All solar electric systems work using the photovoltaic effect.

When exposed to sunlight, a solar panel (module) produces direct current electric flow. (Thanks to a French physicist, who discovered the photovoltaic effect by accident in 1839 while experimenting with electrolytes). When photons, contained in the sun’s rays, hit the solar cell, they knock electrons out of their positions, which opens up an opportunity for other electrons to enter. This cycle continues to repeat, creating a flow of electrons in one direction, which is actual direct current electricity (DC).

But this type of electricity is not usable in our conventional electric appliances, so it has to be converted into conventional AC (alternating current) electricity. We can do so by using devices called “inverters,” which convert DC electricity into AC electricity. Inverters are located between solar modules and a point of interconnection with the house’s distribution panel. Every photovoltaic system employs an inverter.

Just like in any other electric circuit, components of a solar electric system are connected with electric wiring.

After it is converted to AC, it either goes to the building appliances being used, or it is pushed back into the grid spinning electric meters backwards. In this case grid used as a power storage facility, so when you need electricity in the night time, you draw it back from the grid, spinning meter normally.

Photovoltaic systems are also used in applications where an electrical grid is not available. These systems are called off-grid PV systems