Any One Understand Gas And Electricity Unit Prices?

[hc4361]

I need to know if it is cheaper for me to heat my hot water by electric immersion heater water tank or by gas central heating for one hour.
The unit costs are:

Electricity 6.18p
Gas 2.45p

The immersion heater is 3kw.

[gingejbee]

^^^OP has already stated that they use Economy 7 off-peak....

[ummmm]

When our heating broke down and we had to use the immersion our electric bill shot up.

[hc4361]

Bright Spark, it's not as simple as that, sadly. One digit on the gas meter is not equal to one price unit, there is a mysterious complicated formula that I don't understand.

[Old_Geezer]

But it has to be a constant multiplier. It's the same volume of gas/amount of energy whatever units it is in.

Didn't the 31.7 times the meter change result in the number of paid for units not seem to work ? My gas bill seemed to suggest that was the multiplier for me, to change it into kWhrs.

[hc4361]

OG, having looked at my bill the only information re gas pricing is that 37 units on the meter = 1166 kw.

[whiskeryron]

I don't know if this is any good but have a look, https://www.google.co.uk/?gws_rd=ssl#q=go+compare+gas+%26+electricity

[Old_Geezer]

1166 kWhrs I suspect. (Watts are instantaneous, it costs you more to have them for a whole hour than a minute.)

Aye that fits. 1166/37 ≈ 31.7.

So whatever the question that defines it, that's the multiplier it uses to convert meter readings to kWhrs. Just take whatever gas reading increase you have noted and multiply it by that; and why it's right isn't so important.

[hc4361]

Thanks, OG. Still confused, bear with me.

Multiple the meter reading by what figure?

[Old_Geezer]

(Last minute edit, use 31.65857 ;-) )

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I get different values for the multiplication factor depending on whether I use your bill's figures, or mine ! It has to be down to rounding factors I guess but ...

Looking at my bill it worked out at about 31.7, but looking at the figures you give it looks more like 31.5: but I guess they are in the same ball park.

Your example where if the difference between your last meter reading and the present one, i.e. what you used, is 37, then :

37 * 31.5 = 1,165.5 kWhrs which ≈ 1166 so 31.5 seems close enough.

But using 31.7 it would have been

37 * 31.7 = 1209.9 kWhrs which ≈ 1210 which isn't as close but not that far out.

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I know what you mean about the complex equation they say they use. But it doesn't seem to me as if they use what they say they do. Let me see what my gas bill actually says regarding working it out :

meter reading (in m³)
* calories per m³ (39.2)
* fiddle factor called 'volume correction' (1.0226400)
÷ conversion to kWhs (3.6)

So... 39.2 * 1.02264 / 3.6 = 11.13541333

I don't see how they can possibly be claiming that they use about 11.

Unless .... just had a thought ... they are using a metric meter as an example and assume they read m³ directly. Whereas there are plenty of imperial meters out there reading in, well I'm not sure, cubic feet I'd suspect. So they'd need a further multiplication factor of some value.

[hc4361]

Thanks for all your help, OG. You've certainly gone the extra mile.

Why oh why can't they simplify the bill?