What's the Difference between on Grid inverter and Off Grid inverter?
Basically, inverter converts the DC (Direct Current) power source into AC (Alternating Current). On Grid or Grid Tie inverters are inverters that you can connect directly to the power outlet or Grid. Yes, your house will have two different power sources, and it will not explode. There's a micro-controller inside that synchronizes the generated power to the utility Grid. You cannot do that in regular inverter or Off Grid inverters. If you will connect the Off Grid inverter to the Grid lines, the inverter will be DAMAGED and might cause injuries and fire because it is not designed to sync the generated power to the Grid. Hybrid Off Grid Inverters also known as Grid Tie Inverters with battery backup are simply a combination of On Grid inverter and Off-Grid inverters but with MPPT solar charge controller to charge batteries. Here's the differences between these 3 types of inverters:
On Grid or Grid Tied inverter | Off Grid inverter | Hybrid On Grid inverter | |
---|---|---|---|
AC In | Yes | None | Yes* |
AC Out | None | Yes | Yes* |
Grid power is required for grid synchronization | Yes | No | Yes |
Shuts down when the grid is down | Yes | No | No** |
Anti-Islanding Protection | Yes | No | Yes |
Energizes loads during grid failure (black out) | No | Yes | No |
Connected directly to the power outlet | Yes | No | Yes (AC In or AC Terminal) |
Feeds all generated power to the grid line | Yes | No | No (Feeds surplus power only) |
Local electric company buys excess or surplus power | Yes | No | Yes |
Overload Protection | No | Yes | Yes** |
Inverter Cost | High | Low | Very High |
Full Setup Cost | Low | Very High | High |
Grid Billing | Yes | None | Yes |
* Connect the AC In or AC Terminal to the power outlet or grid line while AC Out on your appliances
** Critical loads only
Hybrid On Grid solar system Diagram:
On Grid or Grid Tie Solar PV system:
Off Grid Solar PV system: