What Is Energy?


Energy is the fundamental building block of the universe. It enables everything to move. Specifically, a joule equals the amount of work done by one newton of force moving an object one meter. Another way to think about energy is the amount of force necessary to lift a small object against gravity. Or, in electricity terms, it equals the amount of energy necessary to move a single coulomb of charge through an electric potential difference of one volt.

Potential energy

In the study of matter, the term “potential energy” is used to describe energy stored in a system. The potential energy of a body depends on the location of its components, and is generally measured relative to a reference state. This reference state is infinitely far away from the system’s current state. Generally, the reference state is the centre of the earth, but it can also be sea level, a floor, or a tabletop. Potential energy differences between these locations are physically measurable.

Kinetic energy

We use kinetic energy in our everyday lives. The motion of a car turns kinetic energy into thermal energy, which is converted back into usable energy by the brakes. We also use kinetic energy to create electricity through an electric motor, and we turn wind and water into wind power. However, most kinetic energy sources are not very convenient to store and can lead to waste. To save these resources, you can turn to alternative energy sources.

Thermal energy

Thermal energy helps us understand how matter changes states. It changes the state of matter, allowing a substance to go from a solid to a liquid or from a gas to a solid. This process changes the internal energy of molecules and atoms. Here are some examples of thermal energy in action:

Nuclear energy

The reprocessing of spent reactor fuel is a method of reusing 90% of its volume as new fuel. Although it is costly and time-consuming, reprocessing is often preferred to producing new fuel from mined uranium. However, all reactors breed Plutonium-239, a material used in nuclear weapons. Reprocessing is controversial because of its potential proliferation risks. However, this method is still being used in France.

Chemical energy

The energy released in chemical reactions is equal to the difference in energy content between the reactants and the products. It can be estimated from the bond energies of the reactants, and calculated from the internal energy of the product molecules. Let’s explore some examples of chemical energy. For example, nitroglycerin absorbs energy from its surroundings to make a cold pack that helps athletes recover from intense workouts. Coal is the most well-known source of chemical energy, and it’s also used to generate electricity.

Wind power

The cost of wind energy is higher than any other alternative energy source, but it is also more environmentally friendly. Wind turbines are constructed hundreds of feet high and require underground power lines to transport the energy. This is because wind turbines produce a lot of noise. Additionally, the wind turbines also produce a lot of light, making them an excellent alternative energy source. Nevertheless, wind energy is not for everyone. In addition to its high cost, many people are reluctant to use wind energy as a primary source of energy, and there are some concerns regarding its safety and the quality of air quality.


Hydropower as an energy source is an important part of a country’s economic development. In addition to generating electricity, hydropower also serves as an energy bridge. Hydropower only provides a small percentage of the electricity needs of most countries, and coexistence with other energy sources is vital for environmental protection. The disfavor noted above, as well as the need for alternative sources of energy, are most apparent in hydropower’s reliance on rural and agricultural land uses.