Most policy buffs suggest that governments should not pick winners in the renewable energy or any other field. Now there is a scientific reason for narrowing the choice – any energy source other than the sun and derivatives such as wind and waves ends up heating the planet. Most people would have thought that doesn’t matter, and to date it possibly hasn’t, but Eric Chaisson of the Harvard Smithsonian Center for Astrophysics says there is indeed an issue if we think in terms of centuries and energy for all of 9-10 billion people. He said it in a paper back in 2008 which you can download from here. It was picked up by the New Scientist in 2009 and again last week. Huggybunny drew our attention to it on this thread and perhaps the time for the idea has come.
The basic concern is that much of the energy we use ends up as heat, even as in heating the circuits of your computer or your fancy phone. Some turns into light or radio waves which are absorbed as heat by surfaces.
If we use nuclear power, for example, we are making heat out of uranium.
Currently humans use 16 terawatts (TW) of power at any moment, compared to 120,000 TW of solar power absorbed by the Earth at any given time. Energy consumption has been rising by about 2% pa for the last century. Chaisson’s original article based his calculations of (only) 9 billion people by 2100. Those in the OECD will increase their energy usage by 1% pa. The rest will increase theirs by 5% pa until parity is reached, and 1% pa from there. On this basis even if GHG emissions cease immediately the world will warm by 3C in 320 years, when he has us using 4800 TW. Given that we have already warmed by 0.8C since pre-industrial times and a further 0.5C or so is estimated to be in the pipeline, there’s little margin left even if you foolishly think we can warm by 2C with impunity.
There are other sources of power that won’t contribute to global warming. One is hydro power. A second, as John D pointed out on the previous thread, is tidal power, because the gravitational pull of the moon is there and is not going away. A third is bioenergy, which has other problems in some of its forms.
By the way, Chaisson calculates that the modern American uses 12.5 kilowatts of energy, whereas your average hunter gatherer used only 0.15.
There is other interesting material in the article about the effects of wind and solar on the climate. In California, for example, temperatures behind the wind towers were found to be higher at night and as much as 4C lower by day. We only produced 0.2TW from wind worldwide in 2011, so it is thought that we can go much further without affecting the weather generally but the ultimate limits of extractable energy from wind are much lower than solar. At most there is 68TW available, but one estimate indicates only 18TW may be extractable.
Huggy suggested a global grid of ultre-high voltage direct current (HVDC) transmission lines. Perhaps we could do one along each of the Tropic of Cancer and the Tropic of Capricorn, with lateral connections through the America’s, Europe/Africa and Asia/Australia.
Grossmann et al have been working on the concept of large solar regions connected by HVDC, for example here and here.
Here are a few more matters to consider.
In November last year Giles Parkinson at Climate Spectator spoke to former Ausra chief David Mills about a study Mills had done with former Ausra R&D specialist Wei Li Cheng and US Department of Energy analyst Phil Larochelle looking at whether solar and wind could supply enough electricity to run the US economy, including transport, using hourly data from 2006 and existing technology. They found that they could. Their concept assumed a HVDC network that replaced flatlining baseload power with “a system of flexible and inflexible energy mechanisms based around wind and solar and other sources.”
China, we are told, is installing more HVDC lines than any other country in the world.
You will be aware that there has been a lot of discussion about the prospect of a grid parity cross-over with solar. Back in June last year we looked at whether solar had come of age.
Parkinson’s update after Mills’ talk at the Solar 2011 conference last year made this comment on cost:
“People say we need baseload plans, but we don’t,” he says. Instead, grids can work perfectly well with a mixture of inflexible supply (wind that blows whenever it wants), and flexible supply (solar thermal with storage). Mills has yet to release the financial modelling for his scenario, but notes that wind is already cheaper than new-built coal in the US, and solar thermal with storage, and used as a peaking plant, will be competitive with peaking gas.
Mills was calculating only on large scale concentrated solar, which was his business, rather than on PV, whether in local distributed energy situations or larger arrays, as in this image from Germany:
German PV solar array
Also from the article:
The UNSW study, based on simulations of Australia’s energy needs in 2010, found that the entire supply could be met by a mix of solar thermal with storage, wind, solar PV, existing hydro and peaking gas plants running on biofuels. Only six hours of the year fail to meet the NEM’s reliability standard, all in evening peaks in the winter months.
That study involved Mark Diesendorf, and I worry about him.
A few weeks later Parkinson was at it again, suggesting that solar could be essentially free. If you include the cost a solar array in your mortgage and use the savings in electricity costs to pay off the mortgage you can pay off the mortgage early.
The International Energy Association (IEA) pointed out last year that in 90 minutes, enough sunlight strikes the earth to provide the entire planet’s energy needs for a year. They tested the limit of what they thought could be achieved with solar after 2035 if for whatever reason the world decided to move away from nuclear and carbon sequestration and storage (CCS) technology. I’ve taken a brief look at their vision in a separate post along with the notion of distributed generation. The ultimate would be to combine local generation and sharing with a word-wide network.
Clearly there is much for policy makers to think about and questions can be asked about Chaisson’s scenario. The IEA, for example, sees the world in 2060 as one that is four times richer, but through energy efficiency measures using only 50% more power.
Meanwhile Australia’s outlook for solar was characterised yesterday as not so sunny as we stumble towards establishing large-scale solar projects. The Clean Energy Council said a number of other countries have solar markets that are more mature than ours.
One is India, which is now generating cheap solar (8.78 rupees per kilowatt-hour compared with 17 rupees for diesel) in pursuing its “Solar Mission” to install 20,000 megawatts of solar power by 2022.
I didn’t follow the discussion around this topic – build up of waste heat and the implications for (in particular nuclear power) last time. Now I’ve had a look at the New Scientist article and it is very interesting. I haven’t yet read the paper itself but the argument is based on the assumption of increases in energy consumption going on into the future. Five percent per annum in the developing world until global parity is reached and 1 percent per annum in the already developed world in eternity. This is troubling. While history might suggest that this is a reasonable assumption, the realities of our climate situation show that it is nonsensical, a recipe for our self destruction.
A relatively familiar atmospheric carbon budgeting exercise that I’ve seen from several sources shows that if the globe is to have any chance of achieving a safe stable climate, and energy is to be distributed equitably, our per capita carbon budget must be about that enjoyed (or not) by Indians today. If we are to have a future at all the thinking goes, we in the west must massively reduce our greenhouse gas emissions Indians must hang in there where they are and the rest of the world can increase to India’s levels.
Of course readers of this blog are familiar with this argument but if anyone wants some background they might try http://www.climatecodered.org/2009/09/forget-about-2050-lets-talk-about-now.html. If my memory isn’t failing me completely I think David Spratt and Philip Sutton had a bit to say about this notion in their book Climate Code Red.
Having persuaded westerners to drop back to these levels (Ho Ho) for the sake of our shared future and the rest of the world to hold at the levels of India rather than surge on upwards in a consumerist frenzy (Ha Ha) the only improvements in material standard of living after that will depend on increasing energy efficiencies.
If the energy use assumptions underlying the paper in New Scientist play out in reality we will not have to worry about how to deal with the increased waste heat from all our gadgets. Long before this becomes a problem we will, in one way or another, be toast.
I have no quibbles with the narrowing of non fossil fuel based energy options the paper suggests/implies but I must say given the large line energy losses in the form of waste heat from power lines the logic of constructing global power grids to move solar electricity around as a remedy to an excess waste heat problem escapes me, but I’m not a scientist and there is probably much that I don’t understand about the physics of high voltage power lines or about the intricacies of the exchange out of which this suggestion emerged.
Localised energy and food and any other sort of production you can think of is surely central to our continued environmental viability. But then, as I say, I’m not a scientist.
There was a panel discussion about large scale solar on last night’s RN Drive with Matthew Wright and Tony Wood (Grattan Institute). The problems with the flagship programmes seem to have been anticipated by many. In summary, they agreed that pricing carbon and then providing feed-in tariffs for a period of fifteen or so years is necessary to drive the technology down the cost curve to a competitive level.
In Germany solar will come off feed-in tariffs by 2015, two years earlier than predicted. The other advantage according to Wright was that these tariffs open the energy market to other providers. They discussed the potential problems with reverse optioning which is the method the ACT will use to support large scale solar.
Frankly, I think this purported “heat problem” to be one of the more pointless discussions to be had. And is one that is only cropping up as a rather ridiculous anti-nuclear talking point and not because it has any practical significance.
Expansion of nuclear power by a factor of four would be enough to displace all coal burning for electricity generation. This would be around 1.5 TW of capacity which is trivial compared to the 5000 TW figure being floated as possibly triggering 3C rise in global temperature. It is even more trivial if one considers that it would be displacing coal, and (using LWRs) has only a little less thermal efficiency than coal.
But if we want to descend into real silliness, PV must also cause some change to the planetary energy balance because of a reduction of planetary albedo. What PV does is take EM radiation in the visible spectrum and turn it into electricity. Where does electricity end up – heat. Some of that light would have otherwise been reflected into space. The problem may be less than for thermal electricity, but it is still there and there are still limits. There will likely always be limits unless humans colonize other planets, which we all agree is rather a long way off in any meaningful sense.
What makes this discussion even more absurd is that the global energy system will be rebuilt multiple times before waste heat is likely to be any sort of consideration at a planetary scale. What we do now places no burden on future generations who might, hypothetically, face a waste heat issue in a civilization with vastly expanded energy use.
The same cannot be said for GHG emissions, whose residency in the atmosphere does not simply disappear with the replacement of energy infrastructure as it reaches the end of it’s service life. It is simply a distraction from, and indeed a trivialization of this core problem to start banging on waste heat.
#1 Doug Evans
Indeed so. In the abstract reaching a 5000 TW civilization might be possible but the practical difficulties would be immense and certainly insurmountable with current knowledge and capabilities. Humans might also like to ask themselves, well in advance of such circumstances, what sort of world they would like to inhabit.
The post, as published, said that the IEA saw the world in 2060 as using 50% of the power it uses now. The correct position is reflected in the other post:
I’ve changed the text accordingly.
I won’t answer the comments so far right now except to say, while it is highly questionable whether present trends towards increased per capita use of power will continue for a few centuries, the factor identified by Chaisson needs to be dealt with by good science, not guesswork or opinion. What it does seem to indicate, together with new information about the possibility of large-scale networking, is that an energy-rich future based on renewables is possible.
Good overview of the problem Brian, but can LP get over the ‘renewable’ energy chorus. We all know from the laws of thermodynamics that there is no such thing and beyond the headline this post clearly shows the way. I suggest we start using the term ‘transformable’ energy, but I know there are other possibilities.
Agree with you about Mark D.
#5 Pablo,
The term you might be looking for is Thermodynamic free energy Thermodynamic free energy
Of course the notion that governments shouldn’t pick winners is absurd. Build a coal-fired power station and you’re saying it’s better than all the alternatives. Build a tollway like Sydney’s Crosscity Tunnel, and you are saying that it is better than the alternatives. It’s just neocon nonsense.
This post immediately conflates two heat generation mechanisms
Hydro, tidal, etc power will contribute heat, as (quokka has pointed out), most energy ends up as heat (waste or deliberate).
other problems in some of its forms.
Its not just PV that changes the Earth’s albedo… what about agriculture, forestry (and deforestation), urbanisation, etc etc.
How GHG warming relates to human-induced thermal-energy from power generation vs. solar input, and then these two be used to linearly extrapolate future warming is anyone’s guess.
other problems in some of its formsMust have been dozing off when I wrote this. Of course we can go on growing solar and perhaps wind as long as we wish. – Oops. As I said not a scientist.
The isssue is that we must find a way to provide the energy needs of every person in the whole world with the minimum of adverse consequences.
This means free energy for domestic users in every place on the planet and paid for energy to drive industry and transport.
Fail in this task and we condemn millions of children to an early death from disease caused by the inhalation of wood and dung smoke. We condemn millions (mostly women) to the non productive task of fuel gathering.
We will dam rivers and destroy the natural infrastructure that maintains thousands of people, we will build more fossil fuelled power generation plants that lift the Co2 levels and spread toxic stuff all over the landscape. We will build nuclear power plants that can never provide free energy to any-one and that dump their toxic waste on native lands.
We will as well, condemn billions of people to a subsistence level existence and lock them out of the global economy.
We need to shift our focus from the piecemeal “solutions” that we faff about with at the moment and look at the really big picture.
To me the really big picture means that we find ways to derive all our energy by diverting some of the energy that streams through this planet every day and night , it comes with no outlay for fuel and will cost less to install than all the other piecemeal and polluting options. No new technology required, just the smart application of what we have now.
The most obvious solution is to build very large geographically dispersed solar power stations n aglobal basis and link them with HVDC into the existing and new distribution networks. We also improve the distribution efficiency by the provison of distributed energy storage (not required for base load so much as for distribution efficiency and reliability).
Huggy
“Hydro, tidal, etc power will contribute heat, as (quokka has pointed out), most energy ends up as heat (waste or deliberate).”
Can you explain this further, Duncan? I had a think about it the other night when Huggy and John D were discussing and I don’t see it.
They’re linear processes, yes? Energy in equals energy out. How can hydro or tidal contribute heat, or am I missing something?
“The UNSW study, based on simulations of Australia’s energy needs in 2010, found that the entire supply could be met by a mix of solar thermal with storage, wind, solar PV, existing hydro and peaking gas plants running on biofuels. Only six hours of the year fail to meet the NEM’s reliability standard, all in evening peaks in the winter months.”
Brian, I sure hope that you are being”colourful” in making this
“That study involved Mark Diesendorf, and I worry about him”
comment.
Diesendorf was a classmate of Mills, and for a long time was minimally supportive of Mill’s work. Mills suffered badly amoungst his peers from being a forward thinker and long time proponent of solar energy systems. Diesendorf, to his credit, has done the sums and exonerated Mills in his work. The fact is that Diesendorf is correct in his conclusions. Energy will indeed be essentially free for the average family in the near future.
There is a simple test to determine if this is true. Calculate the plan area of your abode. Divide by 2. Multiply by the highest efficiency solar panels available conventionally (hint .25) and multiply by the total number of clear solar day/hours available (hint for Sydney this is 275 times 7.5) in your area per year and divide by 365. Derate by 50% to allow for situational inefficiecy. For Sydney this will give you 35 kilowatt hours of energy per day average, or equal the average per household energy consumption, today. Then it comes down to the cost of reaping that harvest. Where that cost is incorporated into the mortgaged cost of the average new household it becomes an invisible cost. That is Diesendorf’s point, and I salute him for coming to that conclusion. Thankyou, Mark. You have balanced some less helpful publications of several years ago, and elevated the understanding to the future reality.
The fact is that the future reality is significantly better than that outlined even in Mark’s re-evaluation. And this is not a criticism, as I am sure that Mark is all too aware that to go beyond what he has declared would bring the evaluation into doubt as being “unbelieveable”.
To digress, a recent oil find in the North Sea’s Norwegian section has identified a massive find of some 19 biilion barrels of oil. This will take many years into the future to tap and bring to the market. The thing to keep in mind here is that this total resource amounts to just 3 months world oil supply, which currently stands at 87 billion barrels per year.
Perspective. Can you count on oil to supply the energy needs of your family for the next 40 years ( the likely term of a new mortgage for a young family)? The answer is NO.
On the day that bank forcloses on your home loan because you have been unable to pay your future fossil fuel energy bill, ………the sun almost certainly be shining.
Tidal does add to the total of waste heat.
Energy is extracted from the Earths rotation by increasing the drag effect of the tides over what it would have been if no generating capacity had been installed. Or to put it another way, installing generators increases the friction effect of tidal movement over what currently exists, at the expense of lengthening the day – by an infinitesimal but cumulative amount.
Nick,
Hydro, on the other hand, is arguably a form of solar power, and is a zero sum source. Solar energy, expressed as either either radiation or wind evaporates water, that water is deposited on highlands and then flows down hill. If that flow is trapped part war down and is then used as a pressure head to generate electricity, well, it has the same effect on total heat ultimately released as if no interruption to the flow had taken place.
As I said, zero sum – like wind or direct solar.
Nick, Chris,
I’m not talking about the heat/energy wasted during power generation, nor the comparison with power generation methods that release stored energy as heat (eg: fossil fuels etc). I’m talking about what that power gets used for.
It is zero sum at generation, but not at point of use.
All that ‘free’ hydro power goes into peoples’ computers, light bulbs, heaters and through lossy transmission equipment. All this stuff adds up to waste heat.
duncan,
Hydro is zero sum for the planets system as a whole. Energy is pumped from point A to point B, but in the end there is no heat generated which would not be generated anyway. A different distribution, true, but that’s all.
I think the largest generator of waste heat in the energy sector is climate change denialism. Get rid of that and we can have all the tidal power we want.
@18 Chris,
I’m sorry, but you’re wrong.
Consider the following thought experiment.
Let’s say bricks rain down from the sky, like water.
Now, we can let those bricks hit the ground with a large crash (potential energy converting to sound, heat and some deformation of the ground), or we can catch them 20ft up, and invent a brick-powered generator to power a few inefficient bar heaters.
Which scenario do you think creates more heat?
I think the most heat is probably created by people arguing about it.
Duncan,
There is exactly the same entropy / heat / disorder generated in each case. In fact, if there weren’t then the laws of thermodynamics would be wrong.
You are implying that in the second case there is more energy in the system than in the first. If so, where did that energy come from?
The bricks in each case have the same mass, the same gravitational potential energy and the same total momentum. Just because you drain some of that momentum off by catching them and using it to drive a turbine part way through the fall doesn’t affect the total energy of the system.
BilB, welcome back and thanks for the appreciation of Mark Diesendorf’s work. In view of that I think it better I don’t elaborate on what my concern was.
The only comment I’d like to make is on albedo. The reason I included the particular photo from Germany is that solar is not neutral in the environment. The NS article mentions albedo in relation to PV solar. Obviously if you put solar panels on a reflective white roof you capture radiation that would have been reflected. If we put solar on part of our unpainted corrugated iron roof and painted the rest white we’d probably be in front, but I wouldn’t know whether this has much significance.
Duncan @ 9 is right in that other things affect albedo. I understand that one of the reasons Hansen suggests 350ppm as a target rather than 280 is that the planet’s surface is more reflective now than it was pre-industrially.
Chris,
yes, but in the second case you’re more efficiently converting some of that energy to heat, rather than other forms
Albedo? I think that a quick glance out the window after take off on your next air travel adventure would confirm that there are very few, if any, white painted rooves anywhere where solar panels are deployed in volume. Furthermore I suspect that the amount of reflected light from the glass surface of fixed solar panels in the morning and afternoon might very well give solar panels a reflective edge in practice where panels are deployed over tiled and darker coloured rooves.
Having said that, if solar panels are to be deployed on mass to offset the consumption of fossil fuels, then it is a consideration. My expectation would be that the albedo effect of solar panels would be negligible in reality, but only a proper study would prove that.
Albedo,
I despair when I see all those grey/black rooftops in the McMansion developments. There sits on the same roof this massive air conditioner, der. In Saudi Arabia they build houses with black pebbles on a flat roof; again a massive air conditioner and no insulation on the walls.
The thing about the albedo of PV is that we can control it.
We can control the albedo of all our structures, it is easy to get any albedo we want, and yes Brian you are right about galvanised iron – it is shite so far as albedo is concerned.
“Waste” energy.
If we obtain our energy from:
Fossil fuels
or Nuclear
We add any energy to the planet
If we obtain our energy from
The sun
or Solar derivatives (Wind – Hydro)
or Gravitational forces (Tidal)
We do NOT add anergy to the planet, there can be no “waste” energy
However we may slightly perturb the energy balance by shifting the albedo – in the solar case. However we can control this to zero or to a small positive level to mitigate the existing CO2 forcing.
Energy Services
I want people to think in terms of the services that energy offers to us.
There is a huge payback for increasing energy use efficiency but it will not emerge unitil we demand that our refrigerators etc be made as efficient as possible. The new LED lighting systems are way more efficient than even the toxic CFLs and require about 1% of the material to make them and they will last 20 years.
Huggy
Thanks, Chris @ 15. That’s what I was missing.
Increased tidal friction causes the day to lengthen/distance of moon from earth to increase/potential energy increase…
But worth noting it’s physically impossible to ever harness enough tidal energy for it to cause significant warming.
Nick @ 27
Well, yes, but every little bit helps.
In fact, I think someone here has been reading too much Larry Niven; the Puppeteers had to move their planet away from its sun because their civilisation generated too much heat.
I have to say tho, any discussion of a civilisation which generated 5000 TW is so far beyond my imagination that any discussion of it would be pure fantasy. All I would say is that any society that wealthy could probably do whatever it damn well wants, like turn the entire planet into a park or wilderness reserve – although even at that consumption it still wouldn’t be even a Kardashev Type I civilisation……
24.Duncan
February 10, 2012 at 6:16 am | Permalink
Chris,
yes, but in the second case you’re more efficiently converting some of that energy to heat, rather than other forms
<<
Chris @ 28, I find it difficult to believe that we will continue to increase energy consumption in a linear fashion to the 5000 TW level.
As I said in the post, however, we really don’t have any margin to work with in warming the planet, so all factors need to be brought into calculation.
Brian @30
One factor that has so far attracted little attention but needs to be acknowledged is the surge in global warming that will accompany the wind back in greenhouse emissions as the aerosols that fossil fuel combustion causes reduce and disappear. James Hansen and NASA colleagues have produced a study that estimates this aerosol “dimming” at 1.2 degrees (plus or minus 0.2°), much higher than previously figured. According to the linked article:
If all aerosols were removed from the system, about half the 1.2° of lost cooling would appear very quickly as a pulse of warming, with the other half following over a few decades.
Doug, Thanks for the link to the David Spratt article. He and Philip Sutton in the Climate Code Red book addressed the problem of reducing CO2 levels and cleaning up aerosols a couple of years ago, but there hasn’t been enough attention to that issue.
Brian,
When we are talking about civilisational use 5000 TW of energy pa we need to acknowledge that any speculation is just an SF fantasy. We can’t know. And if we had that resource available to us what could we achieve?
Given that level of wealth and resource options open up. If you can’t see growth to that level then consider, how much energy would be required to build and maintain hundreds of megastructures such as O’Neill Habitats scattered around the solar system? Consider even near term systems, less than a generation away, such as massive smart dust networks and claytronics structures performing work and monitoring functions; trillions of components everywhere, each needing milli and microwatts of power. Each of these will add to the total energy budget, but the up side is that vast numbers of these things will be powered by energy scavenging. The power will be needed, utilised and counted in the total, but will add nothing to heat pollution.
Fossil fuels, nuclear and deep geothermal all add to the short term flow of energy at the earths surface. As a first approximation, power generation based on sources such as solar or interaction with objects in space have no effect on the net flow of energy to the earths surface. (There will be minor impacts such as changes to albedo mentioned above.)
Energy use will have some effect on radiation into space. For example, the light from cities will radiate into space more efficiently on cloudless days that some other forms of heat with different frequency distributions.
This does not mean that various clean energy sources will not have some climate effects. For example, energy extracted from ocean currents will slow down the distribution of energy between the poles and the equator.
There may be some time in the future when all the above really matters. In the mean time it all sounds like an excuse for procrastination.
John D @ 34 and Huggybunny @ 26
You are right about solar and those systems it pumps, hydro and wind, not resulting in excess heat pollution, but tidal / gravitational systems, I really do not understand the basis of your argument.
A watt extracted from these systems, from the energy contained in the earths rotation, results in exactly the same ultimate heat pollution as a watt extracted from fossil or nuclear.
So long as solar alone is used the planetary system remains in equilibrium, but as soon as any other source of energy, including extra added tidal drag, is used that equilibrium is upset.
Don’t forget, tidal energy is not extracted from existing drag, but from ADDED drag.
If you think I am missing something, please show me. Seriously, I am always willing to admit I am wrong.
Chris, in reading up a bit on tidal, there was a figure regularly thrown about that if we replace the entire planet’s current electrical generation with tidal energy (17TW, which I think would mean theoretically having to dam the entire planet’s oceans and rivers…like I said, physically impossible, as well as grand scale ecologically stupid), we double the Moon’s annual recession from Earth form 3.8cm to 7.6cm.
What does that mean? Well, to me it meant one year’s worth of additional waste heat equal to what natural tidal friction generates already. AFAIK, waste heat from natural tidal friction won’t be a problem for at least a few million years (or was it a few hundred million?), so at very worst I’m suspecting you can halve that amount to get your answer…
Nick,
regarding rotational energy being transformed to wast heat – something weird I read 5 min after reading your last comment:
http://omniclimate.wordpress.com/2012/02/11/venus-stranger-than-we-thought/
Just had a look at that link, Chris Harper @ 37. The man’s a lunatic.
Not according to the European Space Agency….
All he is doing is taking the data provided and working out the numbers.
http://www.esa.int/esaMI/Venus_Express/SEM0TLSXXXG_0.html
Chris Harper,
I think that here is general agreement that energy diverted from the solar flux be it directly or through derivatives such as wind or even hydro (this has some downsides) is entirely benign in its consequences.
Energy from other sources such as coal or nuclear can directly influence the planet by the addition of energy to the system, only relevant when we lift the global standard of living to the level enjoyed by our elites. Both sources inflict serious pollution and both have CO2 emissions (nuclear, a lot less apparently).
It strikes me that given that we have a proven HVDC transmission system that we may as well go direct to the large scale solar option.
Biggest advantage is that the fuel is free-unlike the coal and nuclear options.
Chris, you obviously didn’t follow the link I provided. His “proof” that AGW is logically impossible reminded me of the Time Cube, except that the lunacy was more tightly under control and there weren’t quite so many fonts and colours.
Chris @35: Because the earth rotates faster than the moon orbits there are tides in the sea that create flows of water as well as much smaller “tides” in the earth’s crust. The friction due to the flow of the water tides and the flexing of the crust ends up being converted to heat that has to be radiated into space to maintain the energy balance.
The interesting question is what effect extracting energy from the tides has on the transfer of energy between the earth and moon and the heat that needs to be radiated into space.
The simplest analogy I could think of for the tides was a see saw with a tank of water at each end with a pipe connecting the two tanks. This system will consume little energy because the weights at either end of the see saw don’t change. On the other hand, more energy will be required if water is flowing back and forth between the tanks via the pipe. Energy will be lost due to friction in the pipe and more energy is required at the start of each see saw because the lower tank will be heavier due to the flow between tanks.
If you stick a turbine in the pipe this will slow the flow of water and thus reduce the energy required to keep the see saw going. The interesting thing is that this suggests that using tidal power will actually have a cooling effect on the earth as well as slowing down the rate at which the earth’s rotation is reducing and the moon moving further away from the earth.
Huggy: It is a logical step too far to say that:
If nothing else we are more likely to make progress with strategies that don’t depend on great big projects and international agreement to work properly. It is one of the reasons I favour plug in hybrid cars as a better approach than pure EV at this stage.
DI(nr): aah, the prosecutor’s fallacy is a cracker isn’t it?
Shorter Omniclimate: The probability of this reality occurring is so small, so why should anything occur at all?
Last year a household brand innovator weighed into the clean energy innovation debate with it’s own commissioned economic research.
It appears they put money where their mouth is; last year, Google invested more than $915 million in clean energy projects–solar, wind and transmission.
HuggyBunny @ 40
Sorry, you missed the point…
I have no argument with you on the issue of solar pumped energy systems and heat pollution, it causes none. I have a problem with your position that tidal / gravitational also produce no heat pollution. It is my position that you are wrong, for reasons I explained in my comments re. tidal drag. I am interested in knowing why you claim otherwise.
Davis Irving @ 41
We were referring to the posting re. calculations of Venerian heat which would be a consequence of a hypothesised slowing of the rotation of Venus if the ESA measurements are correct. I don’t see what the mans position on AGW has to do with that.
That someone has an opinion on a controversial issue that I disagree with is no argument for me to reject everything that person has to say on every topic. If it were I would need to reject Newton (an alchemist), Einstein (a quantum physics denier) and Dawkins (a third rate theologian – I am atheist by the way, but I recognise mediocrity when I see it ). Given the genius of these men, in their core areas of expertise, such a position would be absurd.
Re the explanation of tides – yeah, sure. Sorry, I assumed that was a given.
Now, the see-saw you envisage needs an external energy source to operate at all, the tidal system does not. In installing the turbines you have increased the total frictional surface, yes, as the water flows it will be slowed down, but the same volume of water will still suffer the same displacement – simply requiring more energy to do so.
I am sorry, but your analogy falls down, the earth / moon / sun tidal system isn’t a see-saw. Having increased the frictional surface more energy will be extracted from the system, resulting in increased waste heat at the expense of rotational and revolutionary energy.
I can see your point, Chris Harper, but the idiocy makes it hard to take anything he says seriously.
Recall that Newton’s explanation of infinitesimals was deeply incoherent and involved a great deal of hand waving (and Leibnitz’ wasn’t much better) – we didn’t get a rigorous definition of limit until the 19th century.
Chris: I don’t believe his tidal energy calculation either – won’t the energy be dissipated over the entire mass of the planet, not just the surface?
DI @ 48,
I will take your word for that, I don’t know enough about the history of mathematics to hold an opinion. I had always thought that we still used the Leibnitz methodology, it being superior to Newtons ‘fluxions’, but I am happy to be wrong on this. I don’t have a dog in that fight.
Jess,
No, the energy is released at the point of friction. The bearings of the turbine, the turbulence of the water or atmosphere over the planetary surface at the point of contact, the rolling of sand grains against one another all generate frictional heat.
Heat is also generated by the distortion of the crust, this hypothetically being the basis of the internal heating of Io and Europa, but atmospheric and ocean tides have minimal effect on that heating. Their effects are maximised at the surface.
Chris: Heat is also generated by friction within the fluid as well as points of contact. In the sea saw analogy the force comes from the relative movement of the moon and earth.
If you put a turbine in the pipe it slows down the flow which results in reduced energy loss. The same happens if you place a turbine in the ocean, tidal river etc.
“A watt extracted from these systems, from the energy contained in the earths rotation, results in exactly the same ultimate heat pollution as a watt extracted from fossil or nuclear.”
Chris, you don’t there’s a difference between digging something out of the ground and cooking or fissioning the hell out of it to create steam to drive a turbine?
And harvesting some of the potential energy the tides have stored and will release anyway within the next 6-12 hours?
Of course there’s a tiny amount of friction induced during the process. So what?
By far, the greatest amount of heat pollution from coal and nuclear is caused by the process of extracting its millions/billions of years of stored energy. Not by directing it through a turbine once you’ve got it in a usable form which happens to be extremely hot.
In the case of tidal, it was useable to begin with…
(And since nobody’s pointed out my clanger @36, I’ll just…shh, what clanger)
“Chris, you don’t [think] there’s”
Chris: I was trying to be nice about it but his calculation is completely wrong.
In comparison to the energy released by dissipation in the crust of Venus, the dissipation due to viscous resistance between the atmosphere and planet surface is negligible.
(…and the overall heating effect of slowing the rotation of Venus will be very minor.)
An attempt at a maxim as food for thought…
Any extraction of energy that:
a) uses no more in 24 hours than was produced naturally in that same period
b) is ecologically sound
is worthwhile pursuing now and into the future.
[and for all practical intents and purposes, pablo, I think can quite rightly be called renewable]
I’m sure it can be improved on!