One way or another, most of our electricity comes from solar energy

get it? So the rotating ring produces an oscillating flow; If you graphed their values ​​you would draw a sine wave. This creates an oscillating voltage in the wire, causing the electrons to move, and boom: you have alternating current. You’ve just created a generator! This is called electrical induction.

You can now enhance this by replacing that single loop of wire with a coiled coil containing many, many loops. Oh, it also works in reverse: instead of rotating a coil in a fixed magnetic field, you rotate a magnet around a fixed coil. Relative motion is all that matters.

Put a spin on it

As you can see, almost all methods of generating electrical energy boil down to magnets and a coil of wire. We just need a way to rotate one or the other. So we have some options. If you put large blades on your rotor and expose it to the wind, the collision of air molecules on the blades generates torque and turns the shaft. These are wind turbines. Or you can put turbines in a large dam and use the flowing water to power them, that’s hydroelectric power.

You can also boil water and use the steam to drive turbines. This is what most power plants do, in fact, usually by burning fossil fuels to bring in heat. It could be coal, oil, or natural gas, it’s all the same technology. Or you can tap into geothermal heat and use it to produce steam, yes, that is geothermal energy.

In fact, that’s how nuclear power works too: you take a heavy element like uranium and break it down into smaller atoms, giving you the energy to heat water and run steam turbines. Yes, the only difference between a coal-fired power plant and a nuclear power plant is how the water is boiled. You think it’s more complicated, right?

But again, there is a major exception, which is generation technology that does not use induction. Did you notice the omission? Ironically, it’s solar panels. Photovoltaics are solid-state devices – with no moving parts – that convert light directly into electricity.

Directly from the source

How much juice can we get directly from the sun? Well, the intensity of solar radiation decreases as it moves away from the Sun, because a certain amount of light is spread over a larger area. When it reaches Earth, some of that light is absorbed or scattered into the atmosphere. (That’s why the sky is blue.) But we’re at a sort of ideal distance, a distance that keeps the oceans from boiling or freezing.

At the equator, solar flux — the amount of energy reaching Earth — is about 1,000 watts per square meter. Of course, the Earth is curved, so it descends as it moves toward the poles. But in a good place, with a panel with a 20 percent conversion efficiency, you can get up to 200 W/m². This means that it only takes a few panels to supply all of a home’s electricity needs.

So, yes, most of the energy we use comes from the sun. You might also think of fossil fuel deposits as batteries, storing solar energy for future civilizations. But with older technologies, we get that energy indirectly, after multiple conversions from one form to another, and inevitable losses along the way. Why not cut out the middlemen and go direct? There are no carbon emissions, no air pollution, no radioactive waste, and no mining or transportation costs. The sun will continue to shine for 5 billion years.