How Electric Energy Is Generated
Have you ever wondered how your mobile device and other electronic devices are charged? Besides keeping us digitally connected, electricity also saves lives in hospitals, powers industry and keeps the U.S. economy going. Whether it’s a 19th Century energy source like coal or 21st Century source like solar, it’s worth knowing how electric energy works, how it’s generated and where the juice that powers our lives comes from.
What You Need to Know About Electric Energy
Electric energy is created by the flow of electrons, often called “current,” through a conductor, such as a wire. The amount of electric energy created depends on the number of electrons flowing and the speed of the flow. Energy can either be potential or kinetic. A lump of coal, for example, represents potential energy that becomes kinetic when it is burned.
Common Forms of Energy
Here are the six most common forms of energy.
- Chemical energy. This is stored, or “potential,” energy. Releasing chemical energy from carbon-based fuels generally requires combustion like the burning of coal, oil, natural gas, or a biomass such as wood.
- Thermal energy. Typical sources of thermal energy include heat from underground hot springs, combustion of fossil fuels and biomass (as noted above) or industrial processes.
- Kinetic energy. Kinetic energy is movement, which occurs when water moves with tides or flows downstream, or when air moves wind turbines in the wind.
- Nuclear energy. This is the energy stored in the bonds inside of atoms and molecules. When nuclear energy is released, it can emit radioactivity and heat (thermal energy) as well.
- Solar energy. Energy radiates from the sun and the light rays can be captured with photovoltaics and semiconductors. Mirrors can be used to concentrate the power. The sun’s heat is also a thermal source.
- Rotational energy. This is the energy derived from spinning, typically produced by mechanical devices such as flywheels.
How Energy Sources Compare
There’s a lot of talk about good and bad energy sources and how (or if) they contribute to climate change. Before you become a part of the conversation, here’s a look at how energy sources stack up in the U.S. according to the Institute for Energy Research (IER).
- Fossil fuels 67% (coal 41%), oil (5.1%), natural gas (21%)
- Renewable energy 16% (mainly hydroelectric (92%), wind (6%), geothermal (1%), and solar (1%)
- Nuclear power 13%
- Other sources 3% (i.e., biofuels and biomass)