Are you reading this on your computer? Maybe your phone? Do you plug your devices in to charge every night, trusting that in the morning, it will be juiced to the max? Though we rely on it for most everything, most of us have no idea what electricity is, let alone how it is made. In this issue we’ll be talking about what energy is in the first place or, more specifically, electricity and how it finds its way into your life!
While Americans are accustomed to the ease of our modern electric system, there is a lot that goes into electrifying our homes and devices. Electricity is a secondary source of energy that is created by harnessing other primary sources of energy including coal, natural gas, oil, nuclear power, and other renewable sources like hydropower and wind (How Is Electricity Made? | How Does Electricity Work?). In the United States, most electricity is produced using turbine generators. These turn rotor blades to create an electric current that is delivered to our cities, buildings and homes.
The use of turbines and generators to create electricity is based on Faraday's Laws. In 1831, Michael Faraday discovered that by changing the magnetic field surrounding a wire, you can induce an electrical current within that wire.(How Electricity Is Generated - U.S. Energy Information Administration (EIA)) This discovery led to the creation of electromagnetic generators, which have since inspired the creation of the popular turbine driven generators that are the dominant form in the United States. Electricity is produced by these turbines when the blades spin to create a constantly changing electromagnetic field. This electromagnetic field then triggers the flow of electrons within the generator’s wires creating the current that will eventually find its way to your home’s appliances. More generally, this process converts the rotational kinetic energy of the turbine blades into electrical energy (How Electricity Is Generated - U.S. Energy Information Administration (EIA)
Before turbine blades can rotate, they first need a source of primary energy. In traditional power plants, this primary energy source comes mostly from coal, oil, natural gas and nuclear reactions. Except for nuclear, these sources must be burned to release their energy (as well as harmful byproducts including Carbon Dioxide). At a nuclear plant, a continuous nuclear reaction is maintained to produce the desired high temperatures. The energy is then used to create high pressure steam which gets directed through the turbine at the required pressure to rotate the blades. This process is not very energy efficient, as you know if you’ve ever tried to watch water boil, and even the highest efficiency coal plants fail to convert more than 40% of coal’s potential energy to electricity (DiPietro and Krulla).
Once the electricity is created it needs to be sent to our homes via the power grid, which “is the interconnected group of power lines and associated equipment for moving electric energy at high voltage between points of supply and points at which it is delivered…”(How Is Electricity Made? | How Does Electricity Work?). Power lines that we so often see along highways and byways are able to carry a high voltage of electricity. The higher the voltage, the less electricity is lost in transit, since there is an innate current resistance that creates heat, and thus, electricity loss (Terhune). To be safely used in our homes, electricity moves through a series of transformers, which lower the electricity voltage to a safe level for everyday use. In the United States, all electricity for a general power outlet is stepped down to 120 volts. In Europe, electricity is only stepped down to 220 volts, which is why you need to make sure to bring a converter for your hair dryer or you risk frying it.
The most simplified breakdown of all of this is:
(2) Simplified journey of electricity from a power plant to your home.
I hope this breakdown has illuminated (haha) the inner workings of how electricity and our electrical system works for you. While it can at times be a little hard to follow, having this foundation is going to be really helpful as we move forward and dive into the ins-and-outs of the different types of renewable energy.
Bibliography
How Electricity Is Generated - U.S. Energy Information Administration (EIA). https://www.eia.gov/energyexplained/electricity/how-electricity-is-generated.php. Accessed 10 May 2021.
How Is Electricity Made? | How Does Electricity Work? https://justenergy.com/learning-center/electricity/. Accessed 9 May 2021.
Terhune, Lea. “What Is the Power Grid and How Does It Work?” ShareAmerica, 18 Nov. 2016, https://share.america.gov/what-is-power-grid-and-how-does-it-work/.
DiPietro, Phil, and Katrina Krulla. Improving the Efficiency of Coal-Fired Power Plants for Near Term Greenhouse Gas Emissions Reductions. 16 April 2010. National Energy Technology Laboratory, U.S.Department of Energy, http://www.circleofblue.org/wp-content/uploads/2011/03/DOE-NETL-Coal-fired-energy-efficiency.pdf. Accessed 2021.
Image sources
How Electricity Is Generated - U.S. Energy Information Administration (EIA). https://www.eia.gov/energyexplained/electricity/how-electricity-is-generated.php. Accessed 10 May 2021.
“How Power Grids Work.” HowStuffWorks, 1 Apr. 2000, https://science.howstuffworks.com/environmental/energy/power.htm.
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