Hello,

I'm hoping that someone here would be able to help out. I can't find any info on the CoCT's website how to interpret the smartmeter data...

I had an AMI meter installed in August, but somewhere the paperwork when missing and as a result it is only now that I am able to log on to COCT's website to see my smartmeter readings on the e-services site.

While the graph looks pretty and I am able to download a CSV file, I can't see how the CSV data is used to generate the graph and how that will be used to calculate my electricity bill. Perhaps it will make a bit more sense when I receive my first statement from CoCT, but in the mean time it would be nice to be able to put it in a spreadsheet and do my own calculations.

Here is what I see (for Nov)

 

What does the P1/Q1 etc mean?

Is S some sort of total for a given 15min period?

Is there some formulae, using the csv data, to calculate a daily import/export KWh value? I'm hoping to create a spreadsheet in order to track my monthly usage, forecast my bill, and check up on CoCT until I can trust what's going on here.

How does CoCT use this "rolling" figure, as someone called it in another post, to keep track of the monthly usage, or do they have to re-process all the source data again from start to the current data to know the net import/export value? Seems a lot more complicated than subtracting the current month's meter reading from the precious month's reading.

Anyway - if someone can give some pointers it will be much appreciated and I should be able to figure out the rest 🙂

Andre

 

 

Hi Andre,

I just got my meter last week on the 27th and have the same question. Did you ever figure it out?
Also today is the 4th of June and the CSV is just one day, the 27th of May. Is there a delay?

I figured P Q and S
S = Apparant power
P = Active power
Q = Reactive power (you want to get this one low)

S = Square root of (P^2 + Q^2)

P1 is import what you use from the City
P2 is export to the grid/

Each ling must be Pimport = P1 / 4 Pexport =P2/4


The City do 4 readings per Hr so that value you have to divide by 4

Edited June 9, 20251 yr by NoJ

Anyone know which values I should be comparing to my CT coil readings to check their accuracy? In other words, when the Sunsynk inverter reports grid power from the CT coil, is it reporting kW (active power) or kVA?

Also, any idea how CoCT computes the bill from this? Does it bill for reactive power?

On 2025/06/05 at 5:49 PM, Meint said:

I figured P Q and S
S = Apparant power
P = Active power
Q = Reactive power (you want to get this one low)

S = Square root of (P^2 + Q^2)

More specifically, I've worked out that S = sqrt((P1-P2)^2 + (Q1+Q2-Q3-Q4)^2). And I found https://clouglobal.com/the-four-quadrant-diagram-in-electricity-metering/ helpful in understanding why there are four Q values: basically it separately measures inductive and capacitive reactive power, during importing and exporting. I'm not convinced that formula is really meaningful: if you import 100W for t/2 minutes then export 100W for t/2 minutes (with no reactive power), then the average apparent power over t minutes is still 100W, not 0W.