Half hour time offset between Bright & n3rgy data

lohr500

Hello everyone,

I'm wondering if anyone else has noticed a 30 minute difference between the downloaded half hourly usage on the Bright and n3rgy systems?

The screenshot below shows the raw csv data from the 30th August downloaded from the two sources. As can be seen, the n3rgy usage values appear to be 30 minutes later compared to Bright.

I have aligned the times on the spreadsheet.

Any ideas please as I am puzzled since isn't the data source for both supposed to be the same?

Thanks

 

Scot_39

One using start time one using end of the 1/2 hrly meter slot.

Would be my simple guess.

So align energy not timestamp as such - right column up 1.

Both will be for same half hour period.

Suspect 23 start 2330 end.  But thats only my take as I don't report my data half hourly.

And in part only in case that's gmt so as get full data set for dst calander day when some apps / tools- like the api access - from other posts recover 50 slots not 48

And gotten lost - or not paid attention - when start to get conflicting interpretations -  in past threads on how each of these sites and the different apps log or Change - in gmt or dst - their time stamping.

But there will be real experts who will confirm exactly what time stamps are used.

lohr500

Thanks @Scot_39

I'm sure you are right in that one uses start time and the other uses the end time of the 1/2 hrly slot.

So does this indicate that there must be some manipulation of the data once one or either of the requesting companies retrieve the data from the meter. Surely the meter won't output different data formats for the half hourly data requests, unless there is some fancy format coding instruction in the data request that the meter receives.

I will look back at the GMT/BST hour shift as well to see what happens with the data from both across a clock change. 

EDIT : Just checked both downloads for a couple of days either side of the March 31st date for the switch to BST. Both data sets only have 48 entries per day across the 30th March, 31st March & 1st April.

So as far as Bright & n3rgy are concerned, the data must stay as GMT throughout the year, regardless of the actual GMT/BST time.

Scot_39

I am not sure.

The slot is the slot - its the same usage.

Edit : And over any 24 hr period you will be billed for 48 1/2 hr slots.  
The problem is on TOU aligning those 1/2 hr slots with what you are being told as variable or fixed time of use tariff rates.


The thing I am not sure about is how that slot might shift.

So is a meter timestamp of 23 to 23:30 - if gmt - then reported by app or treated by suplliers billing as 23:00 to 23:30  or midnight to 00:30 in summertime.


I'll leave that to someone on Agile or an EV tariff using 1/2 hrly billing or tracker with its daily rate if based on the 48 hr slots can comment with a lot more authority.

I dont look 1/2 hrly - nor do I allow my supplier to access it - I never opted in.

I only log daily data - in summer as my meter is afaik set to stay gmt - the daily figures aren't correct until 1 am (or at least the date stamps for previous days reported usage shift by a day between midnight and 1 am then correct ).

I cannot easily benefit from flexible TOU on e10 for old meter switched nsh , nor have supplier offered demand savings sessions on my tariff, when asked.  So never worried about 1/2 hrly.

Ildhund

Yes: n3rgy stamp the usage figures with the time at the end of the half-hour slot. I'm not sure for the reason for this, but it is in fact logical: the energy hasn't been used and measured until the half hour has passed. Perhaps the advent of MHHS has played a part. 

lohr500

Thanks @Ildhund

All of my interest stems from trying to figure out how I am going to check the billing for my new Tomato Energy tou tariff when I finally receive it.

At the moment the TE partner website, myWatts, is not showing the consumption data, nobody seems to be able to get a definitive answer from TE about any GMT/BST time shift on their tou hours and I've only just switched so I have yet to receive any detailed billing.

My plan is to use the downloaded data from Bright or n3rgy sites to reconcile against any TE usage/billing data once I receive it.

Reed_Richards

I had noticed this and assumed the explanation was as has been suggested; Bright uses start time and n3rgy uses end time.  Since you don't know how much energy you have used in a half hour until the end of that half hour then the end time seems much more logical.