Negative tariffs

My tariffs are showing as negative in the Bright app. I don't have solar panels, and while it would be nice to have negative tariffs it's unlikely to be accurate..


  • Mine turned negative on 21st Dec making the cost calculations useless as there's a mix of positive and negative costs. Is this due to any action from the supplier - mine is Shell?

  • I can concur, Electricity unit rates went negative on the 20th December 2022 for me, Shell is my energy supplier too

  • I can advise that the unit rates / standing charges shown in the app are based on data provided by your supplier. The way the system works is that the supplier uploads via the DCC the rates as shown in the app. these will also be presented in the in the home display. The Bright app. pulls the data from your meter and if it was incorrectly set by your supplier then it will show up wrong. Whether you are are actually being billed correctly is a different matter - and probably your bills will be correct as the billing system operate independently, it is just that your supplier is uninterested in this particular element of smart metering amongst probably a whole host of other customer service failures.

  • Thanks for the response.

    Oddly, the rates shown on the in-home display are correct (as is their app). Perhaps when Shell push the new rates to the DCC on 1st Jan things will sort themselves out, failing that I'll have a chat with them.

  • Thank you to @johnpo - you are exactly right. The display publishes the cost of consumption as delivered by the meter, whereas for our APIs we retrieve the separate standing charge and rates so that we can do things like support Agile - and do future tariff comparison. These problems are always down to the supplier.

  • I have approached Shell support via email and they have responded quickly, but only asking for more details, which I have provided

    I'll feedback anything I learn so the community can be informed.

  • edited January 2023

    It's not just Shell...I'm with Eon-Next and my electric tariff has also gone negative on Nov 24th (I think).

    Currently Bright is showing a unit rate of -32.516 p/kWh

    and a standing charge of -15.996 p/day

    Just uploaded some manual readings for the start of the year so it'll be interesting to see what they reckon my December bill is!

    (and just to clarify, as it seems different from the points made above - my IHD's are showing the correct figures - only Bright is wrong).

  • Good morning all - and a very Happy New Year to you!

    Please be reassured, your bill is calculated independently of what is loaded on the meter - it is only when you are retrieving your data via third parties like us that the tariff being loaded correctly becomes so transparent. 

    The vast majority of the time it is correct - and perhaps having customers ask to have their tariff load fixed will encourage suppliers to get it right 100% of the time!

  • Thanks Jane....

    But in my case the only thing that looks wrong is Bright itself - everything else is correct.

    Bright is showing my December electricity cost as -£81(ish) whereas the CAD was fine.

    So to me that looks like the supplier end is fine and Bright is doing something odd?

  • This is because the Display CAD works is that it retrieves the calculated cost of consumption directly from the meter - whereas our system captures the separate standing charge and rates(s) and timeslots from the meter so that we are able to support tariffs like Agile and offer services like our smart tariff comparison tool.

  • I'm definitely not grasping what's happening then... If Bright is the only thing that's incorrect - where is it getting it's figures from?

    Like I said, everywhere else is correct - the meter itself (so despite what you've put above this cannot be where the figures are coming from unless the tariff is held in two different places), the original IHD, my CAD, bill from Eon, etc.

    Sorry!! Just trying to get my head around this...

  • The meter calculates the cost of consumption locally - and I've no idea how it does that and what it uses. And your Glow Display matches your original IHD because they both take the output of the meter's calculation. Your bill is correct because the supplier uses their billing system to calculate your bill - not what is loaded on the meter.

    The tariff is apparently held in a different area to the where the calculated cost of consumption is - but this isn't my area of expertise in terms of understanding all the technical details. I'm sure it is described somewhere within the 1,800 odd page Smart Energy Code that prescribes how the meters should be set!

  • Resolved for me by Shell.

    I sent them a message with the issue and they forwarded it to their IT team and it was resolved overnight :-)

  • Unfortunately it's never that easy with Eon-Next - basically they're not interested because from their point of view:-

    "On our side your meters are set up correctly and sending the correct information every month."

    And they are correct because everything they care about is correct...Disappointing really.

  • There is an interesting question about supplier's obligations and meter tariff loading - I'm going to ask the regulator what the official policy is.

  • Shell have sorted my DCC rates out.

    Happened for the midnight update.

    Took them about a week from me sending their support a message.

  • edited January 2023

    My tariffs have also corrected themselves on Sat 7th - despite 3 Eon-Next support agents telling me there was nothing wrong in the first place.

    Interestingly, looking back, it looks like after it went wrong on Nov 24th it was actually correct again on Dec 26-29th before going negative again on the 30th up until Saturday. Very strange.

  • Negative values are due to rounding in the maths somewhere. E.g. my tariff says -31.846 p/kwh and should be 65.535-31.846 = +33.690 which Eon displays. Probably limited to 16 bit number 65535 and the new exorbitantly high rates have meant numbers higher than catered for so overflow.

  • My Shell electricity tariffs have gone negative again after they did another update 😕

  • Just dropping in to commend you all for your persistence - and @spiderbridge you are quite right - it is down to the way that something hasn't been set properly. I always feel rather sorry for the general customer service agents as they either don't know, or don't know how to help. What is always frustrating, for you and us, is when they get insistent that the fault is with us....

    Keep up the good fight everyone!

    Of course tariffs are going to be reset again on 1 April aren't they? sigh....

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