Non-renewable energy sources are energy sources that tend to be depleted over time, and therefore the environmental impact associated with their exploitation is generally greater than that of renewable energy sources, which instead are naturally replenished in a relatively short period of time. It cannot be produced, grown, or generated on a scale which can sustain how quickly it is being consumed. Once it is used up, there is no more available for the future.
Non-renewable energy sources are often exploited by mankind because they can produce the highest amounts of energy with technologically simple and proven systems. The use of such sources is often associated with environmental problems such as the production of greenhouse gases or radioactive waste. The four main non-renewable energy sources are:
- Crude oil (petroleum)
- Natural gas
- Uranium or plutonium (nuclear energy)
All fossil fuels are nonrenewable, but not all nonrenewable energy sources are fossil fuels; coal, crude oil, and natural gas are all considered fossil fuels because they were formed from the buried remains of plants and animals that lived millions of years ago. Uranium ore, a solid, is mined and converted to a fuel used at nuclear power plants. Uranium is not a fossil fuel, but it is classified as a nonrenewable fuel.
Non-renewable energies, or more properly non-renewable energy sources, also simply called non-renewable sources, are energy sources that have been generated in nature in the order of millions of years in the case of fossil fuels, or before the formation of the planet Earth in the case of fissile materials (uranium and plutonium), as opposed to renewable energies, which are naturally replenished in a relatively short period of time; for this reason, once they are finished, non-renewable sources will not be available again on the human scale of time.
Most non-renewable energy resources are concentrated in a limited number of areas on Earth, which can lead to geopolitical and military issues, unlike renewable resources, which are primarily distributed over large geographic areas. Reducing the use of non-renewable sources, implementing renewable energy, and increasing energy efficiency results in climate change mitigation and subsequent economic benefits.
Since the early 1900s, mankind has consumed more primary energy from non-renewable sources (fossil fuels) than from renewable sources (at that time wood, animal energy, hydraulic and wind power) because fossil fuels, at equal weight, were able to produce greater amounts of energy than wood, in addition to the fact that deforestation had become unsustainable. Through the industrial revolutions, these energy sources have allowed the improvement of human living conditions.
Currently, non-renewable resources are technologically preferred because, once extracted, they are easy to transport, have a high energy density, and produce energy when needed with technologically simple and proven facilities, which has resulted in the consolidation of fossil industries at the center of the world economic system; However, the use of these sources brings with it some environmental problems such as the emission of greenhouse gases for fossil fuels or the disposal of radioactive waste for nuclear fission; for these and other reasons, the environmental impact associated with the fossil fuel cycle is generally greater than that of renewable energy sources.