The British thermal unit (BTU or Btu) is a traditional unit of energy equal to about 1055 joules (1 BTU / hour = 0.293 kWh). It is the amount of energy needed to cool or heat one pound of water by one degree Fahrenheit (Physical analogue: one four inch wooden kitchen match consumed completely generates 1 BTU). In science, the joule, the SI unit of energy, has largely replaced the BTU.
Generated electricity comes from a number of different sources (e.g. coal, gas, oil, nuclear and renewables). Each of these produces a different CO₂ output per kWh. We have taken an average figure of 470g per kWh.
We have taken an average figure of 190g per kWh.
Greenhouse gases are those that absorb and emit infrared radiation in the wavelength range emitted by Earth. In order, the most abundant greenhouse gases in Earth’s atmosphere are:
Where possible, CO₂ figures provided on this site take into account all the greenhouse gases shown above.
1,000 Watts = 1 kilowatt (kW).
1,000 Watts x 1 Hour = 1 Kilowatt hour (kWh).
Average cost (November 2015) of 1 kWh of standard electricity = 14.05p
Average cost (November 2015) of 1 kWh of standard gas = 4.9p
Average water cost (November 2015) = £1.98 per cubic metre (£0.00198 per litre).
It takes 1 kCal to raise 1kg (1 litre) of water by 1 degree C. 1000 kCal = 1.163 kWh.
The SI unit of power, equivalent to one joule per second, corresponding to the rate of consumption of energy in an electric circuit where the potential difference is one volt (V) and the current 1 ampere (A) – V x A = W
