Build a Generator

Let’s start with first principles. Generating electricity from motion is a simple matter of physics. If you move a magnet past a conducting metal, it will generate a current. As this video shows, dropping an iron magnet down a copper pipe creates a mysterious force that slows its fall.

This is a classic example of a counterintuitive, experimental result leading to a scientific breakthrough. Michael Faraday built the world’s first electrical generator exactly this way — moving a magnet back and forth through a coil of copper, inducing an electromagnetic current. Modern generators are pretty much just more efficient versions of this device.

It works in reverse, too. A motor operates by generating a force when a current is passed through a stationary conductor inside a magnetic field. And building one of those is easy. All it takes is a magnet, a piece of wire, and a battery.

So, really, that’s it — generating your own power is as simple as spinning a magnet near a coil of copper.

Once that’s set up, though, you’ll need to figure out what’s going to make that magnet spin. You could hook it up to a bike, for example, but I wouldn’t recommend it. It makes bedtime reading desperately tiring.

Turbines

The vast majority of the electricity generated by mankind comes from turbines — devices that turn the flow of something (like air or steam) into rotational movement. A 20th-century nuclear plant might seem unrelated to a water wheel attached to a centuries-old country mill, but they’re pretty much working off the same engineering principles.

A wind turbine is probably the easiest to build at home. You can rig one up using plastic bottles for blades.

Or maybe you’ve got some old AOL trial CDs still lying around. (What? They’re collectibles!) They work just as well as waterwheels, if that’s your bag.

Solar Heating

Alternatively, you can join the solar power game — and why wouldn’t you want to? Solar is growing at an astonishing rate, and is well on the way to becoming the world’s largest single source of electricity by 2050, according to the International Energy Agency.

The simplest way to turn sunlight into energy is by concentrating the light rays, either through a lens (think of a magnifying glass being used to torture ants) or by using a curved, mirrored trough. The key is to capture a broad patch of sunlight and focus it into a tiny area. You can see that happening in this clip, where YouTuber Grant Thompson creates a focusing monster capable of heating objects up to 2,000° Fahrenheit [1,093° Celsius].

If you take that beam of light and focus it on a vessel containing water, it’ll boil — and that steam can be passed through the blades of a turbine, spinning it around to generate electricity. Easy.

That said, if you want to skip the make-it-yourself part, there’s a company called Rawlemon that produces small desktop phone chargers based on exactly this principle.

Photovoltaics

There is another way to exploit the sun directly for power. Most solar electricity comes from photovoltaic cells — they’re the things that make up the solar panels on buildings across the world. They work by directly converting sunlight into current through the ionization of certain crystals, made of silicon and other minerals.

Building a solar panel at home is actually possible, even if you don’t want to deal with messy chemicals and poisonous fumes. (I’m assuming that you don’t, but hey, I don’t judge.) Really, all you have to do is cook a plate of copper on a stovetop for about half an hour, like in the following video, until it forms a black layer of oxides. Let it cool for a bit and the black layer will peel off, leaving an exposed layer of red cuprous oxide.

Once you’ve got your oxidized copper, you can dip it into some salt water opposite an unoxidized piece to build what is, effectively, a very simple battery with two electrodes (the plates) and an electrolyte (the salt water). The difference in charge between the electrodes causes a tiny electrical current to be generated. Sunlight hitting the red cuprous oxide gives some electrons enough of a kick to escape the plate and head into the water, starting a trip around the circuit, though this setup will generate a slight charge even in the dark. It’s not very efficient, which is why we don’t use cuprous oxide for solar panels, but it works.

Fruits and Vegetables

Another alternative to a solar cell is plants. Leaves are able to convert between three and six percent of the light they receive into stored chemical energy; and, as most school kids know, you can extract that energy as electricity by sticking metal electrodes of two different types (usually one copper and one zinc) into pieces of fruit or a potato connected to a circuit.

An individual potato or lemon is a poor battery; it can illuminate a low-power lightbulb for a brief period, but that’s about the limit. Connect up a lot of them, however, and you can actually generate enough power to charge a phone.

Artist Caleb Charland ran an experiment in a British mall in July 2014 with 800 potatoes and apples hooked up to a wireless charging pad as part of a Nokia ad campaign — and it apparently worked, generating an average of six volts and 20 milliamps.

(Note: It is not possible to charge a phone by plugging a USB cable into a lone piece of fruit or potato, no matter what you might have seen elsewhere on the web. Not only is a single bit of produce unable to provide enough power on its own, that’s just not how USB cables work. Electronics isn’t magic, and you need two different types of metal for power generation to occur. The energy doesn’t just appear from the fruit into the cable — it comes from the reaction between the acidic liquid inside the fruit and the metals.)

Fireworks

Finally, maybe you just want to watch the world burn — like YouTuber Colin Furze, who built a giant firework-powered wheel, because … well, why not?

This takes us back to first principles — it’s all about finding something that moves, and converting the energy of that movement into energy. Furze’s fireworks wheel is just for show, but you could just as easily attach fireworks to a turbine to make more efficient use of all that explosive power. (And what’s more fun than energy-efficient fun?)

You could use an endless number of things other than fireworks — a dog on a treadmill; water falling through a gutter; or a parrot carrying some magnets, flying through a carefully constructed racecourse of copper coils.

What would you choose? (And do wear goggles for whatever you create, please.)