Electricity is the flow of electrical power or charge. It is a secondary energy source because it is converted from another (primary) source of energy, such as coal, natural gas, oil, nuclear or renewable sources. Electricity can be made from either renewable or non-renewable energy sources, but it is neither renewable nor non-renewable since it […]
Category: Energy
Energy is the capacity of a physical system to do work. The common symbol for energy is the uppercase letter E.
What is hydrogen
Hydrogen is the simplest and lightest element known to exist, with only one proton and one electron per atom. It is an energy carrier, not an energy source—it must be produced from compounds that contain it. It is the most abundant element in the universe and is the source of the energy we receive from […]
What is geothermal energy
Geothermal energy comes from the heat stored in the Earth’s core, about 4,000 miles/ 1,609 kilometers below the surface, and heat from the sun warming the Earth. The word geothermal originates from the Greek words geo (earth) and therme (heat). The ground is a good insulator and stores the heat as energy. Pipes are run […]
What is solar energy
Solar energy is the radiant energy (light or heat) that comes from the sun. Only a small amount of the sun’s energy strikes the Earth, one part per 2 million. But even that one part is an enormous amount of energy. Solar energy is the most abundant energy source available. In fact, according to National […]
What is hydropower
Hydropower is the energy captured from moving water. It is often used to make electricity, usually at dams. A renewable energy source, hydropower produced 6% of the United States’ total electricity and 67% of generation from renewables in 2008. Hydropower produces about 20% of the electricity used worldwide, according to the US Energy Information Administration. […]
What is nuclear energy
Nuclear energy is energy in the nucleus, or core, of an atom. Atoms are tiny particles that make up every object in the universe. Bonds that hold atoms together contain large amounts of energy that is released in the form of heat in two ways: nuclear fusion and nuclear fission. How Nuclear Energy is Formed […]
What is wind energy
Wind energy is the process by which the wind is used to generate mechanical power or electricity. People have been using energy from the wind for hundreds of years to pump water or grind grain. Today, we use a wind turbines to generate electricity. Wind power has a relatively high output, but only a fraction […]
What is coal
Coal is a nonrenewable energy source because it takes millions of years to create. It is a combustible black or brownish-black sedimentary rock composed mostly of carbon and hydrocarbons—molecules containing hydrogen and carbon. The energy in coal comes from the remains of prehistoric plants and animals, making it part of the fossil fuels family. How […]
What is Energy
Energy is the capacity of a physical system to do work. The common symbol for energy is the uppercase letter E. The standard unit is the joule, symbolized by J. One joule (1 J) is the energy resulting from the equivalent of one newton (1 N) of force acting over one meter (1 m) of displacement. There are two main forms of […]
What is petroleum
Petroleum (also known as crude oil or simply oil) is a fossil fuel that was formed from the remains of ancient marine organisms. Millions of years ago, algae and plants lived in shallow seas. After dying and sinking to the seafloor, the organic material mixed with other sediments and was buried. Over millions of years […]