World

Energy supply

Total energy supply (TES) includes all the energy produced in or imported to a country, minus that which is exported or stored. It represents all the energy required to supply end users in the country. Some of these energy sources are used directly while most are transformed into fuels or electricity for final consumption.

Energy supply per capita

The per-capita energy supply is a function of economic development as well as the structure of the economy – countries whose economies are largely services-based will use less energy per capita than comparable countries whose economies are focused on heavy industries like iron and steel or pulp and paper.

Energy transformation

Energy sources, particularly fossil fuels, are often transformed into more useful or practical forms before being used. For example, crude oil is refined into many different kinds of fuels and products, while coal, oil and natural gas can be burned to generate electricity and heat. Other forms of transformation, such as extracting gas or oil from coal, play a relatively minor role in the energy systems of most countries.

Oil refining

One of the most important types of transformation for the energy system is the refining of crude oil into oil products, such as the fuels that power automobiles, ships and planes.

Electricity generation

Another important form of transformation is the generation of electricity. Thermal power plants generate electricity by harnessing the heat of burning fuels or nuclear reactions – during which up to half of their energy content is lost. Renewable power sources generate electricity directly from natural forces such as the sun, wind, or the movement of water.

Final energy consumption

Total final consumption (TFC) is the energy consumed by end users such as individuals and businesses to heat and cool buildings, to run lights, devices, and appliances, and to power vehicles, machines and factories. It also includes non-energy uses of energy products, such as fossil fuels used to make chemicals.

Some of the energy found in primary sources is lost when converting them to useable final products, especially electricity. As a result, the breakdown of final consumption can look very different from that of the primary energy supply (TES). Both are needed to fully understand the energy system.

Energy consumption by sector

The sectoral breakdown of a country's energy demand, which is based on its economy, geography and history, can greatly impact its energy needs and which energy sources it relies on to meet those needs – such as fueling automobiles, heating or cooling homes or running factories.