10 ms·

The laws of physics would dictate that this energy would come from somewhere. If enough power is generated, it will significantly alter the ocean flows dynamics

The laws of physics would dictate that this energy would come from somewhere. If enough power is generated, it will significantly alter the ocean flows dynamics. Deep ocean flow currents can very much affect the climate. Did anybody researched that this would be Ok?

samatman 4y ago
This is like worrying that wind turbines will stop the wind. They won't.
- enchiridion 4y ago
  No, it’s asking a question about our knowledge of the scale and power of the devices and forces involved. If it is a analog to wind turbines, the math will bear it out, but it’s a perfectly valid question to ask.
  - drieddust 4y ago
    Exactly just a few decades ago CFC was a non issue, Lead caused no harm, smoking was good for health, and cocaine was a refreshing drink. Yet here we are again so full of ourselves that asking the question is unsettling.
    - politician 4y ago
      So we should keep doing the known harmful power generation methods (coal) instead of experimenting with new methods (deep sea turbines) out of a diffuse fear of the unknown consequences? It’s sad that this is such a common argument against progress. Where do people learn to think this way? Does it come from education? Failures in life?
      - manigandham 4y ago
        Nobody said that. The concern is that more information should be discovered about the effects, and that is usually done through experimentation. > ”Where do people learn to think this way? ” Where do people learn to create straw man arguments instead of actually replying to what was said?
      - mintyDijon 4y ago
        Have you ever heard the saying: "The grass is always greener on the otherside." I believe that's where this line of thinking comes from. Have you ever tried to change lanes because yours isn't moving, just to find that right after you change to your new lane it stops and your old lane picks up again? Man that sucks
      - drieddust 4y ago
        Nopes move fast and break things. Only issue is that Earth is not a software system which can be fixed with upgrades.
- shiftpgdn 4y ago
  We’re arguing semantics but on a big enough scale they would eventually. That’s why you don’t just line up 100 of them directly next to eachother.
  - mattnewton 4y ago
    Agree that this is effectively arguing semantics, and it is taking energy from the wind. But the effect of each _is_ very small. There are definitely farms with >100 turbines close together. This one has >600 and has long runs of them close together. https://en.m.wikipedia.org/wiki/Alta_Wind_Energy_Center https://en.m.wikipedia.org/wiki/Alta_Wind_Energy_Center
    - weaksauce 4y ago
      while that one produces more electricity, this one has about twice as many turbines in close proximity: https://en.m.wikipedia.org/wiki/San_Gorgonio_Pass_wind_farm https://en.m.wikipedia.org/wiki/San_Gorgonio_Pass_wind_farm
- deleted 4y ago
  [deleted]
- xupybd 4y ago
  There is a scale that they would. We are orders of magnitude away from that scale. It's an interesting line of thinking to imagine the scale required to significantly change the winds.
throw457 4y ago
kube-system 4y ago
Flowing water has insane amounts of energy even in tiny amounts. I would imagine that this affects ocean currents as little or less than wind turbines affect weather patterns.
- Mindless2112 4y ago
  "It's so vast that small human actions couldn't possibly have an impact" is literally the same wrong-headed reasoning that leads people to believe that human CO₂ emissions don't matter. There seems to have been a lot of extreme weather in recent years. Could it be because harvesting energy from the wind alters weather patterns? A lot of people would rather just blame it on global warming than ask a question that might expose a flaw in our plans to wean ourselves off of fossil fuels. We need to have bit more humility and a bit less dogma about what we "know".
  - jeffbee 4y ago
    The mechanism by which CO2 raises the steady-state temperature of the atmosphere is well understood, and it is not because of the awesome power of CO2, it is because the Sun is incredibly energetic. By contrast, there is no known way that wind power extraction, which is currently < 1TW globally, could possibly be destabilizing the energy system of the rotation of the Earth (which is what causes wind). That system contains ten billion times more kinetic energy than we remove from it annually. The amount of kinetic energy the moon removes from the Earth's rotational kinetic energy every year is larger, and has been going on for a long, long time, so if it was going to cause fire weather that would already have been a long-standing problem. In short, the amount of CO2 that humans have dumped into the atmosphere in the last 200 years is comparable to the amount that was in there to begin with. It can't be ignored. But the amount of energy we remove from the wind is nine or ten orders of magnitude smaller than the total amount that exists, and therefore it can be ignored.
  - Dylan16807 4y ago
    The reason CO₂ emissions matter so much is that they accumulate over time. > There seems to have been a lot of extreme weather in recent years. Could it be because harvesting energy from the wind alters weather patterns? A lot of people would rather just blame it on global warming than ask a question that might expose a flaw in our plans to wean ourselves off of fossil fuels. Do you have anything other than wild speculation? Because in most cases slowing down air currents should calm the weather. And of course this has been asked!
deepsun 4y ago
It mostly comes from the Sun. It spews so much energy at Earth that all humanity consumption doesn't make a dent in it.
throwaway290 4y ago
Persistent deep ocean currents exist in large part thanks to temperature gradients (cf. AMOC and thermohaline circulation). Climate warming, melting ice and reducing these gradients, has much more drastic effects on ocean currents (cf. Gulf Stream weakening) than a turbine could ever have. Paradoxically, we would effectively be saving those currents using a fraction of the energy in those currents themselves. Using these turbines would be a drop in the ocean and a smart move if it helps us tackle the big offender. We should get on it soon though, if we let it get to a point where thermohaline circulation falls apart using currents this way may no longer be an option.
- mintyDijon 4y ago
  I aggree with the necessity of haste, but I hope these turbines can be developed in a way to have minimal impact on all the ocean life that uses these currents aswell, there's already so much damage thats been done to the ocean ecosystems already.
wcoenen 4y ago
The same could be said about wind power. Ultimately, wind and ocean currents are driven by the 170,000 terawatts of solar irradiance continuously hitting the earth[1]. Human civilization uses about 17 terawatt[2], so we still have a ways to go before we get in the same ballpark. (On the other hand, give it a few centuries of exponential growth and let's see where we end up.) [1] https://news.mit.edu/2011/energy-scale-part3-1026 https://news.mit.edu/2011/energy-scale-part3-1026 https://www.theworldcounts.com/stories/current_world_energy_consumption https://www.theworldcounts.com/stories/current_world_energy_... [2] https://www.theworldcounts.com/stories/current_world_energy_consumption https://www.theworldcounts.com/stories/current_world_energy_...
- user3939382 4y ago
  Just to point out, we would be harvesting a lot more than we use because of inefficiencies in capturing, storage, and transmission strategies. Also note that the amount we use is lower than it would otherwise be if we had access to more energy, industry is energy-constrained.
  - rootusrootus 4y ago
    In the case of something like PV, would that matter too much? The inefficiency doesn't mean the rest is lost, just that it stays in the local environment rather than get transmitted away somewhere else on a wire.
    - omgwtfbyobbq 4y ago
      Pretty much. As an examples, in deserts, there can be a modest increase in local IR radiation because of the change in albedo from PV panels compared to sand, but the overall decrease in IR from avoiding the CO2/etc emissions of fossil fuel generation is much, much larger than the local increase.
- neatze 4y ago
  This with assumption that there is linear relation without butterfly effects, even if there are negative effects, most likely they are negligible when compared to green house effect on the planet, my false intuition tells me that power generation from wind and ocean currents would contribute to planet cooling, no idea if electricity converted to work will radiate heat faster into space then air and oceans passively.
kache_ 4y ago
The energy harvested is only... a drop in the ocean :)
samwillis 4y ago
Other people will explain why you are wrong to be concerned. However your concern is indicative of the concerns of a significant, potentially majority, of people. It shows how as a society we don't do messaging about this sort of thing well enough. I think thats an important take away.
- politician 4y ago
  We do a bad job of explaining to residents of our dense population centers how much energy is required to run their city for a single day, where it comes from, and how much it costs to produce.
  - wumpus 4y ago
    Don't rural dwellers use more energy, per capita?
    - politician 4y ago
      Per capita is a poor way of looking at the scope of this particular problem. We can service that one farm with several thousand gallons of diesel. It’s an understandable power generation problem with units normal people understand. Powering a city is at another entirely different scale, and “diesel” doesn’t come close to addressing the magnitude of that problem.
- BurningFrog 4y ago
  To oversimplify, I think the default posture in western society has become "let's not do anything, in case it goes wrong". People who think like that are seen as serious people who don't foolishly ignore all possible negative consequences. I, as the reader might guess by now, don't have high hopes for societies that function this way.
  - salawat 4y ago
    Nooo... The default is "do your due diligence". As it turns out, there's a LOT more we can do now (that is actually hard work to boot) than we've necessarily been able to do before. If you actually take the phrase "reasonably forseeable" seriously, I assure you, chasing down those nasty little details and feeding them through the math takes a hot minute.
baybal2 4y ago
Is this out of the same ballpark as "thermal powerplants will boil the atmosphere." The entire humankind's power consumption is completely microscopic in comparison to any natural weather phenomena. We are 0.0000000000001% of energy the Earth dissipates.
- fooker 4y ago
  It is on the same ballpark, and that's exactly why it's worth discussing. Runaway effects in the same ballpark can easily become issues with a feedback loop mechanism. Interestingly this was a real concern before testing the first nuclear weapons. Some scientists were convinced that the chain reaction would ignite enough of a fraction of the atmosphere causing irreparable damage. That concern was ignored because these weapons were critical for the war, and luckily nothing like that ended up happening.
satokema 4y ago
the other way around is also true, the climate affects the flows seems like an interesting possibility to recapture some of the loose climate energy that we want to pare down
fasteo 4y ago
The same can be said about solar panels. An enormous amount of heat is no longer hitting the ground.
- libraryatnight 4y ago
  How significant a difference is it that previously it was hitting my roof?
- Klinky 4y ago
  The same can be said about humans. An enormous amount of heat is no longer hitting the ground due to man-made structures in general, way more than dedicated solar farms. Very likely putting solar on roofs is more beneficial than letting it just heat up tiles/shingles, while the building shades the ground. You're basically arguing against building civilization. However, I think human's effects on ecosystems is worthy of investigating, but the "solar panels blocking ground heat" concern seems very tangential and likely insignificant compared to the concerns of human's overall impacts on micro/macro environments.
slight_glitch 4y ago
I like the answers to your questions here. I wonder if in 100 years or so, our energy consumption won't be what 640K of memory (enough for anybody?) was around 1980. Time will tell if it will be a drop in the ocean then.
trebligdivad 4y ago
Maybe that would be good! If hurricanes are powered by hot seas, then removing energy from the seas has got to remove energy from hurrcianes?
fswd 4y ago
The energy comes from the moon orbiting the earth. Theoretically speaking, taking too much energy would cause the moon to come crashing down to Earth.
- anticensor 4y ago
  What about the compromise, the Moon in geostationary orbit: would be great for broadcasters (no more broadcast satellites, just plant antennas on the moon).
- Zababa 4y ago
  I've always wanted to have a bigger Moon, this might be a way to achieve that.
- Dylan16807 4y ago
  The tides are already transferring energy from the Earth to the Moon, making it go higher over time. I suspect that adding more drag to the tides could either boost this process or reduce it, depending on the timing of the energy harvesting.
- nradov 4y ago
  The energy in tidal currents comes both from the moon orbiting the Earth, and from the Earth orbiting the sun. (Technically other heavenly bodies also have some effect, but it's negligible.)
syntaxing 4y ago
True to a certain extent. People forget that Earth is not a zero sum control volume. We get a crap ton of energy from the Sun and the sun power most things on Earth in some shape or form (minus matter formation or radioactive material). The Earth uses around 23,900 terawatt-hours a year. The sun generates about 430 quintillion kWh every hour.
MR4D 4y ago
I would hazard a guess that the energy is ultimately from the moon circling the earth. Not sure how much physics has to scale to put that off balance, but other than damming up an ocean current, I can’t imagine we’d mess it up in the way you mention.
nsonha 4y ago
Research how? It's not like they can go from 0% to exhausting wave energy immediately. You'd think people will look into this as the technology grows, but you need the tech to actually be there to research it. I would also say I'm not a big fan of the activists' line of thinking that artificial changes in the ecosystem being bad (but man-made "conservative" actions are good). I mean you can't possibly prove that and we're way pass "should we alter our environment?"
perihelions 4y ago
I don't think there's really much energy in ocean currents. Based on the numbers from here [0], it seems you can get no more than 20 GW from the entirety of the Kuroshio current (the big one near Japan that they're targeting). That's not really a lot, and presumably the environmentally safe level is a fraction of that, after which you're fucking up heat transport on a planetary scale*. (Maximum flow of 65 sverdrups = 6.5e7 m³/s, and a top current speed under 1 m/s. Density of water is 1e3 kg/m³, and there's also a subtle multiplicative factor of 0.6, from Betz's law). [0] https://tos.org/oceanography/assets/docs/28-4_andres.pdf https://tos.org/oceanography/assets/docs/28-4_andres.pdf ("Mean Structure and Variability of the Kuroshio") https://en.wikipedia.org/wiki/Sverdrup https://en.wikipedia.org/wiki/Sverdrup https://en.wikipedia.org/wiki/Betz%27s_law https://en.wikipedia.org/wiki/Betz%27s_law *(Footnote because this stood out to me as weird, but the math holds up: the amount of heat energy transported in ocean currents is >10⁴ times greater than their kinetic energy (what ocean turbines can extract). 1 kg of water stores 4,200 J per 1 °C temperature increase, but only 0.5 J of kinetic energy at 1 m/s. So I think that blocking an ocean current would have a disproportionate amplifying effect on the climate. IANAO).
- perihelions 4y ago
  Appending to my comment: actual experts say the potential isn't 20 GW but 200 GW. I don't know where I made my error. https://www.bloomberg.com/news/features/2022-05-30/japan-s-deep-ocean-turbine-trial-offers-hope-of-phasing-out-fossil-fuels https://www.bloomberg.com/news/features/2022-05-30/japan-s-d... - "Japan’s New Energy and Industrial Technology Development Organization (NEDO) estimates the Kuroshio Current could potentially generate as much as 200 gigawatts"

samatman 4y ago

This is like worrying that wind turbines will stop the wind. They won't.

enchiridion 4y ago
No, it’s asking a question about our knowledge of the scale and power of the devices and forces involved. If it is a analog to wind turbines, the math will bear it out, but it’s a perfectly valid question to ask.
- drieddust 4y ago
  Exactly just a few decades ago CFC was a non issue, Lead caused no harm, smoking was good for health, and cocaine was a refreshing drink. Yet here we are again so full of ourselves that asking the question is unsettling.
  - politician 4y ago
    So we should keep doing the known harmful power generation methods (coal) instead of experimenting with new methods (deep sea turbines) out of a diffuse fear of the unknown consequences? It’s sad that this is such a common argument against progress. Where do people learn to think this way? Does it come from education? Failures in life?
    - manigandham 4y ago
      Nobody said that. The concern is that more information should be discovered about the effects, and that is usually done through experimentation. > ”Where do people learn to think this way? ” Where do people learn to create straw man arguments instead of actually replying to what was said?
    - mintyDijon 4y ago
      Have you ever heard the saying: "The grass is always greener on the otherside." I believe that's where this line of thinking comes from. Have you ever tried to change lanes because yours isn't moving, just to find that right after you change to your new lane it stops and your old lane picks up again? Man that sucks
    - drieddust 4y ago
      Nopes move fast and break things. Only issue is that Earth is not a software system which can be fixed with upgrades.
shiftpgdn 4y ago
We’re arguing semantics but on a big enough scale they would eventually. That’s why you don’t just line up 100 of them directly next to eachother.
- mattnewton 4y ago
  Agree that this is effectively arguing semantics, and it is taking energy from the wind. But the effect of each _is_ very small. There are definitely farms with >100 turbines close together. This one has >600 and has long runs of them close together. https://en.m.wikipedia.org/wiki/Alta_Wind_Energy_Center https://en.m.wikipedia.org/wiki/Alta_Wind_Energy_Center
  - weaksauce 4y ago
    while that one produces more electricity, this one has about twice as many turbines in close proximity: https://en.m.wikipedia.org/wiki/San_Gorgonio_Pass_wind_farm https://en.m.wikipedia.org/wiki/San_Gorgonio_Pass_wind_farm
deleted 4y ago
[deleted]
xupybd 4y ago
There is a scale that they would. We are orders of magnitude away from that scale. It's an interesting line of thinking to imagine the scale required to significantly change the winds.

throw457 4y ago

kube-system 4y ago

Flowing water has insane amounts of energy even in tiny amounts. I would imagine that this affects ocean currents as little or less than wind turbines affect weather patterns.

Mindless2112 4y ago
"It's so vast that small human actions couldn't possibly have an impact" is literally the same wrong-headed reasoning that leads people to believe that human CO₂ emissions don't matter. There seems to have been a lot of extreme weather in recent years. Could it be because harvesting energy from the wind alters weather patterns? A lot of people would rather just blame it on global warming than ask a question that might expose a flaw in our plans to wean ourselves off of fossil fuels. We need to have bit more humility and a bit less dogma about what we "know".
- jeffbee 4y ago
  The mechanism by which CO2 raises the steady-state temperature of the atmosphere is well understood, and it is not because of the awesome power of CO2, it is because the Sun is incredibly energetic. By contrast, there is no known way that wind power extraction, which is currently < 1TW globally, could possibly be destabilizing the energy system of the rotation of the Earth (which is what causes wind). That system contains ten billion times more kinetic energy than we remove from it annually. The amount of kinetic energy the moon removes from the Earth's rotational kinetic energy every year is larger, and has been going on for a long, long time, so if it was going to cause fire weather that would already have been a long-standing problem. In short, the amount of CO2 that humans have dumped into the atmosphere in the last 200 years is comparable to the amount that was in there to begin with. It can't be ignored. But the amount of energy we remove from the wind is nine or ten orders of magnitude smaller than the total amount that exists, and therefore it can be ignored.
- Dylan16807 4y ago
  The reason CO₂ emissions matter so much is that they accumulate over time. > There seems to have been a lot of extreme weather in recent years. Could it be because harvesting energy from the wind alters weather patterns? A lot of people would rather just blame it on global warming than ask a question that might expose a flaw in our plans to wean ourselves off of fossil fuels. Do you have anything other than wild speculation? Because in most cases slowing down air currents should calm the weather. And of course this has been asked!

deepsun 4y ago

It mostly comes from the Sun. It spews so much energy at Earth that all humanity consumption doesn't make a dent in it.

throwaway290 4y ago

Persistent deep ocean currents exist in large part thanks to temperature gradients (cf. AMOC and thermohaline circulation). Climate warming, melting ice and reducing these gradients, has much more drastic effects on ocean currents (cf. Gulf Stream weakening) than a turbine could ever have. Paradoxically, we would effectively be saving those currents using a fraction of the energy in those currents themselves. Using these turbines would be a drop in the ocean and a smart move if it helps us tackle the big offender. We should get on it soon though, if we let it get to a point where thermohaline circulation falls apart using currents this way may no longer be an option.

mintyDijon 4y ago
I aggree with the necessity of haste, but I hope these turbines can be developed in a way to have minimal impact on all the ocean life that uses these currents aswell, there's already so much damage thats been done to the ocean ecosystems already.

wcoenen 4y ago

The same could be said about wind power. Ultimately, wind and ocean currents are driven by the 170,000 terawatts of solar irradiance continuously hitting the earth[1]. Human civilization uses about 17 terawatt[2], so we still have a ways to go before we get in the same ballpark. (On the other hand, give it a few centuries of exponential growth and let's see where we end up.) [1] https://news.mit.edu/2011/energy-scale-part3-1026 https://news.mit.edu/2011/energy-scale-part3-1026 https://www.theworldcounts.com/stories/current_world_energy_consumption https://www.theworldcounts.com/stories/current_world_energy_... [2] https://www.theworldcounts.com/stories/current_world_energy_consumption https://www.theworldcounts.com/stories/current_world_energy_...

user3939382 4y ago
Just to point out, we would be harvesting a lot more than we use because of inefficiencies in capturing, storage, and transmission strategies. Also note that the amount we use is lower than it would otherwise be if we had access to more energy, industry is energy-constrained.
- rootusrootus 4y ago
  In the case of something like PV, would that matter too much? The inefficiency doesn't mean the rest is lost, just that it stays in the local environment rather than get transmitted away somewhere else on a wire.
  - omgwtfbyobbq 4y ago
    Pretty much. As an examples, in deserts, there can be a modest increase in local IR radiation because of the change in albedo from PV panels compared to sand, but the overall decrease in IR from avoiding the CO2/etc emissions of fossil fuel generation is much, much larger than the local increase.
neatze 4y ago
This with assumption that there is linear relation without butterfly effects, even if there are negative effects, most likely they are negligible when compared to green house effect on the planet, my false intuition tells me that power generation from wind and ocean currents would contribute to planet cooling, no idea if electricity converted to work will radiate heat faster into space then air and oceans passively.

kache_ 4y ago

The energy harvested is only... a drop in the ocean :)

samwillis 4y ago

Other people will explain why you are wrong to be concerned. However your concern is indicative of the concerns of a significant, potentially majority, of people. It shows how as a society we don't do messaging about this sort of thing well enough. I think thats an important take away.

politician 4y ago
We do a bad job of explaining to residents of our dense population centers how much energy is required to run their city for a single day, where it comes from, and how much it costs to produce.
- wumpus 4y ago
  Don't rural dwellers use more energy, per capita?
  - politician 4y ago
    Per capita is a poor way of looking at the scope of this particular problem. We can service that one farm with several thousand gallons of diesel. It’s an understandable power generation problem with units normal people understand. Powering a city is at another entirely different scale, and “diesel” doesn’t come close to addressing the magnitude of that problem.
BurningFrog 4y ago
To oversimplify, I think the default posture in western society has become "let's not do anything, in case it goes wrong". People who think like that are seen as serious people who don't foolishly ignore all possible negative consequences. I, as the reader might guess by now, don't have high hopes for societies that function this way.
- salawat 4y ago
  Nooo... The default is "do your due diligence". As it turns out, there's a LOT more we can do now (that is actually hard work to boot) than we've necessarily been able to do before. If you actually take the phrase "reasonably forseeable" seriously, I assure you, chasing down those nasty little details and feeding them through the math takes a hot minute.

baybal2 4y ago

Is this out of the same ballpark as "thermal powerplants will boil the atmosphere." The entire humankind's power consumption is completely microscopic in comparison to any natural weather phenomena. We are 0.0000000000001% of energy the Earth dissipates.

fooker 4y ago
It is on the same ballpark, and that's exactly why it's worth discussing. Runaway effects in the same ballpark can easily become issues with a feedback loop mechanism. Interestingly this was a real concern before testing the first nuclear weapons. Some scientists were convinced that the chain reaction would ignite enough of a fraction of the atmosphere causing irreparable damage. That concern was ignored because these weapons were critical for the war, and luckily nothing like that ended up happening.

satokema 4y ago

the other way around is also true, the climate affects the flows seems like an interesting possibility to recapture some of the loose climate energy that we want to pare down

fasteo 4y ago

The same can be said about solar panels. An enormous amount of heat is no longer hitting the ground.

libraryatnight 4y ago
How significant a difference is it that previously it was hitting my roof?
Klinky 4y ago
The same can be said about humans. An enormous amount of heat is no longer hitting the ground due to man-made structures in general, way more than dedicated solar farms. Very likely putting solar on roofs is more beneficial than letting it just heat up tiles/shingles, while the building shades the ground. You're basically arguing against building civilization. However, I think human's effects on ecosystems is worthy of investigating, but the "solar panels blocking ground heat" concern seems very tangential and likely insignificant compared to the concerns of human's overall impacts on micro/macro environments.

slight_glitch 4y ago

I like the answers to your questions here. I wonder if in 100 years or so, our energy consumption won't be what 640K of memory (enough for anybody?) was around 1980. Time will tell if it will be a drop in the ocean then.

trebligdivad 4y ago

Maybe that would be good! If hurricanes are powered by hot seas, then removing energy from the seas has got to remove energy from hurrcianes?

fswd 4y ago

The energy comes from the moon orbiting the earth. Theoretically speaking, taking too much energy would cause the moon to come crashing down to Earth.

anticensor 4y ago
What about the compromise, the Moon in geostationary orbit: would be great for broadcasters (no more broadcast satellites, just plant antennas on the moon).
Zababa 4y ago
I've always wanted to have a bigger Moon, this might be a way to achieve that.
Dylan16807 4y ago
The tides are already transferring energy from the Earth to the Moon, making it go higher over time. I suspect that adding more drag to the tides could either boost this process or reduce it, depending on the timing of the energy harvesting.
nradov 4y ago
The energy in tidal currents comes both from the moon orbiting the Earth, and from the Earth orbiting the sun. (Technically other heavenly bodies also have some effect, but it's negligible.)

syntaxing 4y ago

True to a certain extent. People forget that Earth is not a zero sum control volume. We get a crap ton of energy from the Sun and the sun power most things on Earth in some shape or form (minus matter formation or radioactive material). The Earth uses around 23,900 terawatt-hours a year. The sun generates about 430 quintillion kWh every hour.

MR4D 4y ago

I would hazard a guess that the energy is ultimately from the moon circling the earth. Not sure how much physics has to scale to put that off balance, but other than damming up an ocean current, I can’t imagine we’d mess it up in the way you mention.

nsonha 4y ago

Research how? It's not like they can go from 0% to exhausting wave energy immediately. You'd think people will look into this as the technology grows, but you need the tech to actually be there to research it. I would also say I'm not a big fan of the activists' line of thinking that artificial changes in the ecosystem being bad (but man-made "conservative" actions are good). I mean you can't possibly prove that and we're way pass "should we alter our environment?"

perihelions 4y ago

I don't think there's really much energy in ocean currents. Based on the numbers from here [0], it seems you can get no more than 20 GW from the entirety of the Kuroshio current (the big one near Japan that they're targeting). That's not really a lot, and presumably the environmentally safe level is a fraction of that, after which you're fucking up heat transport on a planetary scale*. (Maximum flow of 65 sverdrups = 6.5e7 m³/s, and a top current speed under 1 m/s. Density of water is 1e3 kg/m³, and there's also a subtle multiplicative factor of 0.6, from Betz's law). [0] https://tos.org/oceanography/assets/docs/28-4_andres.pdf https://tos.org/oceanography/assets/docs/28-4_andres.pdf ("Mean Structure and Variability of the Kuroshio") https://en.wikipedia.org/wiki/Sverdrup https://en.wikipedia.org/wiki/Sverdrup https://en.wikipedia.org/wiki/Betz%27s_law https://en.wikipedia.org/wiki/Betz%27s_law *(Footnote because this stood out to me as weird, but the math holds up: the amount of heat energy transported in ocean currents is >10⁴ times greater than their kinetic energy (what ocean turbines can extract). 1 kg of water stores 4,200 J per 1 °C temperature increase, but only 0.5 J of kinetic energy at 1 m/s. So I think that blocking an ocean current would have a disproportionate amplifying effect on the climate. IANAO).

perihelions 4y ago
Appending to my comment: actual experts say the potential isn't 20 GW but 200 GW. I don't know where I made my error. https://www.bloomberg.com/news/features/2022-05-30/japan-s-deep-ocean-turbine-trial-offers-hope-of-phasing-out-fossil-fuels https://www.bloomberg.com/news/features/2022-05-30/japan-s-d... - "Japan’s New Energy and Industrial Technology Development Organization (NEDO) estimates the Kuroshio Current could potentially generate as much as 200 gigawatts"