January 20, 2018 Energy Written by Greentumble Editorial Team
Types of nonrenewable energy sources
Energy security is an issue of ever

increasing global importance. We are so dependent on energy that continuous access to it is a prerequisite for the functioning of our economy and society. The supply of energy, heavily informed by geography and the natural resource wealth of countries, helps determine at least partly relations with other countries.

For example, who can forget the natural gas crises that spanned between 2009-2014, which culminated when Russia effectively stopped supplying natural gas to the Ukraine, which in turn meant that a lot of European countries no longer had access to natural gas [1].

The availability of affordable energy is the key issue of modern politics. In this context, one thing that is certainly worth highlighting is the fact that these energy concerns come into play almost exclusively when we are talking about non-renewable forms of energy. While a lot of countries may not have coal, oil, natural gas or uranium deposits, they definitely can benefit from wind, solar, geothermal or hydro power or a combination of thereof.

But the use of non-renewable energy affects our daily life in ways beyond relations with other countries – it has impacts on our health and environment, but it also has implications for the long-term sustainability of our economies.

So, it is worth looking into what are the four main types of non-renewable energy. This might help shed some light as to why we are still using primarily non-renewable resources today despite the proven potential of other technologies.

What are the four main sources of non-renewable energy?


#1 Coal

Coal is a black rock that can be burned to produce energy. Coal is made from fossilized plants. It is ranked depending on how much “carbonization” it has gone through: peat is the lowest rank of coal as it has gone through the least amount of carbonization, whereas anthracite is the highest rank of coal.

The history of coal mining goes back thousands of years, back to ancient China and Rome. However, it became crucially important during the Industrial Revolution in the 19th and 20th centuries, when it was primarily used to power steam engines, heat buildings and generate electricity. In many ways, the use of coal as a source of power was what enabled the Industrial Revolution.

Despite the fact that coal has been used for so long, it continues to be relatively abundant and cheap to convert to energy. However, coal extraction and combustion are both environmentally hazardous processes which carry with them a number of health concerns. Coal mining, especially surface mining, can be particularly destructive of landscapes and pollute local resources such as water and soil.

What is more, air pollution from coal-fired power plants releases sulfur dioxide, nitrogen oxides, particulate matter and heavy metals. These emissions create a number of dangerous environmental problems such as smog and acid rain, as well as numerous health risks for us, ranging from the diseases of the respiratory tract, cardiovascular, and cerebrovascular system [4]. In addition, coal is also an emitter of CO2 which contributes to climate change.

While some countries such as the UK have set a date of phasing out coal-fired plants, coal remains a key source of energy around the world.

Globally in 2013 we used 7,876 metric tonnes of coal, this was a 70% increase from 2000 [7].

For example, in the United States, 39% of the country’s electricity was produced with coal [5]. To put this in perspective, your average coal train is 2.4 kilometres long and yet it carries barely a day’s fuel for a large power plant [2].

Burning coal

Burning coal


#2 Oil

Another form of non-renewable energy is oil, a very versatile liquid fossil fuel that can be used for energy generation as well as a wide range of other applications. It is usually stored deep beneath the earth’s surface. Oil is extracted by drilling into where it is trapped between 2 layers of rock, a pipe is then inserted in the hole to siphon it to the surface.

When the so-called drill rigs are set up, either onshore or offshore, oil can be extracted 24/7 for several decades. Once the oil has been drilled, it must be refined to separate it from several other chemicals.

When it is refined around 45 gallons of petroleum products are created through refinery processing gain. The products created are gasoline, ultra-low sulfur distillate, jet fuel, hydrocarbon gas liquids, heavy fuel oil and heating oil.

The advantages of oil are that it is the fuel that has made modern transportation possible, it is relatively cheap to produce and use. About half of the world’s petroleum is converted into gasoline used to fuel our cars. The rest can be processed and used in liquid products such as nail polish and rubbing alcohol, or solid products such as water pipes, shoes, crayons, roofing, vitamin capsules, and thousands of other items. Combined with other chemicals oil provides the basis of both rigid and flexible plastic as well as a number of solvents [2].

The world used 35 billion barrels of oil in 2016 [8].

While oil’s versatility is impressive, there are environmental risks that come with extracting oil and using it. One very important consideration is the risk of spills as oil can destroy local habitats and kill animals. Some of the most renowned environmental disasters are linked to oil spills – for example, the Exxon Valdez and BP Deepwater Horizon oil spill. 

Oil’s environmental and health impacts are similar to those of coal, particularly when it comes to air pollution and climate change.

Spilled oil

Spilled oil

If you would like to know more, continue reading Why Is Oil a Non-renewable Resource.


#3 Natural gas

Natural gas is is the second most abundant non-renewable energy source. While coal is a rock and oil is a liquid, natural gas is – as the name suggests – a gas. Natural gas is predominantly methane. It was formed like the other fossil fuels with pressure and heat pressing on organic material over millions of years. Unlike oil and coal deposits, natural gas is not found in big open pockets but rather trapped in rock formations [2].

The process of extraction, called hydraulic fracturing, is slightly more complicated. It involves high-pressure water being piped underground to break the rock and release the gas. If the rock is too hard, chemicals are used to dissolve the rocks.

When natural gas is initially extracted from the ground, we get “wet natural gas” because it usually contains liquid hydrocarbons and non-hydrocarbon gases. To separate methane and other useful gases from the wet natural gas, it has to be processed.

The total amount of natural gas consumed in the world in 2010 was 113 trillion cubic feet [9].

The biggest advantage of natural gas is the affordability of this source of energy – that’s what allows its widespread use for heating and cooking.

Compared to coal and oil, natural gas emits a lot less CO2. From this point of view, it is better for our environment. The other substance released is water vapor, which is nowhere near the hazardous air pollutants emitted by the oil and coal industry.

At the same time, natural gas is primarily made up of methane, another greenhouse gas, which is far more potent than CO2. This means that using and transporting natural gas could potentially release large amounts of methane into the atmosphere, which can have disastrous implications for the planet’s climate.

While natural gas is considered the cleanest of fossil fuels, its extraction is problematic. Hydraulic fracturing can create mini-earthquakes and the use of chemicals can contaminate nearby soil and water resources. Mini-earthquakes can be particularly damaging to local communities particularly in terms of the value of their houses and property.

Burning natural gas for cooking

Burning natural gas for cooking


#4 Nuclear power

Nuclear power is not a fossil fuel but it is a non-renewable form of energy. Nuclear power is considered non-renewable because the material used in nuclear power plants – uranium – is a non-renewable resource [2].

Nuclear energy is generated from the energy released when atoms of uranium are split during the process of nuclear fission in a nuclear reactor. The type of uranium used for nuclear energy is U-235. This uranium isotope is used because its atoms are easily split apart.

Uranium is a common metal found in rocks worldwide, but nuclear energy needs uranium 235 for nuclear fission. Uranium is extracted from rock and then enriched to become uranium 235 isotope before being made into pellets that are loaded into assemblies of nuclear fuel rods.

The great advantage of nuclear energy is that nuclear power plants do not pollute the air or emit greenhouse gases. Small amount of radioactive material produces a lot of energy, the raw materials are relatively cheap and last a long time.

Having said that, not only are U-235 reserves limited but extracting uranium, as well as disposing of the waste generated from the production of nuclear energy can be damaging to the environment. The radioactive material is dangerous and any accidents can be particularly costly to both the environment and our health.

Working towers of a nuclear power plant

Working towers of a nuclear power plant



[1] http://www.bbc.co.uk/news/world-europe-29521564
[2] http://www.nationalgeographic.org/encyclopedia/non-renewable-energy/
[3] http://environment.nationalgeographic.com/environment/global-warming/high-cost-coal/
[4] http://www.sourcewatch.org/index.php/Environmental_impacts_of_coal
[5] https://en.wikipedia.org/wiki/Coal_power_in_the_United_States
[6] https://goo.gl/nYoomG
[7] https://www.iea.org/about/faqs/coal/
[8] https:// www.iea.org/about/faqs/oil/
[9] http://www.nationalgeographic.org/encyclopedia/non-renewable-energy/