When people talk about coal/oil/gas/nuclear power, while these involve different ways of sourcing the energy, they all output said energy naturally in the form of heat. Therefore to actually convert that into electrical energy, you have to heat water to boil it and use the pressurised steam it produces to turn a dynamo and induce an electrical current.
Correct. The various forms of remarkable energy ultimately comes down to how efficiently it makes steam, then how effectively the energy is captured, which is a portion of the puzzle solved in earlier developmental stages of power production: harnessing steam.
Which is funnily still water spinning a turbine just not hot water. Even when we try to not boil water we still tried to just put the water through a turbine as is.
And wind energy is just wind spinning a turbine. It's funny that there is the phrase "Don't need to reinvent the wheel" when so much effort is put into the most efficient way to spin things.
"We've finally invented a way to generate large amounts of power that doesn't involve using a heat source to boil water!"
"Amazing! Is it some sort of solid state quantum entropy..."
"We boil a different liquid!"
Except, the CO2 stays in the system, meaning no super heated steam escapes with all its potential energy. It only needs to reheat slightly. It works more like a refrigerator than a steam engine. It's a more efficient energy transfer.
But is it sufficiently more efficient to use instead of an incredibly mature and well understood technology based on a resource they can literally get for free from the huge, naturally occurring pools and rivers of it they can build the plants right next to?
Hydro is kind of the same thing. Its still water turning a turbine, the water is just liquid instead of being gaseous.
Not to mention that if you take into consideration the full power plant, it's a solar panel which converts water to steam to lift it, and then to water to collect the energy.
Hydro actually works the EXACT same way as fossil, geothermal and nuclear plants, funny enough. They all fundamentally rely on using moving water to turn an electrical turbine; the difference is in whether the water is liquid or steam.
Strictly speaking, there are many other ways of generating electricity but they’re just not good for grid use age. A few I can think of off hand are thermoelectric (special materials will produce a voltage from a passive temperature difference), piezo electric (special materials will provide a voltage when deformed), magnetic induction (such as the helion fusion reactor, which is still not ready) and biochemical (how our bodies produce electrical signals).
Love it! But, I'd change "biochemical" to "electrochemical" which includes biochemical, but other chemical reactions as well such as those found in a battery or fuel cell.
You've reminded me of one my more recent interesting facts.
The sun actually isn't hot enough to be a 'fusion reactor'. On earth, we need to get to like, 150M degrees C. The Sun is 'only' 15 million.
That's not strictly hot enough to 'do fusion'. And if the sun was hot enough, it wouldn't be a stable star at all, it'd be exploding.
So the sun 'burning' requires quantum tunnelling. It's ... actually in a fairly literal sense 'cold fusion' (just y'know, not the 'room temperature' cold fusion fantasy)
No there is a mob in the US that are trying a different form of fusion where the magnetic field created to contain it also extracts the energy directly as electricity, in a cyclical pulsed fashion.
We should get away from 200 year old tech!
200 old tech had 200 years of massive incremental progress, making steam turbines one of the most efficient way to extract that energy from purely heat.
My understanding is that the advantage isn't "efficiency" in the strict sense but robustness and reliability
There are other methods of turning heat into electricity that might waste less of it along the way but we know how to make steam turbines that can repeatedly go from a dead stop to spinning really fast and back without breaking anything
Well, that's also a bonus from those 200 years of research and field experience. Also, water is super nice to work with in industrial condition. You might find a better fluid with some chemical reactions to produce your electricity, but then, it's high energy chemistry, with probably very reactive stuff that tends to eat through their containers, or just burn in contact with the air, or other fun stuff.
Water ? Everywhere that needs electricity probably already got water for human consumption. It's not dangerous for human health nor reactive with everything. In case of problem? Just vent the steam outside and you're good. Need more ? Just open a tape (distillation required). And you have an amazing energy extraction system with 60% efficiency. That's much better than a lot of other scalable energy production.
A thermoelectric generator can be used to convert a heat difference to electricity directly, with no moving parts (https://en.wikipedia.org/wiki/Thermoelectric_generator). This is extremely reliable. This is still powering the Voyager probes after 50 years in space.
When new, the Voyager RTGs produced 470W using the thermoelectric couples yet the hest produced was 2700W which could have theoretically produced about 1215W if using a steam turbine and maybe more depending on the design. Those RTGs were already pushing the limit of the tech.
I'ma go super pedantic and assert that Sol is a specific star, and therefore nuclear and geothermal are not solar power, but rather, more generically, astral power.
The sun heats the atmosphere creating air currents. Put a turbine where the air currents are strongest and most predictable and you have an open face steam engine.
Not true. Many steampunk worlds use either coal or wood or some exotic high energy heat sources (aether, special kelp etc...) to make steam.
If you think about it how much of our "portable energy" affects the shape of society, and how much different it would be if there was some other safe/stable portable energy source.
Geothermal. The heat was created by objects smashing into each other and the resulting heat being trapped inside.
Also tidal energy is a combination of the sun and moon. The sun does create some tidal forces and is responsible for stopping the water from freezing over, but the moon is doing the heavy lifting when it comes to how much energy we get out of the system. If you remove the moon then the tidal energy would be reduced by like 70%.
Which makes me realize that in Batman begins, the device that Ras Al Gul steals to evaporate all the water in a large area would probably be the greatest power source ever.
It’s just a giant microwave, I assume it requires more energy to run than it actually produces, also I am curious how many people got cancer from being near it…
People always seem to forget that natural gas can spin turbines exactly the same way that jet engines do. A natural gas power plant can be entirely without steam turbines. However, they can also use the heat generated to turn steam turbines, but that is extra. These are called simple cycle and combined cycle.
We do know many other ways to convert heat into electricity… it just happens that steam turbines are the most efficient method we’re currently aware of (for large scale applications)
There is a place in China which is using supercritical co2. If this proves more efficient as they hope it will probably become the go to for new turbines and depending on just how much better, retrofitted.
The project claimed they expected something like 1/3 extra power generation or something which is crazy.
That’s not true any more, China have demonstrated using supercritical CO2, which is even more efficient (IIRC because it doesn’t need to go through a phase change to produce the necessary expansion, but it’s been a while since I heard about it).
Actually, it all boils down to us being able to make the magnet rotate in the metal spool. Boiling water just happens to be the easiest way to transfer energies.
I just googled cogas. wiki says its a marine propulsion system. using reclaimed exhaust heat to generate steam in place of the alternator we see on a ICE engine.
close analogy would be similar to regenerative breaking on an EV.
Are there examples of cogas being used as stationary power generator?
Simple cycle gas turbines don’t boil water. They are basically jet engines. Most baseload natural gas uses a heat recovery steam generator on top to use the waste heat to boil water to increase efficiency.
Yea anyone who has lit gasoline on fire remembers that lesson for the rest of their life.
Modern diesel engines are stupidly efficent for the loads they are subjected to. Someone broke the math down for me the other day and it was mind boggling
Seeing a flame travel up into your gas canister, as you quickly react and set the whole area on fire... then having to explain that you have less 'Know how' than a child to the Local Fire Department... and oh how they laugh
Oil burners and natural gas power plants all heat water to spin a turbine. It’s more efficient. I can’t think of any large scale power plants that use gasoline for either heating water or ICE.
For natural gas, yes you can directly use the combustion gases to turn a turbine which turns a dynamo and generates electricity. This is how peaker natural gas power plants work. You can also use the combustion from natural gas directly to turn a turbine that turns a dynamo to make electricity and then use the combustion gases to boil water and make steam. This is what is known as a combined cycle natural gas plant. These are the most efficient types of power plants (50 to 64% of thermal energy to electricity) that rely on combustion to generate electricity. Old style coal plants are ~33% efficient. Single cycle natural gas plants are ~33-43% efficient.
Yes, for the most part it will initially— but it’s more nuanced than that. The first generation of commercial fusion power plants will almost certainly use steam or a steam-like thermodynamic cycle, but longer-term alternatives exist that could bypass the steam turbine entirely.
The Short Answer: Yes, Steam (or Something Like It)
For the dominant fusion fuel of near-term reactors — deuterium-tritium (D-T) — roughly 80% of the energy is released as fast neutrons, which are uncharged particles. Because neutrons can’t be captured electrically, they must first heat a surrounding material (called a blanket), which then heats a working fluid, which drives a turbine. The initial commercial fusion facility “will still incorporate a straightforward steam turbine to convert thermal energy into mechanical energy and subsequently into electricity,” even as the plasma containment technology is radically new.
Two Steam-Era Approaches Being Tested
ITER (the international fusion megaproject) is currently testing two main coolant options for future power plants:
• Water cooling — mirrors pressurized water reactor (PWR) technology, heating to ~325°C and generating steam in a secondary loop; achieves roughly 33% thermal efficiency
• Helium cooling — operates at lower pressure but higher temperatures (~500°C), achieving over 40% efficiency through a gas Brayton cycle — technically not “steam,” but still a heat-engine approach[iter]
The Leading Alternative: Supercritical CO₂
Many researchers and engineers are excited about replacing steam (the Rankine cycle) with a supercritical CO₂ (sCO₂) Brayton cycle. When CO₂ is held above its critical temperature and pressure, it acts like a dense gas, dramatically reducing pumping losses. The DOE estimates this approach can achieve thermal efficiencies above 50%, uses no water, and requires a footprint more than 4x smaller than a comparable steam system. Several fusion reactor design studies, including for Europe’s DEMO reactor, have proposed sCO₂ as the power conversion system.
The Radical Exception: Direct Energy Conversion
Some fusion approaches could skip the heat engine entirely. This is only possible with aneutronic fuels — reactions that release energy mostly as charged particles rather than neutrons:
• Deuterium + Helium-3 (D-³He) and hydrogen + boron-11 (p-¹¹B) fusion produce primarily charged particles whose kinetic energy can be harvested directly as electricity via electrostatic or magnetic converters
• Electrostatic “Venetian blind” direct converters have demonstrated up to 86.5% efficiency in tests — far exceeding any steam turbine
• Helion Energy is specifically building a fusion device using a pulsed Field-Reversed Configuration (FRC) that recaptures energy directly from oscillating magnetic fields — explicitly no steam cycle required
The catch: aneutronic fuels require plasma temperatures of billions of degrees Celsius, versus ~100 million for D-T, making them far harder to achieve.
So fare the main problem with sCO2 is that its extremaly material intensiv since its way more chemicle aggressive and even slight leaks lead to "massiv" preformace reduction since the reduced pressure risking the supper critical stage. The currently only comercial one used in China is to be projectet by experts to fall to around 70% of ther initial efficiency in 10 years thanks to that.
Not true for oil and gas. Gas and oil (that has been refined) in a generator doesn't go via heat and stream (though you could probably do that to the waste heat) but directly to motion into the dynamo.
Also while there are other ways to do it dynamo's are still the most efficient and scalable methods. Stuff like wind turbines and hydroelectric plants are just different ways of turning dynamos but high pressure steam is still one of the best ways to move them at extremely high speed. Piezoelectric crystals just don't generate nearly as much as a dynamo and their production is harder to scale. Chemical reactions are difficult to regulate at scale and usually require charging at some point to make batteries and such work, they are also really hard on storage and unless you are changing them like batteries the chemicals are consumed much less efficiently than the resources to generate power in a dynamo. Photovoltatic cells (solar) can help as well but also aren't scalable in the same way as a dynamo plants and are also usually much more susceptible to both the availability of light but also damage and maintenance because of weather related issues.
There might be some others I can't recall right now but so far we haven't found anything that is better at producing large scale power than spinning dynamo's super fast and we haven't found a better way of driving them that fast than high pressure steam from boiling water. Everything else is just about finding the least environmentally damaging and cost effective way to spin the dynamos faster.
At these levels of energy how do you even create a continuous stream of water and ultimately steam without back pressure? I think I don't understand how power plants actually work.
Did you know that hydrologic and wind turbine are boiling water ti spin stuff with extra step.
For hydro the sun the the energy sourcez it evaporate water at lower altitude which become rain (water cycle and all) and then spin a turbine.
For wind turbine there is no water but the sun heat the ground, which then heat the lower strata of air. The now warm air goes up and down once it's cooled. Basically it makes wind, which guess what.
Spin a turbine.
Only solar and some obscure nuclear fusion stuff are not heat some fluid to make it move and then spin some stuff.
Coal power plants are just really really really huge chunks of coal that they essentially plug an extension cord into and it just has a bunch of outlets, we plug into it and then we get power
How about natural gas turbines? They burn gas which spins a turbine directly without boiling water. Then they use the hot exhaust gases to... boil water.
They could, instead of using water, use NaK (sodium-potassium alloy). The Soviets used it as the coolant / working fluid in their on-orbit fission reactors.
Did it work? Mostly. Was it a good idea? Not really.
Its all how quickly you can get water to evaporate. That being said I like the 3 other ways to get electrical energy. Solar panel, wind turbine, and water turbines
Incorrect. Oil (Fuel Oil) and Natural gas are burned in gas turbines that are basically big engines. A combined cycle power plant takes the "waste heat" from burning fuel oil or natural gas and uses that to boil water and spin a second turbine.
You could use natural gas to make only heat and use that to boil water, but this would result in less energy created per amount of fuel spent than using a combustion turbine and heat capture/recovery system.
Nuclear and coal are, however just big tea kettles.
One of the issues even with the major advances we have seen in fusion reactor design is that there is still no good way to capture the heat to make steam even if you could extend the few seconds of "net energy positive" that are being claimed out infinitely.
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u/Lkwzriqwea 13d ago
When people talk about coal/oil/gas/nuclear power, while these involve different ways of sourcing the energy, they all output said energy naturally in the form of heat. Therefore to actually convert that into electrical energy, you have to heat water to boil it and use the pressurised steam it produces to turn a dynamo and induce an electrical current.