What is the difference between Grid Tied Inverter and Off Grid or regular inverter?

In Solar Power by Jhong Regalado,
posted 8 years ago and was modified 4 years ago

Basically, inverter converts the DC (Direct Current) power source into AC (Alternating Current). Grid Tie Inverters also known as GTI are inverters that you can connect directly to the power outlet. Yes, your house will have two diffrent power sources, and it will not explode. There's a microcontroller inside that synchonizes the generated power to the grid. You cannot do that in regular or Off Grid Inverters. If you will connect the Off Grid Inverter to the grid lines, the inverter will be DAMAGED and might cause injuriies and fire because it is not designed to sync the generated power to the grid. Hybrid Off Grid Inverters (HOG) also known as Grid Tie Inverters with battery backup are simply a combination of GTI and Off-Grid Inverters. Here's the differences between these 3 types of inverters


  Grid Tie 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 Setup

Grid Tie Setup

Off Grid Setup


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