Non-renewable energy (fossil fuels)
Introduction
Fossil fuels such as coal, oil and natural gas are non-renewable1 sources formed when pre-historic living things died and were gradually buried by layers of rock.
Producing and burning fossil fuels creates air pollution that harms our health and generates toxic emissions that drive climate change 2.
Coal
Coal is a fossil fuel primarily used for electricity generation and as a key ingredient in steel production. It is also used for heating and in various industrial processes.
Coal is formed from ancient plants that were buried and subjected to heat and pressure over millions of years, through a process called carbonization3. It exists in underground formations called coal beds. Coal beds exist on every continent, the largest coal reserves being in the United States, Russia, China, Australia, and India.
Coal can be extracted from the earth either by surface mining or underground mining. Once it has been extracted, it can be used directly (for heating and industrial processes) or to fuel power plants for electricity4. It is the world’s oldest and dirtiest industrial source of energy (Ritchie and Rosado, 2017).
According to Ritchie and Rosado (2017), the largest coal producers in 2023 were China (25,538.52 TWh5), India (6,105.90 TWh) and the United States (2,276.87 TWh).
Coal plays a crucial role in the energy mix6 of many developing countries, where it is viewed as a more affordable and reliable source of electricity. The electricity sector accounts for two-thirds of global coal demand. IEA7 reports that in 2023, coal consumption grew in both electricity generation and industrial sectors, with the iron and steel industry being the largest consumer. It continues being the largest source of global electricity generation globally with power generation from coal increasing by 1.9% in 2023 to 10,690 terawatt-hours (TWh).
Nevertheless, despite the rising demand for coal, it’s important to recognize its severely harmful effects on the environment. It is the most polluting energy source, both in terms of the amount of CO2 it produces per unit of energy and also the amount of local air pollution it creates. Moving away from coal energy is important for climate change and human health (Ritchie and Rosado, 2017). As a result, the EU is determined to increase the cost of CO2 emissions to operators which may eventually phase out coal based electricity generation, unless coal stations are fitted with Carbon Capture and Storage (CCS)89.
Oil
Petroleum (or crude oil) is a fossil fuel that is found in large quantities beneath the Earth’s surface. It is a smelly, yellow-to-black liquid and is usually found in underground areas called reservoirs. Oil exists in this underground formation as tiny droplets trapped inside the open spaces, called “pores,” inside rocks. The droplets cling to the rock, like drops of water cling to a window pane10.
The formation of oil started in the prehistoric oceans. Ancient plankton sank to the ocean floor after they died. Their tiny bodies were then covered with more debris as they drifted down from the surface and mixed with sand, silt, and rock. Heat and pressure from these layers transformed the remains into what we would recognize as petroleum or crude oil 11.
The main use of petroleum is gasoline, used as fuel in most cars. It is the dominant source of energy for the transport sector (Ritchie and Rosado, 2017). Petroleum is also used in making many products that we use on a daily basis. A majority of it is turned into an energy source. Other than gasoline, petroleum can be used to make heating oil, diesel fuel, jet fuel and propane.
In 2023, the top oil producing countries were the United States (9,620 TWh), Russia (6,300 TWh), Saudi Arabia (6,183 TWh), Canada (3,231 TWh), Iran (2,492 TWh), Iraq (2,478 TWh) and China (2,431 TWh) (Ritchie and Rosado, 2017).
Natural gas
Natural gas is now the second largest source of electricity production globally (Ritchie and Rosado, 2017). It produces fewer emissions than coal, hence many countries are substituting it for coal in their electricity mix.
Like oil, natural gas is found in rock formations deep beneath the Earth’s surface. Large drills are used to bore into the Earth and unlock natural gas from underground reservoirs. Pipelines then transport the fossil fuel to the end user. Natural gas is invisible, has no odor and is lighter than air.
In 2023, the top gas producers were United States (10,353 TWh), Russia (5,864 TWh), Iran (2,517 TWh) and China (2,343 TWh) (Ritchie and Rosado, 2017).
Fossil fuels have adverse effects on the environment, and hence there is a need to switch to cleaner energy sources. In the next post, we will explore the different types of renewable energy sources.
Next: Renewable energy
References
Footnotes
A non-renewable fuel is one that can run out because it takes a very long time to form. For example, oil and coal take millions of years to form deep underground. Once we use them, they are depleted and cannot be regenerated within a human lifetime, making them finite and limited.↩︎
Carbonization is the process of organic matter turning into carbon, usually under high temperatures and pressure.↩︎
Terawatt hours↩︎
The combination of the various sources used to meet energy needs in a given geographic region↩︎
A process of capturing the CO2 produced by power generation or industrial activity, such as hydrogen production, steel or cement making, transporting it via ship or in a pipeline and then injecting it into rock formations deep underground for permanent storage.↩︎