Many Solar Energy companies explain that the Inverter is the brains of your home Solar Power System. They call the Inverter the brain because it is a device filled with chips and diodes and other assorted electronic doodads like your computer is. If we want to equate the parts of a Solar Power System with body parts, the Inverter is closer to the Digestive tract. It takes the energy that the Solar Panels take in and converts it to a form of energy that your home can use.
DC Power From the Panels, AC Power for the House
Solar Panels produce Direct Current electricity. This is electrical current that flows in one direction, form Positive to Negative, just like it does with the batteries in an electric torch. However, the appliances in your home are designed to operate on Alternating Current.
Alternating current is the power that normally comes from a generator. The current changes direction rapidly. A frequency of 50 Hz means that the current changes from positive to negative and back 50 times a second. The electronic parts in the Inverter switches the current at the rate of 50 times a second, converting it from DC to AC.
Micro Inverters, Small and Efficient
Older Solar Power installations used String Inverter technology. With a String Inverter, the DC power from all of the panels in the system is fed into a single Inverter where it is converted from DC to AC. This was efficient because there was only one inverter to worry about. If the system is connected to the grid, it is a simple matter to synchronise the frequency of the inverter with the frequency of the grid.
Unfortunately, if one panel in the system is operating at less than peak efficiency, perhaps it is shaded or covered with leaves, the output of the entire system drops to the level of the lowest performing panel. Worse, if the inverter goes on the blink the whole system is down.
A newer technology is called Micro Inverters. In the Micro Inverter set up each panel has its own small inverter. The circuitry of the micro inverters takes care of synchronisation. Now, is a single panel has a drop in performance, the system output is the average of the outputs of each panel, rather than dropping to the lowest performing panel.