Grid Tie Inverters (GTI) convert the direct current electricity generated by solar panels into grid-compatible alternating current. They are the heart of every solar power system. They can be used to power all the loads in a home and/or export the power onto the local utility grid. For the GTI to export power it must match the frequency of the local utility grid. The power factor component must perfectly line up it's output voltage, current and phase with that of the utility grid.

For safety reasons, grid dependant systems are not able to export power onto the local grid in case there is a local grid blackout. When the grid tie inverter detects a blackout or severe voltage drop that lasts for more than a few seconds, it will immediately shut itself down and cease to export power. If it were able to continue exporting power during a blackout, this condition would be known as 'islanding'. All grid tie inverters must incorporate an 'anti-islanding' feature which is designed to protect utility workers from serious injury if they happen to be working to resume power to a blacked out area of the grid.

If you require round the clock backup power during a blackout situation, then you'll need to incorporate a battery bank or generator to supply that power to your essential or critical loads in the home. Battery backup systems cannot be installed upstream of the generation meter (mG). With a battery bank or generator, this system now becomes what is called a grid interactive system.