131–140 of 252 posts
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> sometimes fossil fuels are a good fit There is simply NO safe level of fossil fuel use.
I don't know what you mean with "no safe level of fossil fuel use". It doesn't mean anything without contextualizing that statement.
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Agreed, whenever I hear someone say "we need more/less nuclear and less/more solar/wind", I hear "let's burn more fossil fuels while we uselessly split hairs".
Unless the scenario is totally different where you live, pro-nuclears are mainly "we need more nuclear, less rerewables, don't care about fossils, just guaranteed production", while pro-renewables are mainly "we need more renewables, less or no fossils and as few nuclear as possible". If someone is getting wiped from the mix because of renewables, it is coal and fuel, not nuclear.
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How do these things, whose sole purpose is to turn heat into electricity, end up with so much extra heat that it takes more energy than they produce to disperse it? Can't the excess heat in a closed loop system be captured and used to power the cooling? Sorry, maybe this is a stupid question.
Thermodynamics, specifically the Carnot Cycle. Heat engines do turn heat into mechanical energy (motion). What they don't do is do this with infinite efficiency. In practice , Carnot engines (heat engines) tend to operate at efficiencies between about 20 to 50%, with an average close to 30% percent. This means that most thermal electrical generation produces roughly three times as much heat as it does electricity. Th…
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You're probably going to struggle to come up with a motive for that behaviour. It is much more likely that they simply aren't very thoughtful. Complex webs of deception in a public argument are certainly possible, but it generally relies on some group having a clear financial incentive to misdirect. That doesn't exist in the nuclear debate.
> a clear financial incentive to misdirect. That doesn't exist in the nuclear debate. It's very obviously not in the interests of "big fossile" to go either solar or nuclear.
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Plot twist, the experts are lobbyists and they convince our politicians to start fracking and massively increase the use of "clean coal"
I would be willing to bet on a board of PHDS of varying sciences they would determine that coal is dumb and a waste of money
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Thermodynamics, specifically the Carnot Cycle. Heat engines do turn heat into mechanical energy (motion). What they don't do is do this with infinite efficiency. In practice , Carnot engines (heat engines) tend to operate at efficiencies between about 20 to 50%, with an average close to 30% percent. This means that most thermal electrical generation produces roughly three times as much heat as it does electricity. Th…
Wouldn’t a Carnot engine with 33% efficiency produce 2 J of heat per 1 J of mechanical work? With 40% efficiency 1.5 J of heat? Efficiency of the generator should be better than 90 % so I think the 3x estimate is a bit off.
If you look at real-world numbers, you're generally going to see 3x the thermal output as electrical output from any thermal energy plant. Two-thirds of that thermal output is wasted, and you'd see your 2x figure there. But the useful electrical output eventually ends up as heat as well, whether in direct thermal applications, from mechanical applications, lighting, refrigeration, audio equipment, or electronics.
The (admittedly theoretical) numbers in this example show that:
https://energyeducation.ca/encyclopedia/Megawatts_thermal>
Incidentally: this all-but-inevitably leads to an online hand-wringing about the inefficiency of energy systems when an energy flow chart (Sankey diagram) is released, showing a 2:1 "rejected energy" ratio. It turns out that that's not a measured quantity but a modeled quantity, if you read the fine print. The 2/3 loss is just physics, thermdynamics and Carnot as noted previously.
See for example the LLNL (Lawrence Livermore National Labs) energy flow chart diagrams, here for 2023: https://flowcharts.llnl.gov/sites/flowcharts/files/2024-12/e...>
Some of those qualifications are more legible in the fine print of the PDF: https://flowcharts.llnl.gov/sites/flowcharts/files/2024-10/e...> (PDF).
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I don't know what you mean with "no safe level of fossil fuel use". It doesn't mean anything without contextualizing that statement.
There is already too much carbon in the atmosphere.
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There's a nuclear reaction in the sky beaming free energy to us, let's just use that
Hungary is already using that (today we were 90% carbon-free thanks to solar), the problem is what to do when it gets dark.
[0] https://en.wikipedia.org/wiki/Wireless_power_transfer#Microw...
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There's plenty of work happening with adapting non evaporative cooling loops for data centers. Maybe that can be applied here too, even if to mitigate some of the cooling needed?
Data centers can afford to spend way more per kWh of heat discharged. Nuclear needs to dump 3+kWh of heat per kWh of electricity generated.
Nuclear discharges more like 2kWh of heat per kWh of electricity produced.
Perhaps slightly more, but its in that ballpark. Seems like a small difference but you are overstating the waste by near 50%.
Source: Degree in Nuclear Engineering, previous life was a Reactor Operator. Also, just look up thermal efficiency of currently operating reactors.