Ususally measured in kilowatt-hours, energy delivered by an electrical utility via its transmission/distribution system. For purposes of sale, utilities often classify electrical energy according to the demand placed on the system.
Electrical energy is the flow of electrons along a circuit. The movement of electrons creates an electric current which can be connected to an end use like lighting or appliances. Electrical energy can also be transformed into mechanical energy (using an elevator) or thermal energy (by using a space heater). Conversely, mechanical, thermal, and other forms of energy can be converted to create electricity, as in wind turbines and biomass facilities respectively. Electrical energy is usually measured in kilowatt-hours (kWh) or megawatt-hours (MW).
A form of energy utilized by means of electromagnetic fields. Usually referred to as electricity. For direct current, electricity is defined as follows: W = U * I * t U - Voltage (in Volts), I - Current (in Amperes), t - Time period (in hours). The product of U * I gives us the electrical output (in Watts). If the network voltage is 230 V and we consume 2 A of electricity for the duration of 5 hours (230 * 2 * 5) we consume 2300 Watt hours, usually recorded in the form 2.3 kWh (kilowatt hours).
Electric utility and other classes of generators produce electrical energy, not a physical stream of electrons. This energy is typically transmitted in the form of alternating current (see AC power above). The actual use of electrical power over a period in time as measured by electricity meters. This use is expressed in Kilowatthours (kWh) of Megawatthours (MWh).