Non-Renewable Energy Sources (Fossil Fuels)

In this non-renewable energy sources (fossil fuels) post we have briefly explained about non-renewable energy sources like coal, natural gas, petroleum, and uranium.

Non-Renewable Energy Sources

These resources have formed over millions of years of geological processes, and we’re using them faster than they can be naturally replenished. Examples include fossil fuels like coal, petroleum, and natural gas.

We currently depend on non-renewables to meet most of our energy demands, extracting and combusting them primarily to generate electricity or develop fuels for transportation.

While we often consider nuclear power as an alternative energy option, it is important to remember that while its carbon output is very low compared to fossil fuels, nuclear fission is still a non-renewable resource.

Non-Renewable Energy Resources

Non-Renewable Energy Sources (Fossil Fuels)


A combustible sedimentary rock made up mostly of carbon and hydrocarbon, coal a non-renewable energy sources is the most abundantly used fossil fuel worldwide for the generation of electricity.

In the United States, approximately 93% of the coal consumed is used to generate electricity (EIA website). The steel, concrete, and paper industries also rely heavily on coal for both heat and by-products. The combustion of coal results in almost 3 times as many CO2 emissions as the amount of coal combusted.

Natural Gas

A gas one of the another important form of non-renewable energy sources that is made up mostly of methane and found near other fossil fuels, like coal. Methanogenic processes occurring in landfills and marshes also produce natural gas. Like petroleum, natural gas must first be processed before we can use it as a fuel. It is important to remove most of the other components of natural gas until it is almost purely methane.

When combusted, natural gas produces only about half the greenhouse gas emissions as coal does, making it a popular fossil fuel in our increasingly carbon-conscious society.


A toxic, flammable liquid non-renewable energy sources occurring in geologic formations beneath the earth’s surface (also known as crude oil). We use oil for a wide variety of things – the largest use of petroleum is for fuel oil and gasoline. But, you’ll find petroleum in places you might not expect it as well – pharmaceuticals, plastics, asphalt, kerosene, and synthetic rubber, to name a few. 

Like natural gas, petroleum must be processed before we can utilize it. Crude oil naturally contains many different types of hydrocarbons, all with different boiling points. So, to process the oil for a specific application, the crude must be heated to a specific temperature range.


A very heavy, fissile metal (U-235) an dangerous non-renewable energy sources  that can be caused to split in a fission chain reaction, producing tremendous quantities of heat which can then be used to generate electricity.

Because the reaction of one nucleus capturing another neutron sets off another 2-3 reactions, the resulting chain reaction is exponential and allows us to generate a substantial amount of heat with a relatively small amount of uranium.

After extraction, uranium must be processed before we can start the fission process. Most reactors utilize uranium that has been finely ground and then gasified to uranium hexafluoride which is then converted to pellets of uranium dioxide.

While nuclear power offers us a greenhouse gas emission-free source of energy, the concerns associated with reactor failure and long term storage of spent fuel present significant barriers to widespread adoption.

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