On 23/07/2019 12:51, Tim Streater wrote:
In article , Andy Burns
wrote:

Jim S wrote:

I want to use a comparison site to, well, compare energy suppliers.
I know my total meter readings for the year, but I want to convert to
kWh.

Multiplying m^3 by 11.2 will give you fag packet kWh

Do they guarantee the pressure? If the pressure varies during delivery
then how do you calculate it? Come to that, how do they bill you
reliably?


Your meter has a regulator on the top - the pressure delivered to your
gas pipework is determined by the regulator (not the pressure in the
pipe on the street, which might go up/down according to demand, changes
in temperature (Boyles law).

The one thing that does vary is the calorific value of the gas (energy
per cubic metre). This varies by area and time of year and is shown on
your gas bill. Mine varies between 38.8 and 39.4 MJ/m3.
The reason for this is that although natural gas is nominally methane,
the stuff that arrives in your home contains other compounds, e.g.
ethane, CO2, which depends on where the gas originates.
e.g. gas coming from Morecambe Bay (Lancs) will be different from that
arriving at Bacton (Norfolk).