In my last blog post I explained how to find an inverter’s real-world efficiency instead of relying on the inverter manufacturer’s numbers.
The CEC or European Efficiency numbers that I talked about are a much better number to use when comparing solar inverters. And for most people they will be all you need. However if you really want to understand how your solar system is going to perform then you should also look at the inverter’s “efficiency curve”.
Your inverter does not simply have one efficiency that it always operates at. The efficiency of your inverter will depend on two minor factors and one major factor.