In a DC system, the energy goes through the solar panels, battery and to the inverter with DC power, and the inverter converts the power to AC power so it can be used by your home appliances.
Advantages of DC Coupling
- High efficiency for battery charging. The charging of the battery has a roughly 99% efficiency with this system.
- low cost set-up.
- efficient running.
Disadvantages of DC Coupling
- complext to set up.
- more expensive for systems above 5kW.
- ower efficiency when powering large AC loads due to the DC-DC-AC convertor.
In an AC system, the solar inverter is coupled to a multi-mode inverter to charge the battery.
The power goes through the solar panels with DC power to the inverter where it is converted to AC power. It then goes through the switchboard, the multimode inverter using AC power where it is then converted to DC power and goes to the battery, then back to the multimode inverter where it travels to the switchboard, is converted back to AC power and then it is consumed by the home appliances.
While this may seem more complicated, this is actually quite a lot simpler to set up.
Advantages of AC Power
- higher efficiency when used to power AC appliances during the day (for example, the air conditioner).
- lower installation costs for larger systems (above 3kW).
Disadvantages of DC Power
- lower efficiency when charging the battery system (roughly 5-7% loss in efficiency).
- solar inverters can be very expensive.