Electron-volts
An electron-volt (eV) is used in the fields of atomic and particle physics. It is the amount of energy gained or lost by a single electron when it is accelerated through an electric potential difference of one volt.
Therm (EC)
The Therm (EC) is a unit of energy primarily used in the United Kingdom for billing purposes in the gas industry. It is defined as 105.5 megajoules (MJ). The "EC" in Therm (EC) stands for European Community as it was created to standardize within European countries.