Stressed with energy comparison sites - help please

basmic

Every month, often without fail, I read my meters.

I am with Scottish Power's Online Energy Saver 4 tarriff, which has seen me right for some time.

I then do an annual consumtion, using uSwitch and Energyhelpline, and have done so for over a year now. If I have a 359 day reading, I divide my readings by 359, then multiply by 365 - giving me an accurate, but not exact, estimate of my annual usage.

For the last 3 months, my annual consumptions were:

Gas... Electric. Date
7211.. 4686......21/05/09
7146.. 4593......02/07/09
7110.. 4564......30/07/09

This month, gas was 7168 and electric was 4528 - gas has gone up slightly, but not much.

So I feed those numbers into the aforementioned comparision sites - and they tell me my annual usage is now £805 - £194.99/year for gas and £610.43/year for electric. :eek::eek:

Last month's readings, 7110 gas and 4564 for electric, spouted out £298.71 and £418.12 respectively - giving me an annual usage of £717.

Can anybody explain?

penrhyn

Two things, you are subtracting your opening meter reading from your current reading.

Unit of electricity = 1 Kwh.

1 Unit of gas = 1 cubic metre or 100cuft (British Thermal Unit) and must be converted to Kwh before entering into the comparison site.

The majority of customers have a credit meter which records the amount of gas you use. Gas consumption is measured in units. These gas units need to be multiplied by approximately 31.3 to convert from the units used according to the meter or bill into kilowatt-hours. Exact conversion figures from gas units to kilowatt hours are as follows:

• Multiply your units used by 2.83 to give you the number of cubic metres of gas used. (If you have a new meter measured in cubic metres you do not need to do this).
• Multiply by the temperature and pressure figure (1.02264).
• Multiply by colorific value (39.25)
• Divide by 3.6 to get the number of kilowatt hours (kWh)

sidefx

Why not just enter your annual or monthly payment amount? It might make things a bit simpler.

penrhyn

sidefx wrote: »

Why not just enter your annual or monthly payment amount? It might make things a bit simpler.

Indeed but it gives a far less accurate result.

basmic

penrhyn wrote: »

Two things, you are subtracting your opening meter reading from your current reading.

No, the gas readings are already converted to kWh in Excel, in my home made spreadsheet.

basmic

I've found my problem anyway - I got the gas and electric figures the wrong way round, when entering them into the sites...oops! :o

penrhyn

That will explain why I thought you were a bit low on the gas figures, best of luck with compare the meerkat et al.