Increased power consumption following Solar PV installation

itm2

https://forums.moneysavingexpert.com/discussion/comment/82053604#Comment_82053604

The "Before" data was download from the Octopus customer portal. The "After" data was derived from the inverter - I have a Waveshare RS484/ethernet adapter connected to it, and am uploading the data to Home Assistant/Predbat for analysis.

Qyburn

I suggest doing a sanity check using your actual meters.

(1) Take readings for Import and Export from your smart meter. Take Generation reading from youyour generation meter. Let's call these I1, E1 and G1.

(2) Take another set of readings at a convenient later date, call these I2, E2 and G2.

(3) Calculate actual house use as (I2 -I1) + (G2-G1) - (E2-E1)

Compare with inverter figures for that period.

Reed_Richards

Take readings for Import and Export from your smart meter. Take Generation reading from your generation meter.

Do they still put separate generation meters in contemporary solar PV installations? Mine is in my meter cupboard but I couldn't spot one in the OP's photo. The alternative would be to incorporate the metering into the inverter.

itm2

I think I may have got to the bottom of the problem. I have been misinterpreting the data from Octopus. The data is showing kWh values every 30 minutes. This represents the total energy consumed over a 30 minute period. So to compare each of these values with the home load figures from the inverter or Fox app (which I have been collecting every 30 minutes) I need to double each Octopus value (or add two 30-minute values together).

So each 350kWh value in the Octopus data, representing half an hour's consumption, is the equivalent of a 700W inverter reading which remains constant for 1 hour. Schoolboy error :0(

The inverter values do still look a little high, but well within the bounds of variations in appliance use and calculation error margins, as well as factoring in the energy consumed by inverter itself.

Qyburn

https://forums.moneysavingexpert.com/discussion/comment/82054124#Comment_82054124

Generation meter was an MCS requirement when ours was installed Summer 2024.

QrizB

Schoolboy error :0(

Don't be too hard on yourself, that's exactly the sort of thing I'd do!

I'm glad you've established the problem, anyway :)

Heedtheadvice

Ah, comparing energy with power! Fooled ys all by listing a table both columns as energy.

( note you last post has an error too as 350kWh is an awful lot, presume you mean 350Wh or 0.35kWh ).

That is where running a kettle for 30mins duration would have been useful?