Many of us use electricity every day, but few of us ever think about where it comes from. To most people, the fact that it just works is good enough, and they don’t really care how it happens. However, in this article, we’ll explain exactly how electricity is generated so you can be sure you understand the concept on an intellectual level as well as an intuitive one.
How Much Energy Do We Consume?
In 2015, US citizens consumed an average of 97 billion kilowatt-hours of electricity, according to figures released by Energy Information Administration. That’s a lot! Knowing how much energy we use can be important when considering how much energy it takes to generate that power.
And because power plants are in constant competition with one another, understanding where your power comes from can help you find better providers. Below, we’ll cover some general energy consumption numbers so you know what to expect from your home or business’s monthly utility bill.
What Are Fossil Fuels?
Fossil fuels are hydrocarbon deposits of natural gas, coal, and oil that have been formed from decaying organic matter. They’re often burned as fuel to produce heat and electricity.
Fossil fuels are only a small part of renewable energy sources—but they play an outsize role in supplying energy for electricity generation (especially coal) and transportation (particularly oil).
In 2017, about 80 percent of global primary energy production came from fossil fuels. Renewable energy sources made up about 18 percent; nuclear energy accounted for 6 percent; and other sources like geothermal made up 1 percent.
What Is an Alternating Current (AC)?
Alternating current, or AC, describes electricity that reverses direction at regular intervals. In America, we use 60-cycle alternating current; in Europe and elsewhere, it’s 50 cycles.
This means that every second, a regular house current goes from positive to negative to positive and back again—but not all at once; it takes 60 (or 50) seconds for one cycle. We measure the strength of an electric current in amps, which stands for amperes.
An amp can be thought of as how much water flows through a pipe in one second if the pipe is full. If you divide the amount of water flowing by the time it takes to flow through the pipe, you get its capacity measured in gallons per minute. With this system, there are 600 amps of capacity in a 60-amp current;
Nuclear Power
It's all about steam. Nuclear power plants use heat from radioactive material to boil water, creating steam that turns turbines and generates electricity. No smoke or moving parts in sight! For a deeper look at how these plants work, check out our full writeup on How Nuclear Power Works.
In nuclear reactors, fuel rods are placed inside a long tube of heavy metal called the pressure vessel. To make the reaction go, engineers bring in coolant, also known as coolant water (aka light or heavy water), which boils when it comes into contact with the hot fuel rods.
As it evaporates (turns into vapor), it creates pressure against the walls of the pressure vessel. Then they introduce control rods into the reactor core where they absorb some of this heat and slow down neutrons which helps keep an even balance between fissioning atoms - otherwise you could have another Chernobyl situation on your hands.
The History of Solar Power
Before electricity became a commodity, it was considered a luxury. An expensive luxury that only the rich could afford. Ancient Romans, for example, relied on slaves to crank their water-powered millstones to grind grain into flour and then used slaves’ oil lamps at night.
Over time (and with some technological innovation), electricity became much more affordable—and let’s be honest, who doesn’t like lights and air conditioning? If you want to understand how electricity works, it all starts with magnetism.
Hydropower (Water)
Water power is one of the most common sources of electricity generation. Water used in hydroelectric power stations flows through a dam, creating potential energy that can be used to turn turbines and generate electricity.
Water that flows into a hydroelectric plant from rivers or reservoirs must be high enough to produce sufficient flow for generating electricity. If a river or reservoir drops below its minimum level, water stops flowing through turbines and no electricity is generated.
Wind Energy
Wind power has been used for hundreds of years, although it wasn’t until around 1900 that we started to harness its energy on a large scale. Wind power is cost-effective, clean and renewable; but unfortunately, it isn’t widely available in many areas.
That said, wind energy can be an ideal supplement to traditional sources of electricity as you can use it as a source of primary energy or when wind conditions are favorable.
With support from government subsidies and incentives for consumers, wind power may soon be one of our most reliable sources of sustainable energy.
Geothermal Energy
In some parts of Iceland, geothermal energy accounts for as much as 25% of electricity generation. This type of electricity production has been going on in Iceland since 1970.
Geothermal energy taps into underground reservoirs of steam and hot water and uses it to produce electricity. Similar systems are in place in many other places around the world like California, Hawaii, Japan, Mexico, Italy and New Zealand.
However, not all areas are suitable for geothermal exploitation because they must be located near tectonic plate boundaries where magma is being pushed up from deep within Earth's mantle; areas with active volcanoes are also good spots to look for such power sources.
Sustainable Energy - Renewable Energy Resources (Green Power)
We tend to think of energy as being something that comes from a bottle or can in a store, but energy doesn’t come from a tank—it’s all around us. Energy and electricity are terms used interchangeably, although technically, electricity is only one type of energy source. How electricity is generated depends on what kind of renewable resources are available in your area.
Natural sources like wind, water and sunlight convert naturally occurring elements like hydrogen and oxygen into usable electrical power (in some cases they directly generate power while in others they just make generators more efficient).
While solar cells do have some drawbacks (they're still expensive), they have several benefits including cost-effectiveness, modularity and recyclability.