When I first had my PV panels fitted in July 2022, the ordered Tesla Powerwall was not yet available as stock was short; as I wanted to know how much energy was being produced, I had an Enphase Envoy unit fitted and connected to the Tesla Gateway. I had Enphase data for individual panels (IQ7 microinverters) and the Enphase app provided production figures etc. Once the first Powerwall was installed, I also had the full data provided by the Tesla app - and the two sets of data were ‘similar’ for PV panel production figures. I also have the fitted ‘Import / Export Meter’ as seems to be fitted on every installation I have ever seen.

Last year, I started noticing that there were large discrepancies between the Enphase and Tesla figures for solar production; this seems to have started when an Enphase ‘Metering Error’ was flagged up. At the time, my installers could find no reason for this and requested Enphase investigate, they eventually came back to me saying that Enphase had found a fault and had updated the software then reset the error flag. I then noticed that the discrepancy in readings was nearly double on the Enphase report and have had their engineers here several times to investigate. Finally, the engineer found that a CT clamp that fed impulses to the Envoy unit had been connected around the two cables from the two strings of microinverters; the CT clamp was then clipped on further down the line after the two strings had been combined within the Tesla Gateway and then the data agreed with that of the Tesla app!

Now the two units agree very closely in their data reports, it only remains to know why these figures are noticeably lower than the export figures as shown by the SMETS 1 Smart Meter! I have questioned this difference with my energy provider three times and they assure me that the smart meter is working properly. I am not inclined to enquire further but just accept that there are readings and readings! Regards, Toodles.