Just had a quick look at the emoncms email reports…
The solar report shows an incorrect starting position for me of -18,679kWh 
Use Solar
Monday 47.9 kWh -18,679.2 kWh
Tuesday 7.4 kWh 18,707.9 kWh
Wednesday 8.1 kWh 20.5 kWh
Thursday 15.2 kWh 17.6 kWh
Friday 35.3 kWh 13.0 kWh
Saturday 26.5 kWh 15.0 kWh
Sunday 19.9 kWh 15.2 kWh
Thanks @stuart, the solar_kwh feed needs to be created with either the power_to_kwh or wh_accumulator input process otherwise you get gaps in the data which then result in the kind of results your seeing.
Ah, thats the problem then.
I’m using a direct Kw/h reading from my inverter to drive the data logging (via my bluetooth code) - I suspect others are doing this as well.
Using the direct reading avoids issues when the power goes or the logging stops for a period of time.
Thats fine, I would make a parallel process with wh_accumulator in that case so that you have the best of both.
Trystan