The inverter is the 2nd most important component of your system, after the solar panels themselves.
They convert the electricity generated by your panels:
Inverters are used to transform the DC electricity produced by your solar energy system into the alternating current (AC) electricity commonly used in most homes and business for virtually everything that uses electricity (lighting, appliances, electronics, etc.).
An inverter takes the electricity from the solar modules and synchronizes it with the utility AC electricity so that your electricity is of the exact same quality as the utility. This also allows you to sell electricity back to the grid, since your electricity is made compatible with the grid by the inverter.
Most inverters are made to work with the standard grid-tied system without batteries:
But there are also some inverters available to work with battery back systems. These dual use inverters (the bottom image on the right) often include a battery charger, which automatically maintains the charging status of your batteries so there are always ready for a blackout or emergency situation.