Grid-Connected Roof Top Systems:
- The DC power from PV panel goes to a grid interactive (grid-tied) inverter which converts the PV panel DC power to 220 volt AC power that is compatible with the power grid.
- AC power from inverter is supplied to the household power needs.
- If the PV system is generating more power than the house can use, the excess is sent out over the grid to supply others. (Net Metering System)
- If the house needs more power than the PV system can supply, then the extra is drawn from the grid as usual.
- Grid tied systems only work when the grid is up. If the grid power goes out, the grid tie inverter is required to shut down immediately.
The factors that determine what size system you install are:
- What your current power usage is?
- How much money you have to spend on the system.
- How much space you have to install a system
- How much of your electric usage you want the grid-tie system to cover.
Benefits of Grid Connected Power Plants
- Lowest initial cost (no need for batteries and charge controller)
- Lowest ongoing maintenance cost or Recurring cost (no batteries to maintain and replace)
- Simplest to install
- Most efficient (because there are losses associated with charging batteries)
- Scalable you can start small and add