Inside a solar cell you have two wafer-thin layers of silicon crystal, placed on top of each other to make a sort of silicon sandwich. The top layer has been specially treated so that its atoms are unstable and, they have one too many electrons that they would really like to get rid of. The bottom layer has also been treated, but this time the atoms have a few empty spaces that could really do with an electron to fill them. So the top layer is desperate to lose a few electrons, the bottom layer is desperate to gain a few electrons, and the electrons themselves are itching to move from the top layer to the bottom. This setup puts everything in place for electricity to be produced once the solar panel is exposed to light.

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There is one last piece to the puzzle before the electricity can be used. The electricity generated by PV solar cells is DC (direct current). The electricity used in your house is AC (alternating current). So the current from the solar panel system has to go through an inverter, to convert it from DC to AC before it can be pumped into your house and used to run appliances.