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Can Earth's rotation generate power? Physicists divided over controversial claim

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Re: Can Earth's rotation generate power? Physicists divided over controversial claim

#201

Post by thayne »

frozencooler wrote: post #42
ziofill wrote: post #25

Wouldn't this eventually slow down Earth's rotation? The rotational kinetic energy of our planet is 1/5 M * R^2 * w^2 with (approximately) M = 6e34 kg, R = 6.3e6m, w = 7.4e-5 rad/s, which gives approximately 5e36 joules. Yearly we need roughly 3e16 Wh. Yeah ok there's plenty. Woah! (also, I may be off by some orders of magnitude)

Doesn’t driving west to east on a highway slow down the Earth’s rotation, via the power transferred into the ground?

Then when you stop the angular momentum of your car is transferred back to the earth.

Re: Can Earth's rotation generate power? Physicists divided over controversial claim

#202

Post by bmacho »

pmontra wrote: post #54
EncomLab wrote: post #45

It's incredible the lengths humanity is willing to go to avoid adopting nuclear energy - despite the US navy driving mobile reactors millions of miles over the last 70 years.

Many countries would have to buy nuclear fuel from other countries much like they do for gas and oil. On the other side very few countries can build their own solar panels so it seems the same sort of problem. However if you accept to depend from potential hostile countries at least solar panels don't do much harm when they fail and it takes very little effort to install the equivalent amount of power of a nuclear po…

You can do solar energy with mirrors (the ancient Greeks were able to produce that) and steam turbine/stirling generator.

Re: Can Earth's rotation generate power? Physicists divided over controversial claim

#203

Post by Certhas »

Nifty3929 wrote: post #62
deepfriedchokes wrote: post #51

Earlier quoted context omitted.

The Navy isn’t constrained by economics. Nuclear doesn’t make sense economically compared to things like solar and batteries.

I haven't seen any data that backs that up based on general principals. Most of the cost is in artificially-imposed operational requirements - however well founded. 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 peo…

All I see is people with an aversion to solar and wind, that champion nuclear for purely ideological reasons. The aversion seems to be mostly driven by the fact that solar and wind were first championed by eco hippies, and some people seem to find it hard to bear that the eco hippies were right in this case.

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.

Re: Can Earth's rotation generate power? Physicists divided over controversial claim

#204

Post by Certhas »

SecretDreams wrote: post #175
Certhas wrote: post #132

Earlier quoted context omitted.

What do you base all these claims on? Plenty of papers show Solar + wind + storage is viable practically everywhere. 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. The…

Energy independence and a mix of technologies isn't just about cost. It's about redundancy and how you're positioning yourself to handle various unexpected events. 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…

You seem to think this contradicts my statement somehow?

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).

Re: Can Earth's rotation generate power? Physicists divided over controversial claim

#205

Post by Certhas »

mike_hearn wrote: post #144
Certhas wrote: post #132

Earlier quoted context omitted.

What do you base all these claims on? Plenty of papers show Solar + wind + storage is viable practically everywhere. 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. The…

The (subsidized, market dumped) price of cells may be low at the moment, but the price of storage, land and artificial inertia isn't. You can absolutely sell non-PV power during the day. Big power consumers sign contracts for predictable and reliable supply.

PV is not heavily subsidized compared to other energy carriers, and the learning rate has been extremely consistent for a long time.

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.

Re: Can Earth's rotation generate power? Physicists divided over controversial claim

#206

Post by aaron695 »

peterashford wrote: post #120
sroussey wrote: post #86

The Earths rotation already generates power for us: wind. It’s why the jet stream only goes one direction.

Wind power is mostly due to solar energy. Earth's rotation contributes a very small amount and even that smaller effect is more located in the upper atmosphere where we don't collect wind power versus solar caused pressure gradients

[dead]

Re: Can Earth's rotation generate power? Physicists divided over controversial claim

#207

Post by K0balt »

I mean… yes, the earth’s rotation can easily generate power. All you need is a gyroscope spinning in a vacuum on frictionless supports to make that work. Of course it’s only 1 revolution per day, but still, if it’s big enough…

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.

Re: Can Earth's rotation generate power? Physicists divided over controversial claim

#208

Post by api »

OccamsMirror wrote: post #195
api wrote: post #80

Earlier quoted context omitted.

> 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. 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.

Wouldn't it extend our day?

Yes. Had it backwards.

Re: Can Earth's rotation generate power? Physicists divided over controversial claim

#209

Post by SecretDreams »

Certhas wrote: post #204
SecretDreams wrote: post #175

Earlier quoted context omitted.

Energy independence and a mix of technologies isn't just about cost. It's about redundancy and how you're positioning yourself to handle various unexpected events. 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…

You seem to think this contradicts my statement somehow? 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 techn…

> But to pretend like nuclear can magically become cheaper through technical breakthroughs, while storage is an unsolvable problem is disingenuous.

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.

Re: Can Earth's rotation generate power? Physicists divided over controversial claim

#210

Post by ziofill »

aeternum wrote: post #200
mr_mitm wrote: post #148

Earlier quoted context omitted.

No, that's not possible due to conservation of angular momentum. Only tidal effects can transfer some of it to the sun.

Why would angular momentum be conserved? Rotation within an atmosphere should cause friction would should convert angular momentum into thermal loss. 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 p…

Energy conservation and momentum conservation are different
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