Calorific value (CV) of gas - Is this information on my bills accurate?

As I am new to OVO from SSE, I think I have fathomed out the workings of my first OVO bill. Only one thing that seems to missing from my OVO bill that was on my SSE bill is the calorific value used towards accurate calculation. All it says on the OVO bill is to view the National Grid site for these values. I do know the value fluctuates and that probably an average of the fluctuations is used the finalize the figures but to me the actual figure used should be shown on the bill to enable myself to accurately check OVO figures to the penny. If anyone is interested I could put the National Grid values for each calendar month on this site.

Go for it! We love data here. :)

I think you are au fait with the OVO systems, so I will present the data at the end of the month if there is anyone out there that could use the values ;))

It looks like OVO along with every other gas supplier does/has to take the average CV of whatever period of days a bill applies to. So if trouble is taken to note CV value for each day of a period from National Grid is noted and and average taken, then the calculation is a simple one.

My remaining issue is why if SSE could show the CV used for the bill, why can’t OVO?

Calculation of average calorific value in accordance with the Gas (Calculation of Thermal Energy) Regulations 1996

Guidance on the calculation of thermal energy on the basis of determined calorific values

 Use of average daily figures Regulation 3 (2) states that the “average calorific value of gas so conveyed during any such period shall be calculated by adding the daily values…for each gas day in that gas period and dividing by the sum of the number of those gas days…”. National Grid is responsible for determining the daily average CV for each charging area. National Grid publishes this daily average CV for each charging area rounded to one decimal place in accordance with Regulation 4 (4) (set out in Appendix 1). National Grid then transmits this daily calorific value electronically to gas transporters and gas suppliers for their respective uses.

Further to previous comments about calorific value anomalies, I was interested in finding out what the variation in cost might be over a year given the criteria OVO have given on my bill:-

“The calorific value of gas changes every day and can range from 37.5 to 43.0”

The following table is based on using 1060 units of gas for 12months using CV from 37.5 to 43.0.

1060 units @ CV 37.5 = 11291.650 kWh = £1269.41

1060 units @ CV 38.0 = 11442.205 kWh = £1284.94

1060 units @ CV 38.5 = 11592.610 kWh = £1300.48

1060 units @ CV 39.0 = 11743.346 kWh = £1316.02

1060 units @ CV 39.5 = 11893.871 kWh = £1332.66

1060 units @ CV 40.0 = 12044.427 kWh = £1347.10

1060 units @ CV 40.5 = 12194.982 kWh = £1362.64

1060 units @ CV 41.0 = 12345.537 kWh = £1378.18

1060 units @ CV 41.5 = 12496.093 kWh = £1393.72

1060 units @ CV 42.0 = 12646.648 kWh = £1409.26

1060 units @ CV 42.5 = 12797.203 kWh = £1424.80

1060 units @ CV 43.0 = 12947.759 kWh = £1440.34

Without knowing the actual CV used by OVO, the average of the range above is 40.25.

Note that if the lowest CV is used (37.5) then any CV used between to a maximum of (43.0, then There could be a maximum overcharge up to £170. It could also be that an undercharge is possible but without OVO actually stating on each bill the actual CV used then each customer will have to resort to asking OVO which particular CV the have used to calculate a particular bill. I would appreciate a response from someone from OVO as this issue has been on the agenda for at least two years.

Hey @JGANLEY,

Thanks for a great conversation, 

The calorific value changes every day, so it’s not appropriate to put it on every single statement as there would be 30 odd values. The information comes from the National Grid.

It may be possible, if you contact Support for them to raise this to a specialist team to find out the values for a month statement. 

You might also be able to find out the calorific values from the National Grid.

Hope this helps. 

Thanks Emmanuelle_OVO.

I do know how to obtain daily CV from National Grid and also calculate daily and monthly averages. My questions are...why is the monthly CV not on my bill? As OVO must use a CV to help calculate the bill, then why do they not tell us this figure? SSE used to put the CV on the bill. I am sorry but to say it is not appropriate to put it on the bill is not satisfactory. It's like buying something for a shop and being told to work out the VAT yourself. I feel OVO are obligated to give all required data to enable customers to check the bill themselves. Afterall the CV average only needs entering once a month on the bill. I would be pleased for someone from OVO to publish the CV used for January. As a further point, I have raised this point with my MP and the requirement is being looked into. I do not want upset the apple cart. I just want to calculate my bill accurately myself. I am at present using the daily figures released by National Grid and have created a spread sheet which from readings and daily CV figures automatically gives exact costs but that is me doing it daily and if I can do it daily then OVO should at least be able to, once a month plus tell me how they have used the CV data, daily or averaged out over a month. Sorry, long winded I know but it is information that should be ailable OVO customers.

Regards

As I think I’ve commented elsewhere @JGANLEY I'm still not sure that an average figure is that simple. After all, it will not be just an average of each daily reading but an average at the various m3 conversion factors based on each daily reading. I realise this can be done but it looks more complex on that basis

I agree it may be complicated but my point is that it is not complicated for OVO and they should show all the data as was the case with SSE.