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Best answer by nealmurphy

Updated on 18/08/26 by Ben_OVO

Hi @Johnnyhornet 

 

First the easy one. The electricity should be measured in kWh on the meter. So to work out how much you’ve used since the last reading you simply take the old reading away from the current reading on the meter.

 

Now for the trickier one (science books at the ready)…

 

Gas meters can measure usage in cubic feet or cubic metres. If yours is measured in cubic feet then multiply the value by 0.0283 to get cubic metres.

 

The volume of a gas is dependent upon pressure and temperature and therefore varies. The volume of gas measured by the meter is adjusted by multiplying by a correction factor to take account of the temperature and atmospheric conditions. The correction factor used will be shown on your gas bill (e.g. 1.02264).

 

Next, the volume needs to be converted into a calorific value (CV) which is a measure of the energy released when a given volume of gas is completely combusted. This depends upon the gas’s composition. The CV usually ranges from 37.5 to 43.0 MJ per cubic metre. The value used should also be on your bill.

 

Finally. the thermal energy can be converted into kWh. 1 Watt is 1 Joule per second. 1 Joule is 1 Ws. 1 kWh is 1000x3600 Joules = 3.6 MJ.

 

So divide the CV by 3.6 to convert MJ into kWh.

 

There will be a test next week, so don’t forget to revise.

 

As mentioned below, the calorific value of gas changes every day and can range from 37.5 to 43.0. To find out calorific values used to calculate your charges you can visit: https://data.nationalgas.com/find-gas-data.

59 replies

nealmurphy
Newcomer
nealmurphySolved
Newcomer
March 16, 2022

Updated on 18/08/26 by Ben_OVO

Hi @Johnnyhornet 

 

First the easy one. The electricity should be measured in kWh on the meter. So to work out how much you’ve used since the last reading you simply take the old reading away from the current reading on the meter.

 

Now for the trickier one (science books at the ready)…

 

Gas meters can measure usage in cubic feet or cubic metres. If yours is measured in cubic feet then multiply the value by 0.0283 to get cubic metres.

 

The volume of a gas is dependent upon pressure and temperature and therefore varies. The volume of gas measured by the meter is adjusted by multiplying by a correction factor to take account of the temperature and atmospheric conditions. The correction factor used will be shown on your gas bill (e.g. 1.02264).

 

Next, the volume needs to be converted into a calorific value (CV) which is a measure of the energy released when a given volume of gas is completely combusted. This depends upon the gas’s composition. The CV usually ranges from 37.5 to 43.0 MJ per cubic metre. The value used should also be on your bill.

 

Finally. the thermal energy can be converted into kWh. 1 Watt is 1 Joule per second. 1 Joule is 1 Ws. 1 kWh is 1000x3600 Joules = 3.6 MJ.

 

So divide the CV by 3.6 to convert MJ into kWh.

 

There will be a test next week, so don’t forget to revise.

 

As mentioned below, the calorific value of gas changes every day and can range from 37.5 to 43.0. To find out calorific values used to calculate your charges you can visit: https://data.nationalgas.com/find-gas-data.

    J
    Rank 1
    JohnnyhornetAuthor
    Rank 1
    March 16, 2022

    Many thanks

    V
    Newcomer
    Vladneiru
    Newcomer
    June 15, 2022

    Please help to understand this readings.
    Our meters are reading in meters cub but we pay for KW 
    How the meters cub are converted in to the KW and how much is actual a unit that is read on the meter.
    Thanks

    M.isterW
    Rank 6
    M.isterW
    Rank 6
    June 15, 2022

    This website has a conversion calculator https://www.theenergyshop.com/guides/how-to-convert-gas-units-to-kwh

    1992 4 bed detached house. Solar PV + battery, Zappi EV charger, Mitsubishi Ecodan ASHP and i-life2 fan assisted radiators.... No gas 😊
      G
      Newcomer
      Gertie
      Newcomer
      July 5, 2022

      I am interested in solar panels at the moment so am looking to work out kwh usage.  I can calculate kwh and make and estimate for the CV.  But I cant for the life of me get a value near what my usage is calculated at by OVO  How can I find out whether OVO have my gas metre readings as a cubic metre or cubic foot measurement?

      Blastoise186
      Super User
      Blastoise186Super User
      Super User
      July 5, 2022

      Hey @Gertie !

      I can help with that. If you don’t mind, please can you post photos of your gas meter? I’ll need to see it in order to figure this one out. :)

      Securing energy by zapping security bugs... For that is The Blastoise Way! Remember, I'm just like you - AI Powered Evil Geniuses aren't Staff!
      G
      Newcomer
      Gertie
      Newcomer
      July 5, 2022

      Its a cubic foot meter Apparently listed as imperial meter. No. 021005

      Blastoise186
      Super User
      Blastoise186Super User
      Super User
      July 5, 2022

      Assuming that’s a meter reading, I calculate roughly 664988.1877 kWh. But this isn’t going to be perfect as I don’t have the exact formula to hand.

      Securing energy by zapping security bugs... For that is The Blastoise Way! Remember, I'm just like you - AI Powered Evil Geniuses aren't Staff!
      Tim_OVO
      OVO Staff
      Tim_OVO
      OVO Forum Legend
      July 6, 2022

      There’s a site I’ve found that offers this service, @Gertie - theenergyshop have a page for this here. 

       

      Can I ask what other factors you’re looking at when looking into solar PV panels in your home? Need advice from our solar panel members?

      Carbon neutral - we need a community to get there! My green tech: Aclara SGM 1411-B smart meter, Chameleon IHD6
      M
      Newcomer
      MaryH
      Newcomer
      September 15, 2022

      Hi all, can anyone advise, due to all the publicity around energy I have been looking at my bills in more detail and It appears we are spot on as average for electricity in a 3 bed house with two people but our gas consumption yearly is averaging out at 30000 KWH when average is around 12500. I appreciate not every home will be exactly the average but this is 2.5 times average which seems excessive. We have an old 1990 imperial gas meter in ft3 when I check the govt website for calculating this to KWh it does state that some older meters provide readings in cubic feet and not always 100 cubic feet. Could this be why as my supplier is using the calculation with x 2.83 and not 0.283 as it states on the govt website and a few other energy websites. When I calculate my readings using 0.0283  our average gas KWh is around 11500KWh which is more like the average. My supplier refuses to investigate, would anyone know how to confirm what readings my meter is providing, we have a combi A rated boiler, insulation double glazing and cook with electric. Only two of us so a shower/ bath each every day central heating not been on for months 

      Thanks in advance

      Mary

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