research how I would go about storing the energy and hope to demonstrate the process in a future blog post.
