Power 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.

Consumption of electric energy is measured in watt-time, or precisely multiples of watt-hours (written W·h, equal to watts x hours) which is the universal measure of Energy,

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) or 20.279 petawatt-hours (PWh). 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 plant's 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).

In 2005, the primary energy used to generate electricity was 41.60 Quadrillion BTU [12, 192 TWh] (Coal 21.01 quads [6,157 TWh], Natural Gas 6.69 quads [1,960 TWh], Petroleum 1.32 quads [387 TWh], Nuclear electric power 8.13 quads [2,383 TWh] , Renewable energy 4.23 quads [1,240 TWh] respectively). The gross generation of electricity in that year was 14.50 Quads [4,250 TWh]; the difference, 27.10 Quads [7,942 TWh], was conversion losses. Among all electricity, 4.84 Quads [1,418 TWh] was used in residential area, 4.32 Quads [1,266 TWh] used in commercial, 3.47 Quads [1,017 TWh] used in industrial and 0.03 Quads [8.79 TWh] used in transportation.

1 Quad = 1 Quadrillion BTU = 1 x 10¹⁵ BTU = 293 TWh

16,816 TWh (83%) of electric energy was consumed by final users. The difference of 3,464 TWh (17%) was consumed in the process of generating power and lost in transmission to end users.

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