Re: [geo] Wind and wave energies are not renewable after all
Hi David, Couple of questions. Generation of wind energy would increase the KE dissipation rate but this is not an external forcing to the climate system. I agree there would be local and regional climate changes but there should be no global mean warming. Right? The current KE dissipation rate is about 2 watts/m^2. Over land, this translates to about 300 TW. Suppose wind farms extract 150 TW (which may be impractical), the dissipation rate over land will increase to 3 Wm^2. Don't you think the KE (or available PE) generation rate in the atmosphere would correspondingly increase? Of course these would be large regional climate changes. Bala On Tue, Jul 12, 2011 at 8:37 AM, David Keith ke...@ucalgary.ca wrote: Responding to a VERY old thread on wind power: ** ** *The only link to geoengineering here is that there is a possibility of manipulating wind turbine drag for weather control, see: * ** ** At 10’s TW scale extraction of wind does begin to be constrained by the generation of kinetic energy. I led the a joint NCAR-GFDL group that published the first paper on this topic see: David W. Keith et al, The influence of large-scale wind-power on global climate. *Proceedings of the National* *Academy* *of Sciences*, *101*, p. 16115-16120. http://people.ucalgary.ca/~keith/papers/66.Keith.2004.WindAndClimate.e.pdf ** ** See http://people.ucalgary.ca/~keith/papers/94.Kirk-Davidoff.SurfaceRoughnessJAS.p.pdffor a paper that says a bit about why it happens. ** ** The following web page gives and overview but it’s now out of date: http://people.ucalgary.ca/~keith/wind.html ** ** Alvia’s comment that about “kinetic energy, i.e. the motion of molecules”, confuses the physics. Kinetic energy is *macroscopic* velocity, random motion of molecules is just heat. It is true that large scale production and dissipation of kinetic energy must balance, have a look at Peixoto and Oort’s the *Physics of Climate* or a short encyclopedia article I one wrote on atmospheric energetics: http://people.ucalgary.ca/~keith/papers/15.Keith.1996.Energetics.s.pdf *** * ** ** Bottom lines: ** ** 1. Commonly cited estimates for global wind power potential are too large. On cannot get to 100 TW in any practical scheme I know about. ** ** 2. At even a few TW large scale climate effects will begin to be important. But, this does not say we should not make a few TW of wind, just that--like any energy technology—there are tradeoffs. ** ** David ** ** *From:* geoengineering@googlegroups.com [mailto: geoengineering@googlegroups.com] *On Behalf Of *Nando *Sent:* Saturday, April 02, 2011 8:25 AM *To:* agask...@nc.rr.com *Cc:* andrew.lock...@gmail.com; geoengineering *Subject:* Re: [geo] Wind and wave energies are not renewable after all*** * ** ** My reading of the article suggested that the authors of the study were principally claiming that wind has an impact on climate, so it is already being used. What wasn't clear from the article was *what type* of impact reducing the energy level of winds all over the globe through the prolific use of wind turbines might have. In a warming world, I understand we should expect stronger winds. On a simplistic generalized level that might not be relevant to local climate, slowing those stronger winds down might have an ameliorating effect on climate change. Hence the claim that *The magnitude of the changes was comparable to the changes to the climate caused by doubling atmospheric concentrations of carbon dioxide* might not be as bad as it is made to seem. ** ** As usually, I'm grasping at straws, but as a layman, that's what stood out for me. ** ** Nando On Sat, Apr 2, 2011 at 3:15 PM, Alvia Gaskill agask...@nc.rr.com wrote:* *** Wind and wave energy are the result of the conversion of solar energy into kinetic energy, i.e. the motion of molecules. Once converted into kinetic energy it's a use it or lose it proposition. Extracting kinetic energy from the atmosphere or the ocean doesn't mean it won't be replaced by more energy from sunlight. Planting more trees will also intercept winds, albeit without the electricity generation. Who funded this research? The same people who want to prevent contact with alien civilizations? I note that the Royal Society was also a party to that one too. Note to Royal Society. When you actually find something under the bed I should be afraid of, wake me up. - Original Message - *From:* Andrew Lockley and...@andrewlockley.com *To:* geoengineering geoengineering@googlegroups.com *Sent:* Friday, April 01, 2011 8:10 *Subject:* [geo] Wind and wave energies are not renewable after all ** ** Wind and wave energies are not renewable after all **· **30 March 2011 by *Mark Buchanan*http://www.newscientist.com/search?rbauthors=Mark+Buchanan
Re: [geo] Wind and wave energies are not renewable after all
Dear David--I was going to ask a similar question to Bala¹s‹as this has actually been an ongoing argument in some circles of the energy community, with a scientific study by a Royal Society lead physicist in their energy analysis talking about a limit based on extracting a share of the existing atmospheric KE and Mark Jacobson at Stanford saying there is plenty of KE as it will be restored. It seems to me that the KE pulled out will be replaced‹if not, the atmosphere would eventually not be moving and so a huge equator-pole temperature gradient would build up. With solar energy concentrated at the low latitudes and IR loss in excess at high latitudes, the atmosphere will be seeking balance; take some energy out and the atmosphere will try to restore it, rather like what happens when one puts a rock in a stream, maybe with a bit different flow, but I would not think significantly less KE. Right? Mike On 7/12/11 7:25 AM, Govindasamy Bala bala@gmail.com wrote: Hi David, Couple of questions. Generation of wind energy would increase the KE dissipation rate but this is not an external forcing to the climate system. I agree there would be local and regional climate changes but there should be no global mean warming. Right? The current KE dissipation rate is about 2 watts/m^2. Over land, this translates to about 300 TW. Suppose wind farms extract 150 TW (which may be impractical), the dissipation rate over land will increase to 3 Wm^2. Don't you think the KE (or available PE) generation rate in the atmosphere would correspondingly increase? Of course these would be large regional climate changes. Bala On Tue, Jul 12, 2011 at 8:37 AM, David Keith ke...@ucalgary.ca wrote: Responding to a VERY old thread on wind power: The only link to geoengineering here is that there is a possibility of manipulating wind turbine drag for weather control, see: At 10¹s TW scale extraction of wind does begin to be constrained by the generation of kinetic energy. I led the a joint NCAR-GFDL group that published the first paper on this topic see: David W. Keith et al, The influence of large-scale wind-power on global climate. Proceedings of the National Academy of Sciences, 101, p. 16115-16120. http://people.ucalgary.ca/~keith/papers/66.Keith.2004.WindAndClimate.e.pdf http://people.ucalgary.ca/%7Ekeith/papers/66.Keith.2004.WindAndClimate.e.pdf See http://people.ucalgary.ca/~keith/papers/94.Kirk-Davidoff.SurfaceRoughnessJAS. p.pdf http://people.ucalgary.ca/%7Ekeith/papers/94.Kirk-Davidoff.SurfaceRoughnessJ AS.p.pdf for a paper that says a bit about why it happens. The following web page gives and overview but it¹s now out of date: http://people.ucalgary.ca/~keith/wind.html http://people.ucalgary.ca/%7Ekeith/wind.html Alvia¹s comment that about ³kinetic energy, i.e. the motion of molecules², confuses the physics. Kinetic energy is macroscopic velocity, random motion of molecules is just heat. It is true that large scale production and dissipation of kinetic energy must balance, have a look at Peixoto and Oort¹s the Physics of Climate or a short encyclopedia article I one wrote on atmospheric energetics: http://people.ucalgary.ca/~keith/papers/15.Keith.1996.Energetics.s.pdf http://people.ucalgary.ca/%7Ekeith/papers/15.Keith.1996.Energetics.s.pdf Bottom lines: 1. Commonly cited estimates for global wind power potential are too large. On cannot get to 100 TW in any practical scheme I know about. 2. At even a few TW large scale climate effects will begin to be important. But, this does not say we should not make a few TW of wind, just that--like any energy technology‹there are tradeoffs. David From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] On Behalf Of Nando Sent: Saturday, April 02, 2011 8:25 AM To: agask...@nc.rr.com Cc: andrew.lock...@gmail.com; geoengineering Subject: Re: [geo] Wind and wave energies are not renewable after all My reading of the article suggested that the authors of the study were principally claiming that wind has an impact on climate, so it is already being used. What wasn't clear from the article was what type of impact reducing the energy level of winds all over the globe through the prolific use of wind turbines might have. In a warming world, I understand we should expect stronger winds. On a simplistic generalized level that might not be relevant to local climate, slowing those stronger winds down might have an ameliorating effect on climate change. Hence the claim that The magnitude of the changes was comparable to the changes to the climate caused by doubling atmospheric concentrations of carbon dioxide might not be as bad as it is made to seem. As usually, I'm grasping at straws, but as a layman, that's what stood out for me. Nando On Sat, Apr 2, 2011 at 3:15 PM, Alvia Gaskill agask...@nc.rr.com wrote: Wind and wave energy
Re: [geo] Wind and wave energies are not renewable after all
If anything, an obstruction or impediment to fluid flows resulting from wind energy extraction will tend to reduce heat redistribution, and that will help restore the temperature differential between tropics and poles which has been harmed by the polar amplification of global warming Logically, it will help to restore the polar ice, or at least prevent it from retreating further as fast. It could even help maintain ocean circulation, and help prevent an anoxic event. A On 12 Jul 2011 13:22, Mike MacCracken mmacc...@comcast.net wrote: Dear David--I was going to ask a similar question to Bala¹s‹as this has actually been an ongoing argument in some circles of the energy community, with a scientific study by a Royal Society lead physicist in their energy analysis talking about a limit based on extracting a share of the existing atmospheric KE and Mark Jacobson at Stanford saying there is plenty of KE as it will be restored. It seems to me that the KE pulled out will be replaced‹if not, the atmosphere would eventually not be moving and so a huge equator-pole temperature gradient would build up. With solar energy concentrated at the low latitudes and IR loss in excess at high latitudes, the atmosphere will be seeking balance; take some energy out and the atmosphere will try to restore it, rather like what happens when one puts a rock in a stream, maybe with a bit different flow, but I would not think significantly less KE. Right? Mike On 7/12/11 7:25 AM, Govindasamy Bala bala@gmail.com wrote: Hi David, Couple of questions. Generation of wind energy would increase the KE dissipation rate but this is not an external forcing to the climate system. I agree there would be local and regional climate changes but there should be no global mean warming. Right? The current KE dissipation rate is about 2 watts/m^2. Over land, this translates to about 300 TW. Suppose wind farms extract 150 TW (which may be impractical), the dissipation rate over land will increase to 3 Wm^2. Don't you think the KE (or available PE) generation rate in the atmosphere would correspondingly increase? Of course these would be large regional climate changes. Bala On Tue, Jul 12, 2011 at 8:37 AM, David Keith ke...@ucalgary.ca wrote: Responding to a VERY old thread on wind power: The only link to geoengineering here is that there is a possibility of manipulating wind turbine drag for weather control, see: At 10¹s TW scale extraction of wind does begin to be constrained by the generation of kinetic energy. I led the a joint NCAR-GFDL group that published the first paper on this topic see: David W. Keith et al, The influence of large-scale wind-power on global climate. Proceedings of the National Academy of Sciences, 101, p. 16115-16120. http://people.ucalgary.ca/~keith/papers/66.Keith.2004.WindAndClimate.e.pdf http://people.ucalgary.ca/%7Ekeith/papers/66.Keith.2004.WindAndClimate.e.pdf See http://people.ucalgary.ca/~keith/papers/94.Kirk-Davidoff.SurfaceRoughnessJAS . p.pdf http://people.ucalgary.ca/%7Ekeith/papers/94.Kirk-Davidoff.SurfaceRoughnessJ AS.p.pdf for a paper that says a bit about why it happens. The following web page gives and overview but it¹s now out of date: http://people.ucalgary.ca/~keith/wind.html http://people.ucalgary.ca/%7Ekeith/wind.html Alvia¹s comment that about ³kinetic energy, i.e. the motion of molecules², confuses the physics. Kinetic energy is macroscopic velocity, random motion of molecules is just heat. It is true that large scale production and dissipation of kinetic energy must balance, have a look at Peixoto and Oort¹s the Physics of Climate or a short encyclopedia article I one wrote on atmospheric energetics: http://people.ucalgary.ca/~keith/papers/15.Keith.1996.Energetics.s.pdf http://people.ucalgary.ca/%7Ekeith/papers/15.Keith.1996.Energetics.s.pdf Bottom lines: 1. Commonly cited estimates for global wind power potential are too large. On cannot get to 100 TW in any practical scheme I know about. 2. At even a few TW large scale climate effects will begin to be important. But, this does not say we should not make a few TW of wind, just that--like any energy technology‹there are tradeoffs. David From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] On Behalf Of Nando Sent: Saturday, April 02, 2011 8:25 AM To: agask...@nc.rr.com Cc: andrew.lock...@gmail.com; geoengineering Subject: Re: [geo] Wind and wave energies are not renewable after all My reading of the article suggested that the authors of the study were principally claiming that wind has an impact on climate, so it is already being used. What wasn't clear from the article was what type of impact reducing the energy level of winds all over the globe through the prolific use of wind turbines might have. In a warming world, I understand we should expect stronger winds. On a simplistic generalized level that might
RE: [geo] Wind and wave energies are not renewable after all
Mike Bala A few answers: First there is almost no link to geo here so we should probably take this off this list. The only (weak link) is weather control, see: http://www.atmos-chem-phys.org/10/769/2010/acp-10-769-2010.html 1. Bala said Generation of wind energy would increase the KE dissipation rate but this is not an external forcing to the climate system. And The current KE dissipation rate is about 2 watts/m^2. Over land, this translates to about 300 TW. Suppose wind farms extract 150 TW (which may be impractical), the dissipation rate over land will increase to 3 Wm^2. Don't you think the KE (or available PE) generation rate in the atmosphere would correspondingly increase? Of course these would be large regional climate changes. Answer: As the surface drag is increased the total dissipation does not change much. That is, as you increase the KE sink in some locations with wind turbines the dissipation decreases elsewhere keeping total about constant. See Figure 2 of our 2004 PNAS where we tried this. This is what one would expect because dissipation of KE must balance its creation from APE (see pexoto and ort or my encyclopedia article cited below for an overview of atmo energetics). Going a bit deeper one might think that with more to push against the APE generation rate would go up and the atmo heat engine get more efficient, Kerry Emanuel have suggested to me that this should not be true because of a maximum entropy principle that I do not fully understand. Bottom line: very likely Bala's assumption is wrong. 2. Bala said: I agree there would be local and regional climate changes but there should be no global mean warming. Right? Answer: mostly. One can see either warming or cooling depending on where the wind drag is applied. The point is that (a) climate changes due to drag are non-local, and (b) they can be large. 3. Mike asked about the Jacobsen paper that says no effect. Answer: I think this paper is just wrong. If it were true I could violate the first law by extracting power without altering KE and then using that power to increase APE generating infinite power with no input. Nice trick. There are now about 5 studies that confirm the broad results in our 2004 paper. The Jacobsen paper is an outlier. I expect a convincing critique will be published in the next few years. Yours, David From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] On Behalf Of Mike MacCracken Sent: Tuesday, July 12, 2011 6:22 AM To: Govindasamy Bala; David Keith; Ken Caldeira Cc: Geoengineering Subject: Re: [geo] Wind and wave energies are not renewable after all Dear David--I was going to ask a similar question to Bala's-as this has actually been an ongoing argument in some circles of the energy community, with a scientific study by a Royal Society lead physicist in their energy analysis talking about a limit based on extracting a share of the existing atmospheric KE and Mark Jacobson at Stanford saying there is plenty of KE as it will be restored. It seems to me that the KE pulled out will be replaced-if not, the atmosphere would eventually not be moving and so a huge equator-pole temperature gradient would build up. With solar energy concentrated at the low latitudes and IR loss in excess at high latitudes, the atmosphere will be seeking balance; take some energy out and the atmosphere will try to restore it, rather like what happens when one puts a rock in a stream, maybe with a bit different flow, but I would not think significantly less KE. Right? Mike On 7/12/11 7:25 AM, Govindasamy Bala bala@gmail.com wrote: Hi David, Couple of questions. Generation of wind energy would increase the KE dissipation rate but this is not an external forcing to the climate system. I agree there would be local and regional climate changes but there should be no global mean warming. Right? The current KE dissipation rate is about 2 watts/m^2. Over land, this translates to about 300 TW. Suppose wind farms extract 150 TW (which may be impractical), the dissipation rate over land will increase to 3 Wm^2. Don't you think the KE (or available PE) generation rate in the atmosphere would correspondingly increase? Of course these would be large regional climate changes. Bala On Tue, Jul 12, 2011 at 8:37 AM, David Keith ke...@ucalgary.ca wrote: Responding to a VERY old thread on wind power: The only link to geoengineering here is that there is a possibility of manipulating wind turbine drag for weather control, see: At 10's TW scale extraction of wind does begin to be constrained by the generation of kinetic energy. I led the a joint NCAR-GFDL group that published the first paper on this topic see: David W. Keith et al, The influence of large-scale wind-power on global climate. Proceedings of the National Academy of Sciences, 101, p. 16115-16120. http://people.ucalgary.ca/~keith/papers/66.Keith.2004.WindAndClimate.e.pdf http
Re: [geo] Wind and wave energies are not renewable after all
: Geoengineering Subject: Re: [geo] Wind and wave energies are not renewable after all Dear David--I was going to ask a similar question to Bala¹s‹as this has actually been an ongoing argument in some circles of the energy community, with a scientific study by a Royal Society lead physicist in their energy analysis talking about a limit based on extracting a share of the existing atmospheric KE and Mark Jacobson at Stanford saying there is plenty of KE as it will be restored. It seems to me that the KE pulled out will be replaced‹if not, the atmosphere would eventually not be moving and so a huge equator-pole temperature gradient would build up. With solar energy concentrated at the low latitudes and IR loss in excess at high latitudes, the atmosphere will be seeking balance; take some energy out and the atmosphere will try to restore it, rather like what happens when one puts a rock in a stream, maybe with a bit different flow, but I would not think significantly less KE. Right? Mike On 7/12/11 7:25 AM, Govindasamy Bala bala@gmail.com wrote: Hi David, Couple of questions. Generation of wind energy would increase the KE dissipation rate but this is not an external forcing to the climate system. I agree there would be local and regional climate changes but there should be no global mean warming. Right? The current KE dissipation rate is about 2 watts/m^2. Over land, this translates to about 300 TW. Suppose wind farms extract 150 TW (which may be impractical), the dissipation rate over land will increase to 3 Wm^2. Don't you think the KE (or available PE) generation rate in the atmosphere would correspondingly increase? Of course these would be large regional climate changes. Bala On Tue, Jul 12, 2011 at 8:37 AM, David Keith ke...@ucalgary.ca wrote: Responding to a VERY old thread on wind power: The only link to geoengineering here is that there is a possibility of manipulating wind turbine drag for weather control, see: At 10¹s TW scale extraction of wind does begin to be constrained by the generation of kinetic energy. I led the a joint NCAR-GFDL group that published the first paper on this topic see: David W. Keith et al, The influence of large-scale wind-power on global climate. Proceedings of the National Academy of Sciences, 101, p. 16115-16120. http://people.ucalgary.ca/~keith/papers/66.Keith.2004.WindAndClimate.e.pdf http://people.ucalgary.ca/%7Ekeith/papers/66.Keith.2004.WindAndClimate.e.pdf See http://people.ucalgary.ca/~keith/papers/94.Kirk-Davidoff.SurfaceRoughnessJAS.p .pdf http://people.ucalgary.ca/%7Ekeith/papers/94.Kirk-Davidoff.SurfaceRoughnessJA S.p.pdf for a paper that says a bit about why it happens. The following web page gives and overview but it¹s now out of date: http://people.ucalgary.ca/~keith/wind.html http://people.ucalgary.ca/%7Ekeith/wind.html Alvia¹s comment that about ³kinetic energy, i.e. the motion of molecules², confuses the physics. Kinetic energy is macroscopic velocity, random motion of molecules is just heat. It is true that large scale production and dissipation of kinetic energy must balance, have a look at Peixoto and Oort¹s the Physics of Climate or a short encyclopedia article I one wrote on atmospheric energetics: http://people.ucalgary.ca/~keith/papers/15.Keith.1996.Energetics.s.pdf http://people.ucalgary.ca/%7Ekeith/papers/15.Keith.1996.Energetics.s.pdf Bottom lines: 1. Commonly cited estimates for global wind power potential are too large. On cannot get to 100 TW in any practical scheme I know about. 2. At even a few TW large scale climate effects will begin to be important. But, this does not say we should not make a few TW of wind, just that--like any energy technology‹there are tradeoffs. David From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] On Behalf Of Nando Sent: Saturday, April 02, 2011 8:25 AM To: agask...@nc.rr.com Cc: andrew.lock...@gmail.com; geoengineering Subject: Re: [geo] Wind and wave energies are not renewable after all My reading of the article suggested that the authors of the study were principally claiming that wind has an impact on climate, so it is already being used. What wasn't clear from the article was what type of impact reducing the energy level of winds all over the globe through the prolific use of wind turbines might have. In a warming world, I understand we should expect stronger winds. On a simplistic generalized level that might not be relevant to local climate, slowing those stronger winds down might have an ameliorating effect on climate change. Hence the claim that The magnitude of the changes was comparable to the changes to the climate caused by doubling atmospheric concentrations of carbon dioxide might not be as bad as it is made to seem. As usually, I'm grasping at straws, but as a layman, that's what stood out for me. Nando On Sat
RE: [geo] Wind and wave energies are not renewable after all
Responding to a VERY old thread on wind power: The only link to geoengineering here is that there is a possibility of manipulating wind turbine drag for weather control, see: At 10's TW scale extraction of wind does begin to be constrained by the generation of kinetic energy. I led the a joint NCAR-GFDL group that published the first paper on this topic see: David W. Keith et al, The influence of large-scale wind-power on global climate. Proceedings of the National Academy of Sciences, 101, p. 16115-16120. http://people.ucalgary.ca/~keith/papers/66.Keith.2004.WindAndClimate.e.pdf See http://people.ucalgary.ca/~keith/papers/94.Kirk-Davidoff.SurfaceRoughnessJAS.p.pdf for a paper that says a bit about why it happens. The following web page gives and overview but it's now out of date: http://people.ucalgary.ca/~keith/wind.html Alvia's comment that about kinetic energy, i.e. the motion of molecules, confuses the physics. Kinetic energy is macroscopic velocity, random motion of molecules is just heat. It is true that large scale production and dissipation of kinetic energy must balance, have a look at Peixoto and Oort's the Physics of Climate or a short encyclopedia article I one wrote on atmospheric energetics: http://people.ucalgary.ca/~keith/papers/15.Keith.1996.Energetics.s.pdf Bottom lines: 1. Commonly cited estimates for global wind power potential are too large. On cannot get to 100 TW in any practical scheme I know about. 2. At even a few TW large scale climate effects will begin to be important. But, this does not say we should not make a few TW of wind, just that--like any energy technology-there are tradeoffs. David From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] On Behalf Of Nando Sent: Saturday, April 02, 2011 8:25 AM To: agask...@nc.rr.com Cc: andrew.lock...@gmail.com; geoengineering Subject: Re: [geo] Wind and wave energies are not renewable after all My reading of the article suggested that the authors of the study were principally claiming that wind has an impact on climate, so it is already being used. What wasn't clear from the article was what type of impact reducing the energy level of winds all over the globe through the prolific use of wind turbines might have. In a warming world, I understand we should expect stronger winds. On a simplistic generalized level that might not be relevant to local climate, slowing those stronger winds down might have an ameliorating effect on climate change. Hence the claim that The magnitude of the changes was comparable to the changes to the climate caused by doubling atmospheric concentrations of carbon dioxide might not be as bad as it is made to seem. As usually, I'm grasping at straws, but as a layman, that's what stood out for me. Nando On Sat, Apr 2, 2011 at 3:15 PM, Alvia Gaskill agask...@nc.rr.commailto:agask...@nc.rr.com wrote: Wind and wave energy are the result of the conversion of solar energy into kinetic energy, i.e. the motion of molecules. Once converted into kinetic energy it's a use it or lose it proposition. Extracting kinetic energy from the atmosphere or the ocean doesn't mean it won't be replaced by more energy from sunlight. Planting more trees will also intercept winds, albeit without the electricity generation. Who funded this research? The same people who want to prevent contact with alien civilizations? I note that the Royal Society was also a party to that one too. Note to Royal Society. When you actually find something under the bed I should be afraid of, wake me up. - Original Message - From: Andrew Lockleymailto:and...@andrewlockley.com To: geoengineeringmailto:geoengineering@googlegroups.com Sent: Friday, April 01, 2011 8:10 Subject: [geo] Wind and wave energies are not renewable after all Wind and wave energies are not renewable after all * 30 March 2011 by Mark Buchananhttp://www.newscientist.com/search?rbauthors=Mark+Buchanan * Magazine issue 2806http://www.newscientist.com/issue/2806. Subscribe and savehttp://www.newscientist.com/subscribe?promcode=nsarttop * For similar stories, visit the Energy and Fuelshttp://www.newscientist.com/topic/energy-fuels and Climate Changehttp://www.newscientist.com/topic/climate-change Topic Guides Editorial: The sun is our only truly renewable energy sourcehttp://www.newscientist.com/article/mg21028062.500-the-sun-is-our-only-truly-renewable-energy-source.html Build enough wind farms to replace fossil fuels and we could do as much damage to the climate as greenhouse global warming WITNESS a howling gale or an ocean storm, and it's hard to believe that humans could make a dent in the awesome natural forces that created them. Yet that is the provocative suggestion of one physicist who has done the sums. He concludes that it is a mistake to assume that energy sources like wind and waves are truly renewable. Build enough wind farms to replace fossil fuels, he
RE: [geo] Wind and wave energies are not renewable after all
Although I am member of Environmentalists For Nuclear (EFN) I suspect that it is our nuclear sponsors and Australian uranium mining who have concocted this concern of winds running out in the aftermath of Japan nuclear disaster in order to dismiss the renewables as serious alternative. In any case, it will take decades to build such capacity which should not be our immediate concern at all. Albert Date: Sat, 2 Apr 2011 20:17:40 + Subject: Re: Re: [geo] Wind and wave energies are not renewable after all From: voglerl...@gmail.com To: d.na...@gmail.com CC: agask...@nc.rr.com; andrew.lock...@gmail.com; geoengineering@googlegroups.com Hi All, Last year I read a short comment by Dr. Caldera on High Wind energy harvesting posted on Bill Gates website http://www.thegatesnotes.com/Conversations/What-About-Wind. Dr. Caldera stated if we were to meet future power demand by this source exclusively, we must intercept more than 1% of natural flows. I think when we get above a 1% change in a natural system, we need to be concerned about large scale unintended consequences.. And, now I see this report by Dr. Kleidon reporting concerns about Boundary Layer Winds and Wave Energy. I am somewhat disappointed that such exotic extrapolations are getting serious play on the issue of renewable energy. First, I believe Dr. Gaskill statement in this tread is the the clearest thinking on this issue of the use of these renewable energies. This planet is in fact solar powered and the solar energy that it receives is far more than we can use. Also, Boundary Layer winds are effected by the difference between the rotational speed of the planet and that of the total (fluid) mass of the atmosphere. High altitude winds also get impacted by this differential to a certain degree. Wave energy has not just the solar energy input, but, the added lunar diurnal gravitational influence. I am not an expert in any shape or form, but, I have twirled a coffee cup and watched how the boundary friction between the cup and fluid causes the fluid to move. And, I have stood by the shore and watched the force of a tide rise and fall and watched the wave production from that force. On a global scale, these basic physical forces are clearly significant enough to be considered into the equation. Looking beyond just the solar energy input/effect seems worth factoring into these types of calculations. We should not be looking to calculate any renewable energy option into the ground. We will need all of them (including High Wind) to power our civilization. Dr. Gaskill, when they wake you up, I'll cook breakfast! My reading of the article suggested that the authors of the study were principally claiming that wind has an impact on climate, so it is already being used. What wasn't clear from the article was what type of impact reducing the energy level of winds all over the globe through the prolific use of wind turbines might have. In a warming world, I understand we should expect stronger winds. On a simplistic generalized level that might not be relevant to local climate, slowing those stronger winds down might have an ameliorating effect on climate change. Hence the claim that The magnitude of the changes was comparable to the changes to the climate caused by doubling atmospheric concentrations of carbon dioxide might not be as bad as it is made to seem. As usually, I'm grasping at straws, but as a layman, that's what stood out for me. Nando On Sat, Apr 2, 2011 at 3:15 PM, Alvia Gaskill agask...@nc.rr.com wrote: Wind and wave energy are the result of the conversion of solar energy into kinetic energy, i.e. the motion of molecules. Once converted into kinetic energy it's a use it or lose it proposition. Extracting kinetic energy from the atmosphere or the ocean doesn't mean it won't be replaced by more energy from sunlight. Planting more trees will also intercept winds, albeit without the electricity generation. Who funded this research? The same people who want to prevent contact with alien civilizations? I note that the Royal Society was also a party to that one too. Note to Royal Society. When you actually find something under the bed I should be afraid of, wake me up. - Original Message - From: Andrew Lockley To: geoengineering Sent: Friday, April 01, 2011 8:10 Subject: [geo] Wind and wave energies are not renewable after all Wind and wave energies are not renewable after all 30 March 2011 by Mark Buchanan Magazine issue 2806. Subscribe and save For similar stories, visit the Energy and Fuels and Climate Change Topic Guides Editorial: The sun is our only truly renewable energy source Build enough wind farms to replace fossil fuels and we could do as much damage to the climate as greenhouse global warming WITNESS a howling gale
Re: [geo] Wind and wave energies are not renewable after all
Nando etal: 1. I take a different message from the original article by Axel Kleidon - still without a date to be published. The first material below is found at: http://www.newscientist.com/article/mg21028063.300-wind-and-wave-energies-are-not-renewable-after-all.html?page=1 2 A draft version of the Kleidon article, submitted about three weeks ago, and noted in the above article, is found at: http://arxiv.org/abs/1103.2014 3. The article's message for me is not about wind and waves. It is about the biosphere. Near the end (and I think that should be read first by many of us), Kleidon calls for a doubling of NPP. This is a call consistent with the CDR half of Geoengineering of main interest to you and I: Biochar. I believe his conclusion is only marginally consistent with other parts of CDR or Geoengineering. 4. I recommend all of his five diagrams - but especially the last several, which are new me. All are expressed in TW rather than GtC/yr terms - but the carbon implications are all spelled out. 5. I concur with your final comment below, as well - but believe we should look at Kleidon's analysis primarily from the aspect of our global biosphere. Ron - Original Message - From: Nando d.na...@gmail.com To: agask...@nc.rr.com Cc: andrew lockley andrew.lock...@gmail.com, geoengineering geoengineering@googlegroups.com Sent: Saturday, April 2, 2011 8:25:22 AM Subject: Re: [geo] Wind and wave energies are not renewable after all My reading of the article suggested that the authors of the study were principally claiming that wind has an impact on climate, so it is already being used. What wasn't clear from the article was what type of impact reducing the energy level of winds all over the globe through the prolific use of wind turbines might have. In a warming world, I understand we should expect stronger winds. On a simplistic generalized level that might not be relevant to local climate, slowing those stronger winds down might have an ameliorating effect on climate change. Hence the claim that The magnitude of the changes was comparable to the changes to the climate caused by doubling atmospheric concentrations of carbon dioxide might not be as bad as it is made to seem. As usually, I'm grasping at straws, but as a layman, that's what stood out for me. Nando On Sat, Apr 2, 2011 at 3:15 PM, Alvia Gaskill agask...@nc.rr.com wrote: Wind and wave energy are the result of the conversion of solar energy into kinetic energy, i.e. the motion of molecules. Once converted into kinetic energy it's a use it or lose it proposition. Extracting kinetic energy from the atmosphere or the ocean doesn't mean it won't be replaced by more energy from sunlight. Planting more trees will also intercept winds, albeit without the electricity generation. Who funded this research? The same people who want to prevent contact with alien civilizations? I note that the Royal Society was also a party to that one too. Note to Royal Society. When you actually find something under the bed I should be afraid of, wake me up. - Original Message - From: Andrew Lockley To: geoengineering Sent: Friday, April 01, 2011 8:10 Subject: [geo] Wind and wave energies are not renewable after all Wind and wave energies are not renewable after all • 30 March 2011 by Mark Buchanan • Magazine issue 2806 . Subscribe and save • For similar stories, visit the Energy and Fuels and Climate Change Topic Guides Editorial: The sun is our only truly renewable energy source Build enough wind farms to replace fossil fuels and we could do as much damage to the climate as greenhouse global warming WITNESS a howling gale or an ocean storm, and it's hard to believe that humans could make a dent in the awesome natural forces that created them. Yet that is the provocative suggestion of one physicist who has done the sums. He concludes that it is a mistake to assume that energy sources like wind and waves are truly renewable. Build enough wind farms to replace fossil fuels, he says, and we could seriously deplete the energy available in the atmosphere, with consequences as dire as severe climate change. Axel Kleidon of the Max Planck Institute for Biogeochemistry in Jena, Germany, says that efforts to satisfy a large proportion of our energy needs from the wind and waves will sap a significant proportion of the usable energy available from the sun. In effect, he says, we will be depleting green energy sources. His logic rests on the laws of thermodynamics, which point inescapably to the fact that only a fraction of the solar energy reaching Earth can be exploited to generate energy we can use. When energy from the sun reaches our atmosphere, some of it drives the winds and ocean currents, and evaporates water from the ground, raising it high into the air. Much of the rest is dissipated as heat, which we cannot harness. At present
Re: [geo] Wind and wave energies are not renewable after all
Wind and wave energy are the result of the conversion of solar energy into kinetic energy, i.e. the motion of molecules. Once converted into kinetic energy it's a use it or lose it proposition. Extracting kinetic energy from the atmosphere or the ocean doesn't mean it won't be replaced by more energy from sunlight. Planting more trees will also intercept winds, albeit without the electricity generation. Who funded this research? The same people who want to prevent contact with alien civilizations? I note that the Royal Society was also a party to that one too. Note to Royal Society. When you actually find something under the bed I should be afraid of, wake me up. - Original Message - From: Andrew Lockley To: geoengineering Sent: Friday, April 01, 2011 8:10 Subject: [geo] Wind and wave energies are not renewable after all Wind and wave energies are not renewable after all a.. 30 March 2011 by Mark Buchanan b.. Magazine issue 2806. Subscribe and save c.. For similar stories, visit the Energy and Fuels and Climate Change Topic Guides Editorial: The sun is our only truly renewable energy source Build enough wind farms to replace fossil fuels and we could do as much damage to the climate as greenhouse global warming WITNESS a howling gale or an ocean storm, and it's hard to believe that humans could make a dent in the awesome natural forces that created them. Yet that is the provocative suggestion of one physicist who has done the sums. He concludes that it is a mistake to assume that energy sources like wind and waves are truly renewable. Build enough wind farms to replace fossil fuels, he says, and we could seriously deplete the energy available in the atmosphere, with consequences as dire as severe climate change. Axel Kleidon of the Max Planck Institute for Biogeochemistry in Jena, Germany, says that efforts to satisfy a large proportion of our energy needs from the wind and waves will sap a significant proportion of the usable energy available from the sun. In effect, he says, we will be depleting green energy sources. His logic rests on the laws of thermodynamics, which point inescapably to the fact that only a fraction of the solar energy reaching Earth can be exploited to generate energy we can use. When energy from the sun reaches our atmosphere, some of it drives the winds and ocean currents, and evaporates water from the ground, raising it high into the air. Much of the rest is dissipated as heat, which we cannot harness. At present, humans use only about 1 part in 10,000 of the total energy that comes to Earth from the sun. But this ratio is misleading, Kleidon says. Instead, we should be looking at how much useful energy - called free energy in the parlance of thermodynamics - is available from the global system, and our impact on that. Humans currently use energy at the rate of 47 terawatts (TW) or trillions of watts, mostly by burning fossil fuels and harvesting farmed plants, Kleidon calculates in a paper to be published in Philosophical Transactions of the Royal Society. This corresponds to roughly 5 to 10 per cent of the free energy generated by the global system. It's hard to put a precise number on the fraction, he says, but we certainly use more of the free energy than [is used by] all geological processes. In other words, we have a greater effect on Earth's energy balance than all the earthquakes, volcanoes and tectonic plate movements put together. Radical as his thesis sounds, it is being taken seriously. Kleidon is at the forefront of a new wave of research, and the potential prize is huge, says Peter Cox, who studies climate system dynamics at the University of Exeter, UK. A theory of the thermodynamics of the Earth system could help us understand the constraints on humankind's sustainable use of resources. Indeed, Kleidon's calculations have profound implications for attempts to transform our energy supply. Of the 47 TW of energy that we use, about 17 TW comes from burning fossil fuels. So to replace this, we would need to build enough sustainable energy installations to generate at least 17 TW. And because no technology can ever be perfectly efficient, some of the free energy harnessed by wind and wave generators will be lost as heat. So by setting up wind and wave farms, we convert part of the sun's useful energy into unusable heat. Large-scale exploitation of wind energy will inevitably leave an imprint in the atmosphere, says Kleidon. Because we use so much free energy, and more every year, we'll deplete the reservoir of energy. He says this would probably show up first in wind farms themselves, where the gains expected from massive facilities just won't pan out as the energy of the Earth system is depleted. Using a model of global circulation, Kleidon found that the amount of energy which we can expect to harness from the wind is reduced by a
Re: [geo] Wind and wave energies are not renewable after all
Andrew Most of the energy in waves is at present dissipated as heat in water and sand at the beach. Data on the North Atlantic wave climate combined with the flow of the North Atlantic Drift suggest an increase in temperature on the beach by about 1/50 of a degree Celsius. If we built very efficient wave plant all the way along the coast we might reduce the temperature increase to 1/100 of a degree. But as we would be using the wave-generated electricity in homes and factories, most will end up warming the prevailing wind which is exchanging heat with the sea. The overall effect is a short diversion. Onshore wind turbines do produce a detectable increase in the evaporation rate of ground water leading to a lower river run-off and we should expect offshore wind turbines to increase evaporation from the sea which ought to restore run-off. It may be possible to design floating wind-driven machines which produce no electricity but put all the energy they extract into increasing the turbulence of the lower atmosphere over the sea. This should produce more rainfall down wind. Stephen Emeritus Professor of Engineering Design Institute for Energy Systems School of Engineering Mayfield Road University of Edinburgh EH9 3JL Scotland Tel +44 131 650 5704 Mobile 07795 203 195 www.see.ed.ac.uk/~shs On 02/04/2011 14:15, Alvia Gaskill wrote: Wind and wave energy are the result of the conversion of solar energy into kinetic energy, i.e. the motion of molecules. Once converted into kinetic energy it's a use it or lose it proposition. Extracting kinetic energy from the atmosphere or the ocean doesn't mean it won't be replaced by more energy from sunlight. Planting more trees will also intercept winds, albeit without the electricity generation. Who funded this research? The same people who want to prevent contact with alien civilizations? I note that the Royal Society was also a party to that one too. Note to Royal Society. When you actually find something under the bed I should be afraid of, wake me up. - Original Message - *From:* Andrew Lockley mailto:and...@andrewlockley.com *To:* geoengineering mailto:geoengineering@googlegroups.com *Sent:* Friday, April 01, 2011 8:10 *Subject:* [geo] Wind and wave energies are not renewable after all Wind and wave energies are not renewable after all * 30 March 2011 by *Mark Buchanan* http://www.newscientist.com/search?rbauthors=Mark+Buchanan * Magazine issue 2806 http://www.newscientist.com/issue/2806. *Subscribe and save* http://www.newscientist.com/subscribe?promcode=nsarttop * For similar stories, visit the *Energy and Fuels* http://www.newscientist.com/topic/energy-fuels and *Climate Change* http://www.newscientist.com/topic/climate-change Topic Guides *Editorial: *The sun is our only truly renewable energy source http://www.newscientist.com/article/mg21028062.500-the-sun-is-our-only-truly-renewable-energy-source.html /Build enough wind farms to replace fossil fuels and we could do as much damage to the climate as greenhouse global warming/ WITNESS a howling gale or an ocean storm, and it's hard to believe that humans could make a dent in the awesome natural forces that created them. Yet that is the provocative suggestion of one physicist who has done the sums. He concludes that it is a mistake to assume that energy sources like wind and waves are truly renewable. Build enough wind farms to replace fossil fuels, he says, and we could seriously deplete the energy available in the atmosphere, with consequences as dire as severe climate change. Axel Kleidon of the Max Planck Institute for Biogeochemistry in Jena, Germany, says that efforts to satisfy a large proportion of our energy needs from the wind and waves will sap a significant proportion of the usable energy available from the sun. In effect, he says, we will be depleting green energy sources. His logic rests on the laws of thermodynamics, which point inescapably to the fact that only a fraction of the solar energy reaching Earth can be exploited to generate energy we can use. When energy from the sun reaches our atmosphere, some of it drives the winds and ocean currents, and evaporates water from the ground, raising it high into the air. Much of the rest is dissipated as heat, which we cannot harness. At present, humans use only about 1 part in 10,000 of the total energy that comes to Earth from the sun. But this ratio is misleading, Kleidon says. Instead, we should be looking at how much useful energy - called free energy in the parlance of thermodynamics - is available from the global system, and our impact on that. Humans currently use energy at the rate of 47 terawatts (TW) or trillions of watts, mostly by burning
Re: [geo] Wind and wave energies are not renewable after all
My reading of the article suggested that the authors of the study were principally claiming that wind has an impact on climate, so it is already being used. What wasn't clear from the article was *what type* of impact reducing the energy level of winds all over the globe through the prolific use of wind turbines might have. In a warming world, I understand we should expect stronger winds. On a simplistic generalized level that might not be relevant to local climate, slowing those stronger winds down might have an ameliorating effect on climate change. Hence the claim that *The magnitude of the changes was comparable to the changes to the climate caused by doubling atmospheric concentrations of carbon dioxide* might not be as bad as it is made to seem. As usually, I'm grasping at straws, but as a layman, that's what stood out for me. Nando On Sat, Apr 2, 2011 at 3:15 PM, Alvia Gaskill agask...@nc.rr.com wrote: Wind and wave energy are the result of the conversion of solar energy into kinetic energy, i.e. the motion of molecules. Once converted into kinetic energy it's a use it or lose it proposition. Extracting kinetic energy from the atmosphere or the ocean doesn't mean it won't be replaced by more energy from sunlight. Planting more trees will also intercept winds, albeit without the electricity generation. Who funded this research? The same people who want to prevent contact with alien civilizations? I note that the Royal Society was also a party to that one too. Note to Royal Society. When you actually find something under the bed I should be afraid of, wake me up. - Original Message - *From:* Andrew Lockley and...@andrewlockley.com *To:* geoengineering geoengineering@googlegroups.com *Sent:* Friday, April 01, 2011 8:10 *Subject:* [geo] Wind and wave energies are not renewable after all Wind and wave energies are not renewable after all - 30 March 2011 by *Mark Buchanan*http://www.newscientist.com/search?rbauthors=Mark+Buchanan - Magazine issue 2806 http://www.newscientist.com/issue/2806. *Subscribe and save* http://www.newscientist.com/subscribe?promcode=nsarttop - For similar stories, visit the *Energy and Fuels*http://www.newscientist.com/topic/energy-fuels and *Climate Change*http://www.newscientist.com/topic/climate-change Topic Guides *Editorial: *The sun is our only truly renewable energy sourcehttp://www.newscientist.com/article/mg21028062.500-the-sun-is-our-only-truly-renewable-energy-source.html *Build enough wind farms to replace fossil fuels and we could do as much damage to the climate as greenhouse global warming* WITNESS a howling gale or an ocean storm, and it's hard to believe that humans could make a dent in the awesome natural forces that created them. Yet that is the provocative suggestion of one physicist who has done the sums. He concludes that it is a mistake to assume that energy sources like wind and waves are truly renewable. Build enough wind farms to replace fossil fuels, he says, and we could seriously deplete the energy available in the atmosphere, with consequences as dire as severe climate change. Axel Kleidon of the Max Planck Institute for Biogeochemistry in Jena, Germany, says that efforts to satisfy a large proportion of our energy needs from the wind and waves will sap a significant proportion of the usable energy available from the sun. In effect, he says, we will be depleting green energy sources. His logic rests on the laws of thermodynamics, which point inescapably to the fact that only a fraction of the solar energy reaching Earth can be exploited to generate energy we can use. When energy from the sun reaches our atmosphere, some of it drives the winds and ocean currents, and evaporates water from the ground, raising it high into the air. Much of the rest is dissipated as heat, which we cannot harness. At present, humans use only about 1 part in 10,000 of the total energy that comes to Earth from the sun. But this ratio is misleading, Kleidon says. Instead, we should be looking at how much useful energy - called free energy in the parlance of thermodynamics - is available from the global system, and our impact on that. Humans currently use energy at the rate of 47 terawatts (TW) or trillions of watts, mostly by burning fossil fuels and harvesting farmed plants, Kleidon calculates in a paper to be published in *Philosophical Transactions of the Royal Society* http://arxiv.org/abs/1103.2014. This corresponds to roughly 5 to 10 per cent of the free energy generated by the global system. It's hard to put a precise number on the fraction, he says, but we certainly use more of the free energy than [is used by] all geological processes. In other words, we have a greater effect on Earth's energy balance than all the earthquakes, volcanoes and tectonic plate movements put together. Radical as his thesis sounds, it is being taken seriously.
Re: [geo] Wind and wave energies are not renewable after all
Indeed, the authors do not appear to understand that a watt (joule/second) is a rate of energy conversion, not a unit of energy. If energy is converted slower here, there is more to convert there. A more interesting line of inquiry is the evaporation effect of slowing down surface wind (but not upper lever wind). Also re protecting crops from extreme wind damage etcthe significant effect of wind turbines is to thicken the boundary layer. John Duke - Original Message - From: Alvia Gaskill To: andrew.lock...@gmail.com ; geoengineering Sent: Saturday, April 02, 2011 9:15 AM Subject: Re: [geo] Wind and wave energies are not renewable after all Wind and wave energy are the result of the conversion of solar energy into kinetic energy, i.e. the motion of molecules. Once converted into kinetic energy it's a use it or lose it proposition. Extracting kinetic energy from the atmosphere or the ocean doesn't mean it won't be replaced by more energy from sunlight. Planting more trees will also intercept winds, albeit without the electricity generation. Who funded this research? The same people who want to prevent contact with alien civilizations? I note that the Royal Society was also a party to that one too. Note to Royal Society. When you actually find something under the bed I should be afraid of, wake me up. - Original Message - From: Andrew Lockley To: geoengineering Sent: Friday, April 01, 2011 8:10 Subject: [geo] Wind and wave energies are not renewable after all Wind and wave energies are not renewable after all a.. 30 March 2011 by Mark Buchanan b.. Magazine issue 2806. Subscribe and save c.. For similar stories, visit the Energy and Fuels and Climate Change Topic Guides Editorial: The sun is our only truly renewable energy source Build enough wind farms to replace fossil fuels and we could do as much damage to the climate as greenhouse global warming WITNESS a howling gale or an ocean storm, and it's hard to believe that humans could make a dent in the awesome natural forces that created them. Yet that is the provocative suggestion of one physicist who has done the sums. He concludes that it is a mistake to assume that energy sources like wind and waves are truly renewable. Build enough wind farms to replace fossil fuels, he says, and we could seriously deplete the energy available in the atmosphere, with consequences as dire as severe climate change. Axel Kleidon of the Max Planck Institute for Biogeochemistry in Jena, Germany, says that efforts to satisfy a large proportion of our energy needs from the wind and waves will sap a significant proportion of the usable energy available from the sun. In effect, he says, we will be depleting green energy sources. His logic rests on the laws of thermodynamics, which point inescapably to the fact that only a fraction of the solar energy reaching Earth can be exploited to generate energy we can use. When energy from the sun reaches our atmosphere, some of it drives the winds and ocean currents, and evaporates water from the ground, raising it high into the air. Much of the rest is dissipated as heat, which we cannot harness. At present, humans use only about 1 part in 10,000 of the total energy that comes to Earth from the sun. But this ratio is misleading, Kleidon says. Instead, we should be looking at how much useful energy - called free energy in the parlance of thermodynamics - is available from the global system, and our impact on that. Humans currently use energy at the rate of 47 terawatts (TW) or trillions of watts, mostly by burning fossil fuels and harvesting farmed plants, Kleidon calculates in a paper to be published in Philosophical Transactions of the Royal Society. This corresponds to roughly 5 to 10 per cent of the free energy generated by the global system. It's hard to put a precise number on the fraction, he says, but we certainly use more of the free energy than [is used by] all geological processes. In other words, we have a greater effect on Earth's energy balance than all the earthquakes, volcanoes and tectonic plate movements put together. Radical as his thesis sounds, it is being taken seriously. Kleidon is at the forefront of a new wave of research, and the potential prize is huge, says Peter Cox, who studies climate system dynamics at the University of Exeter, UK. A theory of the thermodynamics of the Earth system could help us understand the constraints on humankind's sustainable use of resources. Indeed, Kleidon's calculations have profound implications for attempts to transform our energy supply. Of the 47 TW of energy that we use, about 17 TW comes from burning fossil fuels. So to replace this, we would need to build enough sustainable energy installations to generate at least 17 TW. And because no technology can ever be perfectly efficient
