"The CV of gas, which is dry, gross and measured at standard conditions of temperature (15oC) and pressure(1013.25 millibars), is usually quoted in Megajoules per cubic metre (MJ/m3)".
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So they're claiming its a constant 1013.25 millibars; allegedly throughout the whole system. And as pressure can make a difference, at least so I'm told, presumably its open anyone with the necessary measuring equipment to argue with them about this, as well.
To clarify and as a follow up to all the replies this is the situation:
At the bottom of my statement it states"this is how we calculate your bill" stating a CV of 39.3 the actual amount they charge is based on an average of 39.57CV but they dont tell you that so it looks like they are overcharging.
Using links from above posters I checked the CV for the dates and area and my figures state 39.0 which would be the one they use at the bottom of my statement and I get an average of 40.22 CV for the period in question.
So back to Bulb :-) Its only a few pence and some will be in my favour but their statements are all over the place.
AIUI the regulators keep a constant pressure _compared to atmospheric_.
Bearing in mind that atmospheric ranges from under 900 to over 1050 this will affect the amount of gas you get - by 15% or so. Run you heating in a high.
BTW Wikipeda says 1010.25 is the standard atmosphere. The gas _has_ to be above that, but I don't think by very much. A quick google suggests ~21mb.
I guess there are pressure sensors widely distributed around the local network that monitor the pressure to ensure that the mains have enough pressure, which is surely at least a good fraction of a bar. There is a regulator (a bit like a divers' demand regulator) with your gas meter, and this is what sets your nominal 21 millibar (above atmospheric) after the meter.
You are making the mistake of assuming that Bulb Energy is selling gas. They are not, they are selling contracts on the basis of meter readings.
Much the same way that certain "electricity suppliers" claim that all their energy is green, even though it isn't, really. It's just that their green purchase contracts, averaged over time, balance their "green" sales (and I'm not even sure if Ofcom monitor this).
It's all c*ck anyway. These people are just billing operations, not actual suppliers. And it all comes via the one grid, so to talk of "using green sources for our power" is grade one horseshit.
So that one of these figures is what used to be called and maybe still is a "worked example". In the "old days" the bills were printed in two stages - the body of the bill including the worked example, was printed by one process, and the figures and the address etc were very obviously printed by another process and then merged . A bit clunky in other words. However nowadays my bills appear to be printed in one go on what appear to be inkjets and given modern fast processors there's probably no reason why they couldn't if they wanted, use the correct figures and calculate the worked example on the fly before merging that into the bill. And then at least they'd have at least one more satisfied customer.
If you shuffle back and forth along potential start and finish dates for CV figures for the billing period I think you'll eventually find a range which produces a figure which matches the figure on your bill
Basically if you're paying a good i.e cheap price for a staple commodity such as gas, then unless they're consistently lucky with their forward buying then the only way they can do this is cut back on their support operations. The people you contact may quite possibly be employees of a call centre with no technical knowledge about billing. Their responses may well be monitored, as will the time they take to get you off of the phone. It's not a job you'd really want to wish on anyone - except an enemy.
"Our supplier produces the bio-gas through anaerobic digestion and injects it into the national gas grid at the nearest point to production. We draw out an equivalent volume of gas from the nearest national gas grid point to our Parliament Street Garage, where it is compressed and stored until the bus is fuelled up each night."
You can be more efficient in your support operations to reduce costs.
One way of doing this is by not supplying confusing bills necessitating customers to query the amount. In this case it is simply that they quote one figure and then calculate the bill using another.
The quality of customer support has nothing to do with the price you pay. Often the more expensive suppliers have the worst customer support.
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