In a DC system, the energy comes from the solar panels and battery to the inverter in DC power without energy conversion. The inverter only converts the energy to AC power so it can be used by your home appliances or exported to the grid when there is excess energy that can be sold.
In an AC system, the solar inverter is coupled to a multi-mode inverter to charge the battery via AC wiring.
The power is generated by the solar panels as DC power, travels to the solar inverter where it is converted to AC power. It then goes through the switchboard to the multimode battery inverter using AC power where it is converted back to DC power and stored in the battery. Whe the home solar energy can no longer power the home, the multimode battery inverter converts the energy back to AC power to be consumed by the home appliances.
While this may seem more complicated, this is actually quite a lot simpler to set up.
Advantages of DC over AC Coupling
- higher efficiency in delivering power to the AC loads, fewer conversions required.
- Higher efficiency when charging the battery system (roughly 5-7% greater efficiency).
- lower installation costs for larger systems (above 5kW).
-Fewer components and lower risk of failure.
Disadvantages of DC over AC Coupling
- Mulitmode Solar Inverters are more costly but when considered as a whole, solar and battery DC coupled systems can be more cost effective.
- Often complex to set up.