The light comes on when you flip the switch. You know it’s not magic, but do you really know how electricity works?
Engineers around the world are using sophisticated technology to push the boundaries of how we use electricity, but the fundamentals of electricity are actually pretty simple.
What is Electricity?
Electricity is the flow of an electrical charge among atoms, and it’s been occurring in nature since long before the first power plant. Today, it’s one of the most commonly used sources of energy around the world.
Even if you don’t remember everything you learned in science class, you may recall the basic structure of an atom: protons and neutrons are clustered together in the center, with electrons spinning all around the outside. Most of the time, the positively charged protons use their opposing force to keep the negatively charged electrons close by. But with some elements — like copper, commonly used in electrical wiring — the outer electrons can be forced out and onto a nearby atom. This flow of electrons is how electricity occurs on an atomic level.
What is electricity used for? You name it — just about every technology and convenience of 150 years ago is now powered or enhanced by electricity. Light, climate control, entertainment, transportation, cooking, medical care — it’s hard to imagine how different our world would be if we didn’t have electricity at our fingertips.
How Is Electricity Generated and Transmitted?
Even though electricity occurs naturally, the form that we use is generated in power plants, which makes it a secondary source of energy. That means we must use another energy source to generate the electricity in the first place. That source can be fuel such as coal, natural gas or nuclear energy, or it can be a renewable source like solar or wind energy.
Within power plants, the fuel source is used to power massive turbines, which in turn power huge generators that convert that mechanical energy into electricity. From there, the electricity flows to a large transformer, which amplifies the voltage of the electrical charge.
This flow of electricity leaves the power plant along a series of high-voltage transmission lines, which lead to electrical substations. The substations reduce the electrical flow and transmit it along smaller power lines to another layer of transformers, which are the cylindrical devices you see connected to some utility poles. That’s where the voltage is reduced to its final, safe level and transmitted to homes and buildings along a final set of power lines.
What Stores Electricity?
A common misconception about the delivery of electricity is that electric companies can store electricity and distribute it later. That’s not accurate now, but it’s likely to become a larger part of the electrical distribution mix in the future.
In general, electrical utilities generate electricity on demand. When demand is high, they must fire up additional turbines, and when it’s low, they use fewer. But this can pose certain challenges, especially when it comes to renewable fuel sources like wind and solar. If the demand for electricity isn’t high enough when the sun is shining and the wind is blowing, some of that renewable energy may be lost.
However, there is a way to store energy for later: batteries. The batteries you put in a flashlight may just cost you a buck or two, but the batteries needed to store energy from solar and wind farms are much more expensive. For now, they’re not cost effective solutions for storing electricity on that sort of scale, but that’s expected to change over the next couple of decades.
In the meantime, homeowners who have solar panels or other sources of renewable energy at home can buy home-sized batteries to store energy when it’s free or cheap. But with costs of several thousand dollars including installation, even home batteries aren’t quite cost effective just yet.
As you can see, you don’t need to be Thomas Edison to understand the basics of how electricity works. And now that you do, you have one less thing to wonder about when you flip the switch.