If you have the time and inclination, you might want to look at my story on connecting my simple PV system to emoncms. I didn’t use emonpi or the 433 Mhz radio for my setup as I had other options.
For better or worse I bought my CT off ebay - I didn’t think the ones in the shop would fit my service feed.
My PV system is so small, I didn’t need to change the resistor in CT4.
Good luck.