2 April 2007
Question: What does "recommended generator power" refer to in the technical specifications of the inverter? Eg. Max DC input = 2700W, recommended generator power = 3000W.
A. (c/o RF Industries) Max DC input relates to the point where the inverter starts to back off for self preservation so if the array is really delivering over 2700W into the inputs of the inverter then the energy over 2700W is potentially lost, rather then converted.
In reality though if you install a Pv array at say 3KW peak a number of things happen.
1. For an appreciable part of most sunny days, particularly in the warmer months, the array will not be delivering 3000W, due to temperature derating.
2. After cable losses / breaker losses etc, a 3KW array will not be delivering 3000W into the inverter inputs.
3. For an appreciable part of the time, the array will not be delivering 3000W peak because the array will not be under optimal irradiance. Really what we are saying is you can put up to 3KW peak PV on this inverter and still expect to produce additional "worthwhile" useable output from the inverter.
Beyond 3KW and you start finding much of energy generated by the additional panels is just wasted.