Nuclear power appears to be a powerful way to make steam that spins a turbine. Same with geothermal, wind, & hydro. Maybe not solar? Isn’t energy lost in the multiple energy conversions (heat, water state, kinetic)? Is it theoretically possible to have a power source that more directly moves electrons through a circuit? If solar is the only one that can, it’s limited in efficiency and where it can be used. What about power generation undersea or on Ganymede or something?
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There are piezoelectric materials that generate electricity when vibrated. commercial ones are called “energy harvesters”. They have a cantilever structure that vibrates at a resonant frequency, and it produces electricity. The ones they have currently only produce small amounts of electricity, but they’ll keep a battery charged.
There are some power generators that use piezoelectricity, which is a charge that develops in some materials when subjected to mechanical stress. I don’t think there are any in commercial use for generating useful amounts of power yet, but those light up sneakers that used to be popular are an example of commercial use of a piezoelectric generator.
At the end of the day you’re taking mechanical energy and converting it to electrical. That’s what the generator does and that’s driven by a turbine. Even some types of solar are turbine driven (e.g. molten salt, any non PV source)
IIRC, those large generators are very optimized for reducing lost mechanical energy. I toured the Fermi power plant outside of Detroit when I was in college. We were standing next to one of the ginormous generators (like the size of a couple of buses) and the guy said they’re so finely balanced etc. that you can turn it by hand.
You’re right that there are only a few unique ways to generate electricity. That I can think of:
* Electro-mechanical: move a magnet along a wire
* Photovoltaic (solar): move electrons using kinetic photon energy from the sun (this is really just massively distant nuclear power)
* Thermoelectric effect : direct conversion of heat to electric current by applying the Seebeck/Peltier effects and Thomson effect
The last one might be new to you, but it is similar to photovoltaic in that it induces electron flow with no moving parts. It works on a similar principle to photovoltaic though, in that it uses semiconductor materials in its construction.
A device that converts heat to electricity in this way is called a thermoelectric generator or TEG. There is even a sub-type of TEG called an radioisotope thermoelectric generator (RTG) that uses the heat generated from nuclear decay to generate electrical power. This type of power source is used in satellites that cannot reliably use lithium-ion batteries & solar panels.
The reason we don’t use thermoelectric generators to power our homes is because of efficiency. TEGs are only about 5-8% efficient. By contrast, steam turbines routinely reach 40%.
So far, our best solution for converting heat energy to electrical energy is through a kinetic intermediary.
Plenty of other methods. I think it’s worth pointing that a turbine doesn’t generate electricity by itself. You can use a turbine to do any number of things. Such as turn a propellor on a ship.
To produce electricity you need to connect the output shaft of the turbine to a *Generator*.
You can also spin a generator from some other source of rotary motion such as a diesel engine. It’s common to use large diesels as a source of backup power during grid failures, for example. However since diesel is somewhat expensive and diesel engines have a lot of moving parts they’re not typically used for main grid power.
One commonly mentioned method in the news is Fuel Cells. These use hydrogen or other materials like ammonia or zinc, and oxygen in the air to generate an electrical current. They are a subset of batteries, however they are not rechargeable and require a continuous supply of reactants. The other downside is that hydrogen and ammonia aren’t widely available raw materials on earth, so such fuels must be produced synthetically. This always requires more energy input than you will get back out from the fuel cell later. So it’s generally cheaper to just send that electrical power over wires rather than adding extra steps.
Another method similarly to solar cells (technically Photovoltaic Cells) is Thermoelectric cells AKA Seebeck Cells. Typically these use semiconductor materials similar to PV cells. However instead of light being used to create a voltage, they use heat flow from a hot surface to a cold one.
However these are very inefficient so they’re not cost-effective for large-scale generation. They’re useful when you have a source of waste heat and want to gain a small amount of electricity to power some small electronic device. They’re also useful because they have no moving parts and have proved incredibly reliable. They’re sometimes used on spacecraft.
Another method is a linear alternator. These are pretty simple. They’re a cylindrical magnet inside a tube, surrounded by several coils of wire. The magnet can be made to reciprocate in some way. As the magnet passes a given set of coils the changing field induces a current in those coils. This can be converted into standard AC or DC using electronic switching devices.
These could potentially be attached directly to a piston or set of pistons mounted on a heavy spring, doing away with the crankshaft and connecting rods, thus increasing reliability of a piston-driven generator.
Another method is called thermionic conversion. This takes advantage of the tendency of electrons to “boil off” the surface of a material at high temperatures, in a vacuum. This is called *Thermionic Emission*. If a relatively cold metal plate is placed around the hot object the emitted electrons will collect on the plate. This produces a difference in voltage between the hot object and cold collector plate. This can be used to produce a significant current. Since this method requires a vacuum it’s mostly been used in space. Typically, the heat source is a radioactive isotope like strontium-90 or plutonium-238 with a relatively short half life.
You could also potentially heat a strip of tungsten metal with a special coating, using a large lens or mirror to concentrate sunlight on it, to produce electrons in the same way. So in space this method may be more efficient and reliable than solar cells.
Since it’s Eli5, and some of the other answers do the job, I’ll keep it simple and give you an example of energy that anyone can understand. From the example, you just apply the principle to energy production as a whole. What I’m writing doesn’t apply to dirty energy like coal or natural gas.. purely friction/natural collected energy.
*Potential* energy is all around you.. and *Kinetic* energy is what we get when potential energy is released. You can do an experiment right now as you read this with a pillow from your bed.
Grab the pillow and hold it out to your side adjacent to your body, that pillow is now in the Potential energy phase.. they call that potential energy because when you let go and it falls to the ground the potential energy is released into *kinetic* energy. That kinetic energy is the “falling” to keep it simple.
In an overly simplistic way, a wind turbine or dam will use this same principle. In the case of a dam, we build a containment wall that dams up the water into these massive pools. In those retaining walls we have these small (relative) openings with turbines in them that are connected to electrical grids and power stations. All that water dammed up with those openings closed is potential energy. When those openings go live and water goes through and spins the turbines it has now become kinetic. We then take that energy produced and channel it out it’s respective grid to where it needs to go.
That’s a good foundation to start with. But basically everything around you contains power in one way or another it’s just in different phases. Hope that helps. It’s a little splintered from your question, but like I said other answers did well enough so wanted to pepper in this grade school type example that anyone can get.
A big part of it is that the main way we know how to generate electricity is by varying a magnetic field when it is near a wire. This can be done by moving a magnet forward and backward through a coil or rotating the magnet with a coil around it and a few other ways. Rotating is much easier to do than alternating linear motion.
So generating electricity relies on finding a way to rotate the magnet at specific speeds to generate power at the correct frequency you want. The easiest and most efficient way to do that is usually to use a turbine to spin said generator.
I think it’s very sad that no matter how much we advance, all we are creating are better steams engines… I get hyped up about these new discoveries in nuclear energy and then find out “oh it just makes steam faster” and it’s all gone. Are we ever going to move beyond this method of obtaining energy?
You can generate electricity without spinning turbines, but it’s an efficient way to move the magnets in the coil to move the electrons. There are configurations of magnets that can generate electricity through rocking motions and even movement of the ocean, but because the motion is not continuous, the electricity it creates needs to be conditioned in some manner…even more so than things like wind power.
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