I'm sure a large enough mirror and photocell could get power out of the aurora borealis.
An argument that the magnetic field in a location remains completely constant as the earth rotates seems bizarre, but so does the idea that it's large enough to economically extract power.
I know they're a bit of an inter-related system, but I thought if anything tides mess with rotation (eventually causing tidal lock), not so much the other way around.
How big are the solar tides? Never really considered that tbh. Looked it up, they're about half the size of the Lunar ones? Wild.
The moon raises a bulge in Earth's crust and ocean. Earth's rotation carries that bulge ahead of the Moon's position. The bulge pulls the Moon forward (raising it to a higher orbit), while the Moon pulls the bulge backward (slowing Earth's rotation.)
Once Earth's rotation slows enough, tidal lock is reached. Then the tidal bulge stays in a single place always pointed at the relatively non-moving overhead Moon, and there is no motion to extract energy from.
if you've ever spent time at the seashore, the wind comes in off the sea during the day (because of rising thermals on the land side) and blows back offshore at night (because the land cools and the sea is now warmer) that time in between the air is dead-still, and that's when the swarms of gnats can find you.
Yet local winds blow in almost every direction. So to access that energy you'd need a structure 5 miles tall.
(via https://news.ycombinator.com/item?id=43520716, but we merged that thread hither)
> Even if it works, the method will not generate energy from thin air. It would tap Earth’s kinetic energy and, in doing so, cause the planet’s spinning to slow over time — although only slightly. If the technique provided all of Earth’s electricity needs, which was around 11 trillion watts in 2022, this would slow the planet’s spin by 7 milliseconds over the next century, the authors calculate. This is similar to the change in speed caused by natural phenomena such as the Moon’s pull and changing dynamics inside the planet’s core.
Like most things, nature is already doing it and has been for millions of years.
Interestingly, it looks like the upper atmosphere generally rotates faster than the planet, so it could be that the opposite effect actually dominates. IE the uneven heating causes a atmospheric bulge that actually pushes the atmosphere around slightly faster than the planet rotates, thereby slightly contributing to planetary angular momentum.
<https://oceanservice.noaa.gov/education/tutorial_tides/tides...>
Really puts how small we are on a cosmic scale into perspective.
If we did it for a million years at current energy use scale it would shorten our day by about 1.1 seconds.
That way a day can be 24 hours exactly instead of 23 hours, 56 minutes, 4 seconds, etc...
Its effectively the same principle as a figure skater pulling in their arms when spinning, to spin faster.
Calculate the change in the length of the Earth's day if the UK were to switch to vehicles driving on the right-hand side of the road rather than the left..
Presumably without roundabouts it's all random directions and balanced?
Or am I barking up the wrong tree?
Those tutorials filled me with dread at the time, but with hindsight they were - how can I put this - a fairly formative experience.
Watching your tutor use paper and pencil - and estimation - to calculate something like that was actually quite inspiring. That was, once it stopped being terrifying.
The only way you’ll care about what happens eventually is if you’re concerned about some detectable result. Meanwhile individual rocket launches to Mars extract like 10^18+ times as much energy as this will over it’s lifespan and those still aren’t detectable.
with energy, you need to consider friction, losses, thermodynamics 3rd law, but with momentum it's pure.
https://www.goodreads.com/book/show/700919.Signal_to_Noise
https://www.goodreads.com/book/show/737628.A_Signal_Shattere...
The first one was where I first encountered the idea of the "One Electron Universe":
https://en.m.wikipedia.org/wiki/One-electron_universe
A major plot point of these books is an alien technology that enables teleportation by somehow tapping into the Earth's angular momentum.
> Accompanied (for a while) by "gene witch" Zero al Qaseem and data paleontologist Isabel Mirabeau, Jack establishes a corporation based around one of the technologies he was traded by Wheeler, but soon finds that there may be more to his dealings with the alien than he bargained for. Traitorous alliances, deceitful propaganda, and shady business practices are frequent elements of the novel.
> "gene witch"
It seems hard to imagine that this kind of shrink-down could go on forever, but on the other hand, the earth is just sort of hurtling us around with great energy while it rotates.
Still... it would have been hilarious of the EmDrive had worked.
"Well, they've progressed! Last time we checked in on the third planet in this star system its inhabitants were still using warp drives to heat food. They appear to have realized this."
That's a good question actually. Supposedly this is extracting energy from the rotational kinetic energy of the earth. I haven't looked at the paper but you'd need to worry about conservation of angular momentum here.
Given that the cited physicists didn't dismiss this out of hand I assume this is accounted for somewhere...
If you did this on a massive enough scale, to generate serious amounts of power, would that accidentally slow the Earth's rotation down over time?
Given a field generated by asymmetric rotation of the molten core at the center of the Earth, 'shorting it' (apply a load) would presumably affect the core's rotation. In terms of relative energy however, the poor coupling at the surface would suggest that this would be a very challenging way to divert any meaningful amount of power from the core itself. It would however have to deal with points in time where the core reverses its magnetic field. The papers on core reversals are fun to read.
I think more usefully, the presence of the voltage, might be an interesting way to localize one's location and orientation.
I remember brainstorming "off the wall" power generation ideas and one that has yet to be realized would be to inject dust ahead of a wind turbine with a collector in the back. Then using the Van DeGraf effect to generate power instead of lightning as it currently does.
The main problem is that locally measured Earth magnetic field varies on a daily basis and is strongly influenced by solar storms.
A better alternative is to use variations in Earth gravity to improve inertial navigation. That vastly more stable.
"We previously showed that even in an extreme scenario where our civilization somehow would obtain all its electrical energy from the effect described here, Earth’s rotation would slow by <1 ms per decade [2]."
But I think if you do the math, it would be absolutely miniscule.
Actually, after some quick googling (so, maybe someone actually knows better) it seems like this is an issue where there’s an active discussion? Maybe somebody actually involved in the field knows more.
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2004JD00...
https://esd.copernicus.org/articles/3/79/2012/esd-3-79-2012....
But that came out in 2012. I bet you could find some other article citing it, as rebuttals.
It seems a bit implausible to think we could somehow pull enough energy from the wind to really matter, but then again carbon based climate change also seemed a bit implausible so, I guess, who knows?
No. Incidentally :)
I'm not an EE, but isn't this related to Tesla's last invention which bankrupted him - I believe he was working on electricity generation from thin air.
But this paper seems to imply that Earth, isolated from evening else in the solar system, could be made to slow down. This does seem like a violation of conservation of angular momentum...
I think the energy comes from weakening of the magnetic field and the energy stored within it, not from slowing down earth rotation. Earth as the result may rotate faster as the moment stored in the field will be transferred back to Earth as in the example with a sphere from the article.
This would not be good...
Don’t remember, exactly. It was a while ago.
Making total power for the 30cm shell = 0.44 picowatts.
If the concept of world-hopping intrigues you, Charles Stross's "Merchant Princes" series does it better.
I absolutely loved the premise of the first book. Every time I think about it I get the same kind of excitement I feel when I come up with the perfect idea for a D&D campaign.
But the second book gathers dust on my shelf, and no matter how many times I think "I should get back into these!" I just can't. The first book ended in a fizzle and the second completely failed to keep my attention.
I'll take a look at Merchant Princes and see if that's more to my liking!
Moment of inertia of the Earth: I=8.04e37
Angular velocity, with sidereal rotation period of 23.93 hours: ω0=2π/(23.93 × 3600)
Angular velocity, with sidereal rotation period of 23.93 hours plus one second: ω1=2π/(23.93 × 3600 + 1)
Rotational energy difference: .5 × I × ω0 ** 2 - .5 × I × ω1 ** 2 ≈ 4.96e+24 J
For comparison, according to https://ourworldindata.org/energy-production-consumption the total amount of energy consumed on Earth in 2023 was 180E3 TWh i.e. 6.48e+20 J
Slowing down the Earth by one second would be equivalent to 7661 times this amount.
The earth moment of inertia is about I=8e37 kg m2 [2]
The energy extracted by a slowdown of angular speed from wa to wb would be 1/2 I(wa2-wb2).
Approx wa=2pi/86400 and wb=2pi/86401. Energy extracted: 4.9e24J=4.9e12TJ.
We would have energy for about 12 billion years.
If I double check with Kagi's assistant with Claude 3.7 (I'm in my phone and I could easily have made an error) it starts with my exact reasoning and figures but messes up final numbers (so close!!!) to give a total of 40 billion years, which nevertheless is the correct order of magnitude.
[1] https://en.m.wikipedia.org/wiki/World_energy_supply_and_cons...
[2] https://scienceworld.wolfram.com/physics/MomentofInertiaEart...
Keep in mind that energy is not electricity. When a rocket is burning huge amounts of fuel to reach orbit, that's energy we're using, a lot of it.
I suspect that they can generate electricity with angular momentum with it, that can be only used to do work with the equivalent angular momentum.
Spoiler: they nuked a bunch of stuff.
It’s hard to beat solar though.there are very few technologies that stack up better financially than “just buy more panels” in most of the populated world. Batteries are really the key.
A magnetorquer is an attitude control system on a satellite that runs on electricity. Run the electricity through an electromagnet. The magnet couples to Earth's magnetic field and turns the satellite, like a compass needle.
[1] https://en.wikipedia.org/wiki/Earth%27s_magnetic_field [2] https://en.wikipedia.org/wiki/Dynamo_theory
The Earth rotates, liquid iron (inside Earth) flows => a current flows in the iron => there is a magnetic field.
Side story: What's to argue over?
There's no shortage of scientists with breakthroughs who are pretty much abused by their profession and colleagues, sometimes for decades, simply for exploring possibilities and capabilities that are more than safe and conservative and incremental.
Either it's true, or it's not, and it can be explored, or not.
Division breeds who is right and wrong, not what is right or wrong.
Maybe it can be proven, maybe not. Maybe it's true and we don't understand it yet. The naysayers might just not be wanting someone else to succeed.
A related topic, the emDrive, which had plenty of controversy, is something readers of this thread want to talk about; the specifics are a better fit for this crowd than the meta questions, esp. when vaguely introduced.
Even happier to get input and maybe learn.
Magnets too - let's just go magnets everywhere.
Reality is solar isn't viable everywhere. And it's not optimal to put it in places where you use the sun to grow food.
We should follow a holistic approach.
* Wind where it's windy.
* Solar where it's sunny - ideally on buildings/away from farms.
* Hydro where possible.
* Nuclear where it makes sense, i.e. stable geography, low occurence of natural disasters, lots of land.
* Some natty gas plants for overflow - not saying commission new ones or prioritize natty, but it's sensible to utilize existing peaked plants.
I'm not a big fan of large scale battery storage solutions, but they can work sometimes. I think they're more sensible for residential/commercial use and, when paired with solar, can really help add robustness to the grid. But, for mega energy storage, I think hydro based solutions are more sensible.
Also there is a ton of research on planning energy systems and what technology mixes make sense. This stuff has to be economical. Energy costs are measured in percentage of GDP. Simply liking nuclear doesn't make it viable. Especially in a world with PV meaning you can't sell energy during the day.
There really is only one macro fact that will shape the energy system of the future: The price of PV modules is now effectively zero in rich countries. Everything else has to be judged by how well it complements/makes use of free energy during daylight hours. The geopolitical implications of this haven't even begun to be explored.
You don't want a state primarily on solar if you get a super cell darkening the sky for a week.
You want a mix of renewables, but you don't strictly want to rely on the food graces of mother nature at all times.
Boiling things down to just price is a very simplistic view.
Obviously you want a tech mix, and obviously anyone working in the field is taking the dunkelflaute or other extreme events very seriously. That's where storage comes in, and that's where the biggest unknowns and needs for future development are (e.g. is seasonal H2 storage really feasible). But to pretend like nuclear can magically become cheaper through technical breakthroughs, while storage is an unsolvable problem is disingenuous.
It's also disingenuous to suggest that random fluctuations in weather are somehow a unique problem. Sudden unscheduled maintenance can take down nuclear plants as well. As can the weather: Nuclear power plants require cooling and can be shut down due to weather and climatic conditions, too [1].
[1] https://www.nature.com/articles/s41560-021-00849-y
> I analyse climate-linked outages in nuclear power plants over the past three decades. My assessment shows that the average frequency of climate-induced disruptions has dramatically increased from 0.2 outage per reactor-year in the 1990s to 1.5 in the past decade. Based on the projections for adopted climate scenarios, the average annual energy loss of the global nuclear fleet is estimated to range between 0.8% and 1.4% in the mid-term (2046–2065) and 1.4% and 2.4% in the long term (2081–2100).
I didn't say storage was not solvable and I even gave a better storage solution than your silly "batteries" example.
> Based on the projections for adopted climate scenarios, the average annual energy loss of the global nuclear fleet is estimated to range between 0.8% and 1.4% in the mid-term (2046–2065) and 1.4% and 2.4% in the long term (2081–2100).
From your own linked article - do you think this energy loss is even close to comparable to solar for similar conditions? You've linked an article but don't seem to understand the point they're looking to make.
Anywho, I don't think you're looking to argue in good faith and seem to have an anti-nuclear agenda, despite talking about an "energy mix". Save your policies for whatever echo chamber they were derived from, thanks.
If seasonal storage is solvable, solar + wind is not unreliable.
And no, I don't have an anti nuclear agenda. But I know the energy system models and the results, and just how difficult integrating nuclear into the mix is.
https://nworbmot.org/blog/burden-of-proof.html
Finally, I know exactly what the paper says but maybe you don't: the problem with Dunkelflaute events is correlation. If it's cloudy somewhere and the sun is shining elsewhere, then no problem. These problematic conditions for nuclear are the same: large scale spatial correlated.
Great. We'll just pipe over the energy from Arizona to Michigan, should be fine.
Large scale weather events drop nuclear by 1% long term. What percentage do they do for solar?
I'm not even a solar hater - I love solar... On residential and commercial rooftops. Or in sunny and void of life areas.
I love a mix. And nuclear integrates just fine into the mix. Look at a province like Ontario where 60% of the energy is derived from hydro and nuclear. An incredible and robust baseline power with low downtime and, correspondingly, cheap power for all of the residents of that province.
Even more energy from solar and wind too, with some natty gas as top off. Seems to work just fine for them - and with long winters and plenty of cloudy days, solar as a big component of their energy mix seems pretty silly to push for. You can see the mix live below.
https://live.gridwatch.ca/home-page.html
It was 53% nuclear and 28% hydro at the time of me posting this. 16% natty, 4% wind, and 0.1% solar. The solar was good for 21 MW and the nuclear was good for 9600 MW for perspective. Their nuclear has been safe as hell and has run flawlessly for I think 30+ years.
You can absolutely sell non-PV power during the day. Big power consumers sign contracts for predictable and reliable supply.
LCOE takes some of the system costs into account, but it's of course true.
And your second sentence is not how energy markets actually work. Of course I make a contract for reliable supply, but I don't contract with an individual power plant. I contract with an energy company and that buys from the cheapest supplier mix (aka merit order).
The long term contracts for base load run for years, but those, too will eventually have to adpat to the reality of abundant cheap daylight energy.
My main point with PV isn't about the system we have right now. It's that we are in the first days of a new system structured around the new technological reality that only recently emerged. Until very recently nobody, even the optimists, expected PV to get that cheap that fast. It will take decades for the repercussions of this phase transition to shake out. The issue is, due to climate change we don't have decades.
Also, remember that nuclear, unlike solar, has a lot of room for improvement still, both in how it's done, and how it's regulated. Solar has already been tremendously optimized, while nuclear has not.
The cost argument seems to be advances by the same people who impose or support the additional operational requirements, and who also just have a philosophical aversion to nuclear power.
There are hundreds of nuclear power plants already in operation, many decades old. There have been only a very small number of minor accidents (3 come to mind: Chernobyl, Three mile island and Fukushima), in which only a few dozen people were killed. Nuclear, even using old technology, has proven to be far safer and better for the environment than any scalable alternative, including solar. New designs are even safer.
Nobody died from installing asbestos insulation yet here we are.
Indeed. Once there was a wonderfully efficient, economical nuclear reactor design, better thermal efficiency than PWRs, could be refueled during operation, considerably cheaper to build… However, nobody is THAT keen to build more Chernobyls.
(The RBMK design really was quite impressive, provided you weren’t too concerned about, well, safety.)
The economics of nuclear energy are difficult, today. So much of the cost is upfront that getting the investment is problematic; unless you have a guaranteed price per kWh, it really is a huge gamble.
Nuclear has had tremendously more cumulative R+D spend than solar and wind. The notion that it's less optimized is absurd. And this is where your bias shows: we have empirically proven persistent scaling laws for solar and batteries. We also have seen nuclear become ever more expensive over time. Yet you claim that these trends will come to an end, and in the case of Nuclear will suddenly completely reverse themselves without any evidence.
To also bemoan the burdensome operational requirements while championing it's safety record is internally inconsistent.
And in the end no one has so far actually built a place where you could store the nuclear waste long term, and the costs of long term storage are not even fully factored into the costs of today's nuclear power plants.
I'm all for doing more, and improving our lot incrementally over time. Let's focus on doing more wherever we can.
Why is nuclear getting more expensive over time? Are we forgetting how to produce it or something? Actually we've been finding more efficient and safer ways to produce nuclear for decades, but we impose - as I said - artificial burdens that make it more expensive, or simply don't allow it at all. At least in the US.
The operational requirements DON'T make it more safe though, they just add cost. Storing nuclear waste is also safe, easy and cheap - if we allow it to be so.
Do you have some sources for operational requirements not making things safer? And as far as I know there are plenty of fusion concepts in the lab, but very few that have actually been explored at the full reactor scale. If you have any pointers on recent developments in that direction I would also be curious to take a look.
But then I also have to ask why nuclear? Why not methanation (or hydrogen if storage becomes feasible) and gas power plants or some more sophisticated version of that? That has much better complementarity to solar. And it typically is preferred to nuclear by energy system models wherever seasonality is strong.
Also I haven't really seen any proposals discussing long term waste storage. Again do you have any sources that discuss this?
I'm a lftr fanboy, but nuclear had its time to optimize.
I can't believe you're calling Chernobyl "minor". Go take a vacation there if you disagree.
Anyway, nuclear is not cost competitive in the real world, imo it never will be with solid fuel, nor will it be safe. Certainly not with standards like yours.
In what way is it not? It has a budget and a mission. Economics are a huge part of their existence. Far more is spent on health care every year over the Navy.
At the same time, they invest in those mobile nuclear reactors only for specific needs: attack submarines, ballistic missile submarines, and aircraft supercarriers. They calculate that the benefit of effectively unlimited fuel supply is worth the cost for those ships. The submarines can stay submerged for months at a time and have extensive range, and the carriers can move through the ocean, displacing 100,000 tons of water, to anywhere on the globe without worrying about the logisitcs of the enormous amount of fossil fuel it would require.
And solar less so than nuclear. Nuclear receives only ~1-3% of energy subsidies in the US [1].
[1] - https://en.wikipedia.org/wiki/Energy_subsidies_in_the_United...
I used to have a neighbor who worked for the DOE, all of the viable solutions are blocked by people who don’t want it in their backyard. Can’t really move forward until that is solved..
The correct solution: put it into dry casks and do nothing right now. Store it simple underground storage facilities or on the grounds of active nuclear power plants.
The casks are fine for the next 300 years, and during that time we can either:
1. Perfect the nuclear fusion, it will provide plenty of neutrons to transmute the waste.
2. Perfect fast fission reactors. See above.
3. Use some of the excess of too-cheap-to-meter green energy for accelerator-driven subcritical fission reactors.
4. Yep, use rockets to slowly launch the waste into space. We can already design a storage capsule that can survive re-entry.
In any case, we have literally hundreds of years to come up with a solution and there are many viable paths.
Do you have a source in mind for this claim? Even if a capsule could survive reentry, surely it wouldn't survive impact.
> Even if a capsule could survive reentry, surely it wouldn't survive impact.
It'll be moving at a terminal velocity, and can be engineered to not fragment on impact.
For example, I remember reading about a proposal to alloy the nuclear waste elements with a carrier metal like iron or nickel, and then cover them in an ablative graphite shell.
Of course it is more or less equivalent when it comes to handling.
Could the waste be 'sent' into space? Bonus points for sending a certain human with it. Serious question, though.
Would you want a RUD of nuclear waste in the atmosphere? That's the key thing with sending stuff to space, we are nowhere near close enough in terms of reliability and cost to what would be needed to send the stuff away.
IIR, the current rock-bottom (Falcon 9) launch prices are something like $1,000/lbs. to low earth orbit, $2,500/lbs. to geosync, and $6,500/lbs. to Venus.
A quick Google says the US has about 88,000 tons of radioactive waste. So - 88,000 tons = 176,000,000 lbs. = $176,000,000,000 just to put it in low earth orbit. And something like 4,600 Falcon 9 launches. (Some fraction of which would doubtless go badly wrong, spreading radioactive stuff all over the landscape.)
In short - it's a cool-sounding idea. But neither the numbers nor the politics are remotely near viable.
I don’t think this invalidates your point but I do think it is incredibly important to recognize that environmental harm done slowly over time is no less impactful than that done by a disaster.