Ovo Energy’s units mix-up tripled couple’s energy bill

A couple were overcharged more than £10,000 on their energy bill over a period of six years when their energy supplier Ovo Energy mistook their metric readings as imperial. As a result of the mix-up between metric and imperial units, the couple were charged three times as much as they should have been charged for their energy.

The problem started when Ovo Energy installed a smart meter in their home in 2016. After the smart meter was installed, they faced higher energy bills, which continued to rise. The couple, Bernard and Pat Hampson, spent hours on the phone to their energy company to sort it out but got nowhere.

Bernard Hampson said, “It turns out they had been taking our metric readings as imperial and then converting it to metric – so we were being charged three times what we should have been.”.

After the couple took legal action against Ovo Energy in November 2022, the case was settled out of court. Ovo Energy agreed to repay the couple over £10,000 that they overcharged them plus £6,000 in interest and compensation.

A spokesman from the legal firm that represented the couple said that there could be thousands of people facing similar situations.

Ovo Energy apologised for the couple’s billing errors and the time taken to resolve them. This problem could have been avoided if they only used one measurement system. If they used the metric system only, there would have been no need for conversions and no dual units mix-up.

It is not the first time that there has been a mix-up between dual units (e.g., see Road speed units mix-up could have been fatal MV article) and it surely will not be the last time. If the UK ditched the imperial system and just used the metric system for every purpose, it would prevent situations like this. It serves as a salutary lesson to the Government that is committed to entrenching the dual units muddle that we face in the UK. This situation exposes the folly of using dual units.

This story was published in the 6-7 May 2023 edition of i weekend newspaper (p39), which you can see here:

4 thoughts on “Ovo Energy’s units mix-up tripled couple’s energy bill”

  1. Shades of the Gimli Glider and the Mars Climate Orbiter! And who knows how many other mishaps have been caused by this kind of measurement muddle! 😦
    Time for all countries that are not 100% metric to get there asap.


  2. This is baffling because electricity meters have always been read in some metric unit. The earliest dial-based meters recorded in ampere-hours, but with AC distribution they changed over to kilowatt-hours to deal with voltage fluctuations. I have personally never had one that didn’t record usage in kilowatt-hours (kWh). However, Wikipedia says that some measure in megajoules (MJ). 1 kWh is 1,000 W x 3,600 seconds = 3.6 MJ.

    At some point gas meters changed from measuring in cubic feet to cubic metres. However, if the meter was measuring cubic feet but that was being interpreted as cubic metres, it wouldn’t be wrong by 3 times – it would be wrong by more like 35 times! I would be surprised if any ‘smart’ gas meters were designed to read in cubic feet.

    I think it’s much more likely that it’s an electricity reading in megajoules was being interpreted as kilowatt-hours, and therefore 3.6x the consumption. That does not change the fact that the supplier should be aware of the units that the meter is reporting.

    Liked by 1 person

  3. There are still some gas meters measuring in cubit feet out there. It sounds as though this customer had such a meter. The new smart meter would have course work in cubic metres.

    Gas meters that register in cubic feet are read to the nearest 100 cubit feet. Tens and units are ignored for billing purposes; there is no need for such accuracy.

    As Mike Dimmick explains, there are approximately 35 cubic feet in a cubic metre. That is 0.35 hundreds of cubic feet to a cubic metre, or nearly three cubic metres to 100 cubic feet. Either unit would be converted to kilojoules to calculate the bill. The conversion from hundreds of cubic feet to kilojoules would therefore be nearly three times as the conversion from cubic metres to kilojoules. This would explain the overcharge by three times. The energy company was at fault for failing to change the conversion factor.


  4. Metricmac,

    This type of problem would never occur if the gas company would just upgrade the remaining meters. The entire meter would not have to be changed, just the metering unit.


    You will need to scroll down to see the picture of the gas meter.

    I’m sure that as long a dual units are used out there, this type of mistake will continue to occur.

    I wonder how many meters out there are still in cubic feet compared to cubic metres.

    Liked by 1 person

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