Electric energy consumption
2012 World electricity generation by fuels (IEA, 2014)
Electric energy consumption is the form of energy consumption that uses electric energy. Electric energy consumption is the actual energy demand made on existing electricity supply.
Overview
Consumption of electric energy is measured in watt-hours (written W·h, equal to watts x hours)
Electric and electronic devices consume electric energy to generate desired output (i.e. light, heat, motion, etc.). During operation, some part of the energy – depending on the electrical efficiency – is consumed in unintended output, such as waste heat.
Electricity has been generated in power stations since 1882. The invention of the steam turbine in 1883 to drive the electric generator started a strong increase of world electricity consumption.
In 2008, the world total of electricity production was 20,279 terawatt-hours (TWh). This number corresponds to an average rate of around 2.3 terawatts continuously during the year. The total energy needed to produce this power is roughly a factor 2 to 3 higher because a power plants' efficiency of generating electricity is roughly 30–50%. The generated power is thus in the order of 5 TW. This is approximately a third of the total energy consumption of 15 TW (see world energy consumption).