6.4A - The Energy Mix
Consumption (per capita and in terms of units of GDP) and energy mix (domestic and foreign, primary and secondary, renewable versus non-renewable)
Energy Security in General
Energy security is achieved when there is an uninterrupted availability of energy at a national level and at an affordable price. All countries seek to achieve this; the most secure energy situation is where the national demand for energy can be completely satisfied by domestic sources. The more a country demands on imported energy, the more it is exposed to risks of an economic and geopolitical kind. Four key aspects of energy security are:
The importance of energy security stems from the fact that energy is vital to the functioning of a country. For example, it: powers most forms of transport, lights settlements, is used by some types of commercial agriculture; warms/cools homes and powers domestic appliances; is vital to modern communications; drives most forms of manufacturing.
- availability
- accessibility
- affordability - competitively priced energy supply
- reliability - uninterrupted
The importance of energy security stems from the fact that energy is vital to the functioning of a country. For example, it: powers most forms of transport, lights settlements, is used by some types of commercial agriculture; warms/cools homes and powers domestic appliances; is vital to modern communications; drives most forms of manufacturing.
Consumption
The consumption of energy is measured in two ways:
- in per capita terms, i.e. as kilogrammes of oil equivalent or megawatt hours per person. In general, this measure rises with economic development
- by a measure known as energy intensity, which is assessed by calculating the units of energy used per unit GDP. The fewer the units of energy, the more efficiently a country is using its energy supply. In general, energy intensity values decrease with economic development
The Energy Mix
The energy mix is the combination of different energy sources used to meet a country's total energy consumption. It's an important part of energy security, and varies from country to country. There are distinctions between:
How the energy mix has changed:
- domestic and foreign sources
- primary and secondary sources
- primary = found in nature, not converted/transformed. It can be renewable (water/wind/sunlight) or non-renewable (coal/oil/gas)
- secondary = derived from transformation of conversion of primary sources, usually more convenient (electricity)
How the energy mix has changed:
- 1820 - 20 exajoules, mainly biofuels (amount of biofuels remains constant until it rises slightly in the latter half of the 20th century). Very small amount of coal.
- 1900 - 50 exajoules - 30 coal, 20 biofuel .
- 1920 - 60 exajoules. Now some oil and tiny amounts of hydropower.
- A rapid increase takes place from 1940.
- 1960 - 120 exajoules. about 40 of which is oil. Small amounts of natural gas now being used.
- 1980 - 330 exajoules, increase in hydropower (about 10) and natural gas now at about 50 exajoules. Introduction of nuclear power.
- 2010 - 540 exajoules. About 40 biofuels, 150 coal, 190 oil, 110 natural gas, 20 hydro and 20 nuclear.
