Why do human electricity generation so focused on efficently boiling water and turning a turbine with it. do we have other ways of generating electricity every power plant i know (coal gas nuclear) does the turbine method ? And why is boiling water and turning a turbine with it so great ?
In: Physics
Making steam is the most efficient way to convert heat to electrical energy, all you need is a fuel and reliable source of water and you can make electricity 24/7 anywhere.
Steam generation and use through a turbine also create very little wear and tear on equipment so the equipment lasts for decades making it an ideal long term solution.
Lots of exceptions, as other have pointed out.
We get power by converting some other form of potential energy into electrical potential (voltage).
Water expands when it transitions to steam, creating a difference in pressure (potential energy) that can be used to convert mechanical action into electrical power.
Hydroelectric relies on potential energy from gravity rather than thermal expansion.
Solar cells generate current directly from EM radiation, so they act more like a receiver of transmitted energy than a generator or converter of chemical or gravitational energy to electrical power.
boiling water is just a super reliable way to create steam which spins turbines. i mean who doesn’t love steam right? it’s like magic water power. there are other methods like solar and wind but turbines just became the go-to for lots of reasons. just easy to scale i guess.
Spinning up a big rotor has the advantage of resisting demand surges on the grid giving you more stability steam is a great way of doing and it’s a mature technology
So, if you force electrons to move through metal (i.e., electricity), it produces a magnetic field. This is just how physics works. This is how, for example, electromagnets work to pick up large piecrs of metal.
Turns out the reverse is also true – if you induce a magnetic field near a piece of metal it will cause electrons to move in that metal. This is called magnetic induction and is how induction stoves and wireless phone chargers work.
In general (except for solar panels) we generate electricity using magnetic induction basically by taking a magnet and spinning it around a piece of wire. This causes the electrons in the wire to go back and forth, producing AC current. Sometimes we can do this directly with wind or water (hydroelectric), but for generating with gas/coal/nuclear the question is “what is the best way to continually spin a large magnet around something using the heat generated from burning coal/gas or from nuclear fission”?
Small gasoline-powered generators do this with a small internal combustion engine, but power plants dont use gasoline. Using the heat generated to boil water and then use that steam to turn a turbine is the best way that weve figured out how to do this that uses a plentiful resource and that is fairly efficient. The same basic design also works for all fuel sources.
You have a better idea of how to do this?
Even nuclear energy uses this same fundamental concept…. hot rock (reactor core) makes hot water, hot water makes steam, steam make turbine go brrrrr.
There’s obviously more to it than that… but those are the basics.
Entropy.
Currently, the grid has no energy storage mechanisms and energy is needed on demand.
The easiest way to consume energy on demand is to convert it from a stored form to an active electrical form. The easiest way to do that is going to be the one that has the largest entropy gradient. This is almost always converting some form of stored energy to heat.
And the most efficient way we’ve found to turn heat into electricity is steam turbines.
If we ever build good smart-grid and energy storage or demand management infrastructure, you’ll probably see fewer steam turbines in our energy generation: wind, hydro, solar.
I too was not impressed when I found out nuclear energy was merely steam generator.
To add to others, wind energy doesn’t boil water.
Turning a generator is the first way we made a significant amount of electricity, and it’s very compatible with the way our electric grids work. Until recently, it was impractical to make the 60Hz AC we use (or 50Hz in some regions) in other ways besides “turn turbine”.
In 2024 you absolutely CAN make power with a solar cell (DC) or a wind turbine (AC at unpredictable frequencies) then convert it with reasonable efficiency to the 60Hz you need but if you’re running a power grid, especially decades ago because big infrastructure lasts a long time, it’s a lot simpler if your generator just turns at a speed that produces AC power and matches what the grid needs.
The good ol’ “spinning magnet” can produce 60Hz AC power by spinning 60 times a second, or with 10 sets of magnets it could make 60Hz AC by spinning 6 times a second for example. And if you are spinning that turbine by pushing water or steam through it, you can control that and keep the speed where you need it to be.
For the longest time the only real way we knew to create electricity is… motion. Spin a thing with friction fast enough. Think like the bycicles or big hamster wheels that can generate electricity for its most basic form. And spinning a giant round thing through heat or water or wind running by over it is just the most scalable and efficient way we know to do that in mass.
In the last 20-30 years we started to find other ways. Both to use other motion (ie spinning magnets) as well as direct ways like modern solar panels.
But having a technology that works, and having a a technology be reliable, cheap and mass producible are two different things. A 100 years roughly passed between us inventing the combustion engine and cars starting to take over normal life. You can see the same starting to happen with renewable energy generation in the last few years. I remember around the early 2000s when everybody laughed at the idea of silly renewable green fancy ideas ever being relevant. Today it’s a massive portion of energy production in most developed countries going up. But these things take time.
The three biggest factors are (roughly):
1) technological readiness – cold fusion is already possible but right now running it costs more than the amount of power it creates is worth and its not yet mass producible. The tech simply isn’t there YET!
2) Public acceptance – transferring from one energy source to another will always be expensive to set up, initially expensive till we can get to a scale where factories compete to mass produce the parts cheaper, and will need people to make change behaviors. To get over this hill you need massive investments and those only happen if people really want a thing
3) Infrastructure – let’s take solar. Essentially 1) & 2) are ready. Solar panels these days are cheap, can almost endlessly be produced (as long as we don’t run out of resources) and people love it. So why don’t we slap solar panels on every roof in any nation with halfway decent sunlight and take all those turbine plants offline? Mostly because our entire power infrastructure (how the right amount power gets from the producer to the people) is built around generating massive amounts of power in one place, and then distributing it.
If we suddenly have hundreds of thousands of mini power producers in all these houses with solar panels, we have not built the cables and power nodes etc to feed that back into a system. We have no practical way to collect and distribute it.
We have all the technologies we need to theoretically do that… but overhauling the cables and power stations and software and ways of planning for charging demand (when people get home in the BBC evening they need more power than at night or midday)… that’s a MASSIVE undertaking that well cost billions, be a lot of work and take a long time.
And since the old system still works people do not yet want solar power bad enough to invest that amount of money and time.
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In reality there are even more factors in psychology, planning and how we build civilizations but this gives you a rough idea. Hope that helped 🤗
So TLDR: We DO have other ways to create power that are actually more efficient/cleaner but taking technology concepts to mass society standards takes a long time and tons of will/investment.
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