Utitity Bill (Gas+Electricity)

[Mr-H]

My supplier is NPower, but I have been thinking about a move. I asked them how I work out from 1 meter reading to the next, what the fuel used costs. For electric it's fairly easy - Difference between 2 readings, 2kwh of electric each day are charged at 12.58 and additional units 12.54. But for gas, the email response was 8 lines long. I have posted it here for information, and comment.
"Gas is a lengthy calculation as a process called sculpting is used. Basically, more higher units are charged over the winter months than they are during the summer.

You have an imperial meter so you deduct the readings to get the advance, you multiply by a figure of 1.0226400 and to convert into cubic feet you multiply again by 2.83. The calorific value is 39.1 so again you multiply by this figure. Divide the total of that by 3.6 and you will get the amount of kwh gas used.

From a read of 6713 12/01/09 to 6998 21/04/09, thats an advance of 285, use the calculation above and 8981kwh of gas were used. We sculpted over that period and 1812kwh were placed at 7.465p and the rest at the lower rate of 2.577p. If you put the same units over the months of October to January an additonal 700kwh would be higher and the rest lower meaning an additional balance."

What do they mean by 'sculpting'. Is it, as I suspect, another term for 'legal fiddle'? Does anyone know if other companies are more open (and therefore perhaps easier to understand with their calculations? Is it time for me to change? Should I write to the TV consumer programmes?

[factor-fiction]

Whilst there may or not be some justification for sculpting, I believe companies deliberately make these calculations so complex that no-one really knows whether they are on the best deal available with the one company never mind across the market. They can therefore keep telling us how great their deals are. Mobile phone companies use the same approach

[Mr-H]

I certainly would tend to agree. If I was to ask another company, I'd be comparing apples with carrots, not oranges and oranges!

[buildersmate]

Hmm. Pretty interesting. I knew nothing about sculpting, so researched a bit. The gist of the way gas tarriffs work (and I suspect you know this) is there are 2 rates of charge for the gas. The higher one applies for the first X units and the lower one after that. What's important (obviously) is that every year, a gas customer doesn't pay for more than the maximum number of the higher priced units - the ones at about 7.4p. It is supposed to charge the higher rate on the first 4574 Units per annum. Npower fouled this up, charged some customer for more than 4574 Units higher priced units, got rapped be OFGEM for it and got told to refund some customers. I suspect that these calculations they are now doing may be linked to checking you weren't overcharged?
See this attached link on Martin Lewis' MoneySavingExpert website - which I rate highly as a source of consumer advice - for an expose of what happened.
http://forums.moneysavingexpert.com/showthread .html?t=822299
The bottom line is you are going to have to work out over the annualised period how many higher priced Units they charged you for.

Regarding your desire to change company, I don't believe other companies did engage in sculping - and the ML website tends to confirm it was only Npower that shafted people in this way.