At present, the corporation has set 100,000 therms a year as the threshold at which it offers a supply on contract.
I converted that into therms and worked out the saving, which amounts to £53 per year.
The working group's report was based on an anticipated price of 34p per therm, and the profit of £157 million was calculated on that price.
Interruptible supplies are no longer available to growers with consumption below 250,000 therms a year.
Under the new schedule, interruptible supply will be available only to single premises taking in excess of 250,000 therms per year.
He also pays roughly the same per unit of electricity (though that may change) and per therm for gas.
For convenience, figures for the last 10 years in pence per therm, and figures for fuels sold to domestic consumers, are given below.
We could use the round figure of 10 therms to a gigajoule.
