Solar inverters are one of the most important parts of a residential solar energy system. Solar power inverters take the direct current (DC) that the solar panel makes and converts it to alternating current (AC) that is delivered to the home. Direct current (DC) is is the same type of current produced by a battery and Alternating current (AC) is usually produced by a generator.
And of course the Big question is why convert the direct current electricity to alternating current electricity? Well the main reason is that all the appliances in our homes are designed to use alternating current. The reason for that is that most of our electricity is delivered to our homes via long distance power lines and AC can be transmitted over long distances much cheaper than DC.
And the reason for that is that alternating current can be easily transformed to higher and lower voltage levels which is harder to do with direct current. So since alternating current can be transformed to a much higher voltage and then transmitted over hundreds of miles of transmission wires it is more efficient. Once the alternating current gets to where it is needed, like your home, it is transformed to a much lower voltage you can use in your home.
There are three types of solar inverters:
Stand-alone inverters - used in off grid stand-a-lone systems. The inverter in these systems gets direct current (DC)from a battery that is charged by solar panels to alternating current (AC) for powering appliances and other loads.
Grid tie inverters - used for systems on the grid where the the system feeds electricity to the grid to cause your electric meter turn backwards. This type of solar power inverter is designed to sync up or match the phase of the grid supplied sine wave. Grid tie inverters are also designed to shut down during a power failure to protect utility workers who may be working on the power lines during a utility outage.
Battery backup inverters - used for systems on the grid. The inverter converts direct current (DC) from a battery that is charged by the solar panels, keeps the battery charged while sending excess electricity to the grid. If there is a power outage the inverter can supply certain loads to the home.