n3rgy vs Glowmarkt API (Bright app/Hildebrand): different tariffs/unit rates

sebtomato

Hi,

As far as I am aware, there are two mechanisms to get granular data (30 minute slots) from a smart meter:

• n3rgy website
• Bright app (Glowmarkt API)

I have registered for both, but getting different data, particularly on cost.

I am with EDF, on Economy 7.

According to the n3rgy tariff data, I am on off peak tariff between 23:30 and 08:30 BST, apart from 01:30 to 03:30, which is peak tariff. That would indeed give 7 hours of off peak electricity during each night, and matches the EDF times published on their bills.

n3rgy doesn't give a cost per period, just consumption (kWh) and rate/tariff applicable for that period.

HOWEVER, if I download the consumption and cost data using the Glowmarkt API, it would seem that the rate applied at off peak between 23:30 and 08:30 each day, so 9 hours per night. No peak gap during the night.

The Glowmarkt API doesn't provide tariff data, but only consumption (kWh) and cost per period (pence), so I am calculating the effective rate (cost/consumption).

Unfortunately, neither n3rgy or Glowmarkt return the R1 or R2 values, only values per 30 minute intervals.

Which one is correct? Where does the n3rgy site gets its tariff data from?

What tariff EDF is going to use when billing me? Peak tariff between 01:30 to 03:30, or off peak tariff (as per the Gloamarkt data)?

MWT

n3rgy only uses data it retrieves from the meter.

I just checked mine and it correctly reflects the incorrect information that is loaded on my meter and visible on my IHD.

What matters, and what the Bright data may be reflecting is which register the consumption is being accumulated into...

sebtomato

MWT said:

n3rgy only uses data it retrieves from the meter.

If both n3rgy and Bright are retrieving data from the meter, then how can they be different, in term of tariff/cost (consumption is the same)?

Clearly, Bright believes the cost is different between 01:30 and 03:30 compared to n3rgy.

MWT

EDF are going to bill you based on the register totals for R01 & R02, so what matters for your actual billing is what those registers hold.

The usage data that both n3rgy and Bright show does not come from the registers, it comes from the half-hour 'buckets' that are recorded independently from the main registers.

So what you see with each of those sources regarding cost, is their mapping of the tariff data onto those half-hour buckets.

n3rgy make no attempt to do anything more than give you either the half-hour use, or the tariff data, they do not try to combine it together.

Bright do try to combine the data and for some reason are giving you a different interpretation from n3rgy.

... but again, what matters for your actual billing is what is in R01 & R02, so if you've not already done so, verify that using manual meter readings and the data from either Bright or n3rgy and you will know the answer... 

sebtomato

Interestingly, some of the data is now available on the EDF website, and doesn't match other sources either (n3rgy or Bright), when it comes to total usage per day, or split between day or nigh energy (kWh).

Even if we account for differences between UTC or BST time (I don't what EDF use to define a day), still some large differences.

I find it fascinating that several sources cannot come even close to providing the same data.

Quite worrying when it comes to billing accuracy.

sebtomato

MWT said:

EDF are going to bill you based on the register totals for R01 & R02, so what matters for your actual billing is what those registers hold.

I agree, but unfortunately, I can't find any APIs or systems that can export those registers for specific intervals.

Even the IHD doesn't display both registers, just show the total (sum of both registers).

MWT

sebtomato said:

MWT said:

EDF are going to bill you based on the register totals for R01 & R02, so what matters for your actual billing is what those registers hold.

I agree, but unfortunately, I can't find any APIs or systems that can export those registers for specific intervals.

Even the IHD doesn't display both registers, just show the total (sum of both registers).

Only your supplier has access to that data, and of course you can take manual meter readings of those registers any time you want.

MWT

sebtomato said:

Interestingly, some of the data is now available on the EDF website, and doesn't match other sources either (n3rgy or Bright), when it comes to total usage per day, or split between day or nigh energy (kWh).

Even if we account for differences between UTC or BST time (I don't what EDF use to define a day), still some large differences.

I find it fascinating that several sources cannot come even close to providing the same data.

Quite worrying when it comes to billing accuracy.

Billing accuracy shouldn't be in question as it isn't using the data that you are having problems reconciling.

I'm with Octopus and the half-hour data provided there is an exact match for what I see from n3rgy, I'd have expected half-hour data from EDF to be similarly exact, but if you are trying to reconcile the half-hour data with the register snap-shot numbers you may find some differences as the timing of those snap-shots may not fall exactly on a half-hour boundary.

That doesn't matter from a billing perspective as whatever they use for the closing reading this billing period is the opening reading for the next billing period.

Swipe

sebtomato said:

MWT said:

EDF are going to bill you based on the register totals for R01 & R02, so what matters for your actual billing is what those registers hold.

I agree, but unfortunately, I can't find any APIs or systems that can export those registers for specific intervals.

Even the IHD doesn't display both registers, just show the total (sum of both registers).

Yes, very annoying that it only shows the combined total. Defeats the object of an IHD if I still have to keep going outside to take a reading.

MWT

Swipe said:

sebtomato said:

MWT said:

EDF are going to bill you based on the register totals for R01 & R02, so what matters for your actual billing is what those registers hold.

I agree, but unfortunately, I can't find any APIs or systems that can export those registers for specific intervals.

Even the IHD doesn't display both registers, just show the total (sum of both registers).

Yes, very annoying that it only shows the combined total. Defeats the object of an IHD if I still have to keep going outside to take a reading.

Yes, it is a little frustrating, as it is usually showing a different register, the 'Total Import' register, which even if you are not currently on E7 or another tariff using multiple registers, may not be the same as R01, so take care if giving manual meter readings...

 

sebtomato

MWT said:

sebtomato said:

Interestingly, some of the data is now available on the EDF website, and doesn't match other sources either (n3rgy or Bright), when it comes to total usage per day, or split between day or nigh energy (kWh).

Even if we account for differences between UTC or BST time (I don't what EDF use to define a day), still some large differences.

I find it fascinating that several sources cannot come even close to providing the same data.

Quite worrying when it comes to billing accuracy.

Billing accuracy shouldn't be in question as it isn't using the data that you are having problems reconciling.

If the off peak time is not confirmed between the various sources, and sum of kWh in peak or off peak hours doesn't match at all (not even close), then yes, billing will be questionable.