Nuclear Energy Vs. Fossil Fuel

by Debashree Sen; Updated September 26, 2017

Nuclear energy is the energy stored in the nucleus (core) of an atom. This energy is released through fission (splitting atoms) or fusion (merging of atoms to form a larger atom). The energy released can be used to generate electricity. Fossil fuels—which mainly include coal, oil and natural gas—provide the majority of energy needs around the globe. Generation of electricity is one of the predominant uses of fossil fuels.

Electricity Generation

Nuclear energy is created by splitting a uranium atom. The nucleus of an atom is made of protons and neutrons and is surrounded by electrons. When the atom splits, it releases energy in the form of heat. Some neutrons are also released in the split. These neutrons might split other nuclei, releasing more heat and neutrons. This chain reaction is called nuclear fission.

Fossil fuels were formed from the organic remains of prehistoric plants and animals. These remains, which are millions of years old, were converted by heat and pressure in the earth's crust into carbon-containing fuels.

Both nuclear and fossil fuel power plants produce electricity the same way. The heat generated in these plants is used to generate steam. This steam drives a turbine, which powers a generator that converts mechanical energy to electrical energy.


Nuclear energy is cleaner while generating electricity. Nuclear fission provides energy without releasing greenhouse gases such as carbon dioxide. However, nuclear power plants generate significant amounts of radioactive waste.

Combustion of fossil fuels releases carbon dioxide into the atmosphere. According to the Massachusetts Institute of Technology, 90 percent of the carbon emissions from electricity generation in the United States come from coal-fired power plants. They emit pollutants such as sulfur dioxide, toxic metals, arsenic, cadmium and mercury.


According to Ewan McLeish in "The Pros and Cons of Nuclear Power," a pellet of nuclear fuel weighs approximately 0.1 ounce (6 grams). However, it can yield the amount of energy equivalent to that generated by a metric tonne of coal, which makes it much more efficient.


Uranium is one of the most abundant energy sources on Earth. According to John Giacobello in "Nuclear Power of the Future," uranium can be reprocessed and used again. Fossil fuels, on the other hand, are non-renewable. There has been a steep decline in the energy reserves because of our dependence on them.


According to Giacobello, it takes 1.92 cents to produce one kilowatt-hour of nuclear power. For coal powered plants, it takes 1.88 cents; for natural gas power plants, it takes 2.68 cents; and for oil powered power plants, it takes 3.77 cents to generate the same amount of power.


Fossil fuel sources are gradually depleting, thus it might lead to an impending global scarcity of energy. According to McLeish, "nuclear energy is not dependent on external energy sources. Thus, it can be a viable source of generating electricity in the future."


About the Author

Debashree Sen is a technical writer and has written for non-profit organizations. She has been regularly contributing to eHow since 2009. She is a member of the Society for Technical Communication (STC). She has a master's degrees in professional writing and English literature.

Photo Credits

  • nuclear power station 4 image by Vitezslav Halamka from