Calculating net yield from available data (e.g. Watchpower)

[berniej]

Hi Folks,

I have a newly installed system comprising a number of 230W panels, a combined solar controller/24V inverter charging batteries and supplying AC to some local loads.
It seems to be working fine but I'm struggling to find out how I can determine the net yield that I'm getting from solar (as opposed to line).

For example, if I'm running a 500W load I'd like to be able to see what %age is supplied from the solar/battery suply as opposed to the 240V line supply.
This will enable me to work out what I'm saving w.r.t. electricity bills.

I have an RS232 interface on the unit and have successfully connected to the Watchpower program - I am getting data through.

Is Watchpower capable of providing the raw ata that I need to calculate my figures? Are there any other solutions that might do the job better?

Thanks,
Bernie

 

[42OhmsPA]

Solar assistant.

 

[Zapper77]

From my limited testing, my system averages around 90%. If solar brings in 20 kWh...I only see 16 kWh.