Energy return on investment

what is your take?

probably closer to true than not...

http://sunweber.blogspot.com/2011/12/machines-making-machines-making.html

There isn't really a 'take' on this. There are just numbers.


EROI is what you are looking for. Energy return on investment. How much energy goes in vs how much energy comes out. Wind turbines have a EROI of between 5 and 35 measured between 1977 and 2007.
Here is the link to the paper.
http://www.sciencedirect.com/science/article/pii/S096014810900055X

The newer, larger ones are towards the upper end on average.

It's also worth noting that Thomas Homer Dixons quote was taken out of context. Below are Thomas homer dixons actual words.

“
This text is selectively excerpted from a chapter written by David Hughes in Carbon Shift (2009), a book I co-edited. Here’s the full text (the words omitted on the circulated poster are enclosed in square brackets):

“[The concept of net energy must also be applied to renewable sources of energy, such as windmills and photovoltaics.] A two- megawatt windmill contains 260 tonnes of steel requiring 170 tonnes of coking coal and 300 tonnes of iron ore, all mined, transported and produced by hydrocarbons. [The question is: how long must a windmill generate energy before it creates more energy than it took to build it? At a good wind site, the energy payback day could be in three years or less; in a poor location, energy payback may be never. That is,] a windmill could spin until it falls apart and never generate as much energy as was invested in building it.”

It’s worth noting that it would be pointless to put wind turbines in poor locations, and it’s trivial, or meaningless, to say that a turbine would never pay back its embedded energy in a poor location.

So, 1) I didn’t write the text, 2) the text itself is selectively quoted, and 3) the argument it makes, taken in isolation, is meaningless. Three strikes.

Here is some more info on eroi (or eroei) it makes interesting reading.
https://en.wikipedia.org/wiki/Energy_returned_on_energy_invested#Criticism_of_EROEI

So much of the "revolutionary green tech" you see these days on hyped blog articles doens't look at energy and raw materials invested vs. energy returned or saved seriously. The more I look at it, the more it seems to me that small-scale decentralized low-tech is more sustainable, but I might be wrong.

As a side note, I wonder how much raw materials and fossil fuel it takes to build a Tesla car..

Thanks a lot everybody!

Alex Apfelbaum wrote:So much of the "revolutionary green tech" you see these days on hyped blog articles doens't look at energy and raw materials invested vs. energy returned or saved seriously. The more I look at it, the more it seems to me that small-scale decentralized low-tech is more sustainable, but I might be wrong.

As a side note, I wonder how much raw materials and fossil fuel it takes to build a Tesla car..

Alex, i would say i'm low tech too. Even scrapyard low tech. My plan, for the near future. Make a 60kw gen set for my sawmill. And run it tri fuel. Diesel at startup. Switching to WWO when i cab get some. And also, make a woodgas retort, to run the diesel engine on a mixture of diesel or oil, and woodgas. Like the aussies use butane in their road diesels.

I think we need big centralized projects. Like ITER. No way this can be done any other way. I love cars, and i agree that some hybrid ones are nice. I bloody hate the prius tho! And it's nowhere near as green as it claims to be! Make fosil or nuclear electricity, to power a car. Ney nice imho. I would say, i'm a strong advocate of direct hybrids. Where the batteries are there just to give thge acceleration needed, when not going downhill or iddling. Most of the vehicules don't need more than a 20kw engine on average. The EROI on making bigger engines is not that good. Small engine/generator, big electric motors and a battery bank or supercapacitors, and the vehicule becomes fun and a smidge more ecological.

But i'm a strong believer of microhydro and the likes.

For example, where i live, we all need presure reducers on our water lines. The good idea would be to insert a water turbine in line with the water supply, which would reduce the presure, and produce electricity. It would even produce it when people are at home, and the most needed. Or may be i'm just fooling myself! Mind you, here, we have no shortage of water!

An interesting read with some more data : How Much CO2 Gets Emitted to Build a Wind Turbine?

A coal fired power station requires an initial investment of raw materials when it's constructed, just like a windmill.

The difference then is that a power station continues to require inputs of fossil fuels in order to produce power, while a windmill just requires wind.

But you don't just let a windmill run and run until it falls apart. You maintain it. You replace things that wear out. One day the motor will need to be replaced altogether. You won't destroy the entire mast, foundation, etc, you'll simply replace the motor. This will cost nowhere near as much as initial construction.

And the new windmill motor won't cost as much as the old one, as you learned how to make them better. And you learned how to make them produce more power with less wind. You can't make the second, better windmill before the first one. That's not how discovery and innovation works.

One day, some engineer will be working on the very latest generation of windmill, and will have his eureka moment. We were doing it wrong all along, THIS is how we were meant to be doing it! But he couldn't have had that eureka moment without us having first made all those expensive and inefficient prototypes.

Each new generation of coal fired power station is more efficient than the last one. Why isn't alternative energy allowed the same process?

I would say it is true


http://www.dailymail.co.uk/home/moslive/article-1350811/In-China-true-cost-Britains-clean-green-wind-power-experiment-Pollution-disastrous-scale.html

And more

http://www.businessinsider.com/photos-of-chinese-rare-earth-mining-2013-4?op=1&IR=T

And still more

http://www.independent.co.uk/environment/green-living/are-wind-farms-a-health-risk-us-scientist-identifies-wind-turbine-syndrome-1766254.html

http://www.zdnet.com/article/do-wind-farms-have-a-negative-effect-on-the-environment/

http://www.theguardian.com/environment/2013/may/14/us-windfarms-eagle-deaths

Alex, with all due respect, this is extremely tiresome, and time consuming, to do.

"Continued fast expansion in offshore and onshore wind is good news for carbon emissions and can be accommodated without major problems by the grid. Data, not assertions, are what must win the argument over wind – and the data is very clear."

http://www.theguardian.com/environment/blog/2012/sep/26/myth-wind-turbines-carbon-emissions

and while the guardian cannot be relied upon as a single source by any means, and is not above pushing it's own agenda pretty ferociously when it wishes, it does often run some very good science pieces such as this.
The website you are linking to is written and moderated by an anonymous person who wishes to "destroy" the wind industry and makes claims that are demonstrably untrue. It's not a reliable source and nether are its "experts"

Angus Taylor has referred to anthropogenic climate change as "the new climate religion" telling Parliament that "religious belief is based on faith not facts. The new climate religion, recruiting disciples every day, has little basis on fact and everything to do with blind faith."

Alan Moran, who has been one of the most vociferous and long-standing opponents of renewable energy and controls on greenhouse gas emissions in this country[Australia], has apparently been sacked from the Institute of Public Affairs – a right-wing think tank.

The chief of the IPA, John Roskam told The Australian newspaper that Moran had left the IPA due to concerns about his “social media activity”.

The Australian noted that in recent weeks Alan Moran’s tweet, “Is there ever anything but evil coming from Islam?’’, had incited considerable outrage in the community. In addition, Moran controversially suggested that deputy Labor leader Tanya Plibersek was using rape allegations to destabilise Bill Shorten’s leadership.

Peter Quinn is a lawyer.

More about Stephen Cooper here, http://www.abc.net.au/mediawatch/transcripts/s4189864.htm and the over-stated claims made in the media

All in all, not credible at all.

Can I just remind everyone to keep to the topic. If anyone wants to discuss climate change, then it has to be within the cider press, not the main forums.

Satamax Antone wrote:i'm low tech too. Even scrapyard low tech [...] I think we need big centralized projects. Like ITER.

Low-tech as an individual, and (extremely) high-tech regarding society as a whole then, if I read you correctly ?

Satamax Antone wrote:The good idea would be to insert a water turbine in line with the water supply, which would reduce the presure, and produce electricity.

I had to reduce the water pressure at my place too and was thinking the same, micro-hydro where water is avalable is very exciting !

Rus Williams wrote:Alex, with all due respect [...] The website you are linking to is [...] not a reliable source

Sorry, I realized after posting what this website was. It certainly needs some further digging and I'm unable to verify the sources the article bases the facts it quotes on, but then this goes for any article. Even the "official experts" are very far from being unbiased, as has been proven many times.

For me personally, large-scale centralized renewable is still a long term unsustainable techno utopia. These things are the opposite of appropriate tech, they are non-democratic closed technologies that are impossible to operate, maintain and repair by the average community. They depend on large corporations and the power of military states so secure the influx of raw materials and energy necessary for their manufacturing. It's not the future I want to see, but hey that's juste me I like the low-tech utopia better

I think the question needs to be not so much "are wind turbines sustainable forever" but "are wind turbines sustainable for the time it will take to transition our entire society from its intensive energy use to a much lower energy use".

We can spend resources on building new fossil fuel power plants, or we can spend them on building wind turbines and solar panels. At some point, the economics will guide a transition without government forcing.

Russ Williams. Your first post is the best "slam dunk" answer that I've read this year. Partial quotes can be used to make points completely counter to what the originator intended.

Rus Williams wrote:There isn't really a 'take' on this. There are just numbers.



It's also worth noting that Thomas Homer Dixons quote was taken out of context. Below are Thomas homer dixons actual words.

“
This text is selectively excerpted from a chapter written by David Hughes in Carbon Shift (2009), a book I co-edited. Here’s the full text (the words omitted on the circulated poster are enclosed in square brackets):

“[The concept of net energy must also be applied to renewable sources of energy, such as windmills and photovoltaics.] A two- megawatt windmill contains 260 tonnes of steel requiring 170 tonnes of coking coal and 300 tonnes of iron ore, all mined, transported and produced by hydrocarbons. [The question is: how long must a windmill generate energy before it creates more energy than it took to build it? At a good wind site, the energy payback day could be in three years or less; in a poor location, energy payback may be never. That is,] a windmill could spin until it falls apart and never generate as much energy as was invested in building it.”

It’s worth noting that it would be pointless to put wind turbines in poor locations, and it’s trivial, or meaningless, to say that a turbine would never pay back its embedded energy in a poor location.

So, 1) I didn’t write the text, 2) the text itself is selectively quoted, and 3) the argument it makes, taken in isolation, is meaningless. Three strikes.

Thank you for your research. To me, it is just sooo dishonest to appear to quote an expert's words, yet edit the statement to make it say what you want it to say. Which University did such a person get a diploma? I'm so fed up with such dishonest drivel that I reject such criticism outright: Once you see that they are dissembling, twisting words, quoting selectively, there just is not reason to even consider any statement made by them... ever. Again, thank you for exposing the "artful smear" against this technology.

Alex Apfelbaum wrote: The more I look at it, the more it seems to me that small-scale decentralized low-tech is more sustainable, but I might be wrong.

Alex, we are probably moving to Castellon shortly and are looking at buying a small wind generator. Our needs are very simple, mostly to run a fridge freezer and some LED lights and run our laptops. Do you have any advice, thanks. Are you up in Catalunia?

In Texas trucks are hauling winmill parts West all day everyday. Wind turbines further than the eye can see in every direction West of sweet water. Driving by at 85 mph, half and hour later your start to realize how many have been put up.

I looked ink building a breezy 7kw generator and there is only one company that you can sell the power to. They are tax payer funded and buy the electricity for what normal power sells for. So, the turbines and the sell of this power is coming out of the pockets of tax payers. Profitable without this input? Im not sure. As many as 15% are broken at any time and service cost 30,000 or more.

I think it's kinkd of good for enery security, and the air we breathe, but...

Considering Texas is an enormous wasteful energy hog, this is pretty impressive: http://blogs.scientificamerican.com/plugged-in/texas-sets-new-all-time-wind-energy-record/

Just think what we could do if we conserved for a change!

Not sure how bad the problem actually is, but I've read that wind farms chew up quite a few birds.

Depending on where they are located, they can be bad for birds, and bats.

http://savetheeaglesinternational.org/new/us-windfarms-kill-10-20-times-more-than-previously-thought.html

http://news.nationalgeographic.com/energy/2015/09/150902-wind-industry-feathering-to-help-protect-bats/

Alternative energy is often called upon to live up to higher standards than conventional energy. For instance, alternatives are always required to "pay for themselves" whereas fossil fuels and nukes are not. Similarly, wind and solar are criticized for wildlife deaths more perhaps than fossil fuels and nukes are.

http://thinkprogress.org/climate/2014/08/25/3475348/bird-death-comparison-chart/

Victor Johanson wrote:Not sure how bad the problem actually is, but I've read that wind farms chew up quite a few birds.

Yes wind turbines kill birds but orders of magnitude less than say automobiles, cats



or building windows



The picture won't load, there's a nice graph here
https://en.wikipedia.org/wiki/Environmental_impact_of_wind_power#/media/File:Bird_mortality.svg

This doesn't make it right but turbines really not a major bird killer. There is a question about types of birds which are getting killed but still, all the evidence seems to point at it not being a major problem, especially people a getting better at understanding the impact at a local level, and iirc there have been wind farm applications turned down due to the adverse effect that particular wind farm would have on the local bird population.

In summary, it's a problem, but not a big one.

It is true that cats are bird killers, they usually kill small birds, same for windows. Turbines kill large birds, mostly protected, endangered species like the American golden eagle for example. As more and more turbines will be built, more and more large birds will disappear.

Olga Booker wrote: As more and more turbines will be built, more and more large birds will disappear.

All the more reason to promote energy conservation, so fewer turbines need be built, and increase bird habitat, so more birds have a place to live.

Olga Booker wrote:As more and more turbines will be built, more and more large birds will disappear.

Seriously? 234,000 vs 2,400,000,000 and that's just cats! Bird mortality is a concern, and good thinking is addressing this problem. I would not be surprised to see new ways of preventing bird deaths from wind turbines (along with keeping them out of flyways, which is already being done) invented and put into place shortly. In the meantime, put bells on your cats and grow beans in front of your windows!

stuart vencill wrote: Rus, may I inquire what part of the omitted text (in the poster under discussion) alters the POINT of the poster? ... Wind may provide a small off-grid/ rural / suburbanite some electrical juice when the breezes blow, it will NEVER make up for the energy it took to build it; the hot air from green radicals will not change physics or mathematics... Finally, your other comment which dismissed the politicians who are against wind power because of their non-PC views and "right wing" political stance is neither germane nor appropriate to whether or not large-scale wind energy will ever pay back the energy it took to build those hideous tax-payer funded energy sinks.

Stuart, I'm afraid you did miss the central point of Rus' posts, that the energy return (gain) on the amount of energy invested in production and installation of wind turbines is on the order of 5 to 35 times, generally increasing over the last 30 years. Rus also did not call into question others' criticisms of the returns from wind turbines based on their politics, but rather the factual basis of their arguments. Rus' point is that wind turbines do "make up for the energy it took to build [them]." And he brought facts to support that assertion. I'm afraid I don't find any facts in your post to support your assertions.

Olga Booker wrote:Turbines kill large birds, mostly protected, endangered species like the American golden eagle for example. As more and more turbines will be built, more and more large birds will disappear.

I wonder.

When cane toads were first introduced to Australia and began poisoning the native snake and lizard populations, predictions were made of a catastrophic collapse in local ecosystems.

A few decades later, nothing had changed. The snakes and lizards were still there. But their heads and mouths were smaller. The poisonous toads had selected for predators that had heads too small to eat the toads and die. Magpies and ravens had learned to flip the toads over and avoid the poisonous glands on the toads' backs in order to eat their innards.

It will be interesting to see if in a few decades there will be the same numbers of large birds, but ones that seem to mysteriously avoid wind farms.

stuart vencill wrote: Rus, may I inquire what part of the omitted text (in the poster under discussion) alters the POINT of the poster?

Stuart, I'm afraid I agree with Jerry here.

Rus Williams wrote:...Below are Thomas homer dixons actual words.

“
This text is selectively excerpted from a chapter written by David Hughes in Carbon Shift (2009), a book I co-edited. Here’s the full text (the words omitted on the circulated poster are enclosed in square brackets):

“[The concept of net energy must also be applied to renewable sources of energy, such as windmills and photovoltaics.] A two- megawatt windmill contains 260 tonnes of steel requiring 170 tonnes of coking coal and 300 tonnes of iron ore, all mined, transported and produced by hydrocarbons. [The question is: how long must a windmill generate energy before it creates more energy than it took to build it? At a good wind site, the energy payback day could be in three years or less; in a poor location, energy payback may be never. That is,] a windmill could spin until it falls apart and never generate as much energy as was invested in building it.”

It’s worth noting that it would be pointless to put wind turbines in poor locations, and it’s trivial, or meaningless, to say that a turbine would never pay back its embedded energy in a poor location.

The poster is clearly trying to make the point, "Wind power is stupid because it consumes more power than it produces."
This is a serious charge against a young industry, and the maker of the poster clearly feels the need to back up this claim with numbers.

When the best quote he can find, with impressive sounding numbers, is from a fellow who says "At a good wind site, the energy payback day could be in three years or less ..."

and he/she leaves out the expert's conclusions to make their own point instead,
to me that reads like a deliberate attempt to mislead, if not outright lie.

There is a difference between trying to make a point that you believe to be true, and trying to make a point with reckless disregard for truth or ethics.

I also feel that mis-quoting someone with such deliberateness is disrespectful to the expert being quoted.

If you want to impress people with facts, at least find the numbers yourself, or quote an "expert" who agrees with your basic point. If the only experts who agreed with you do not sound impressive enough to feature on your poster, and you feel that Thomas Homer Dixon is the most believable source, then why not believe (or at least consider) his conclusions about payback time on energy invested?

No technology earns its keep sitting in stillness in a basement, or becalmed in a quiet forest.

I have made the following statement, to discourage people from building an unnecessary or inconvenient artifact in the wrong place:
"A rocket mass heater that is never used will never pay me back."

If someone misquoted me by saying "A rocket mass heater... will never pay me back," I would be pretty ticked off.

Given how obvious it would be to anyone who has read the full quote, that the person who abridged it must have read the full quote as well, I would be inclined to mistrust the person who created it, and any organization that sponsored it.
It is not worth my time to try to figure out what the "truth" is behind their carefully-butchered quotes.

If you believe that the poster's creator makes a legitimate point, AND you disagree with Dixon's conclusions which were deliberately omitted, then the most useful contribution would be:
1) As an engineer, go run and show the numbers that support a different conclusion, or
2) Find an equally informed quote from someone who has.

I think it's only a matter of time before we're using wind and solar power to produce (and maybe even transport, someday) more windmills and solar panels.

Ok let's say that all our wind turbines are in the perfect spot and return the energy invested in a couple of years. Sounds dandy right ?

But still, the raw materials needed for their manufacturing are extracted in distant (often un-democratic) countries using extremely polluting methods (see here and here), especialy the rare earths (take a look at Baotou in inner Mongolia). The global rush to open new rare earth mines all over the world is inevitably going to come with all the side effects of the extractive industry. Then of course there's shipping, which is done by ocean-going ships and trucks, also very polluting and using vast amounts of fossil fuels.

How are these issues factored in when we say that windmills are "green" ?

Alex Apfelbaum wrote:
How are these issues factored in when we say that windmills are "green" ?

I consider windmills "less bad" than coal and nukes. I don't consider large wind energy farms "green," personally. I favor conservation and small-scale, distributed energy production. But I don't know for certain if that is "green" either, because of the need for mining in order to produce the equipment. I think a truly green way of life would look very different from what most of us are used to.

Alex Apfelbaum wrote:Ok let's say that all our wind turbines are in the perfect spot and return the energy invested in a couple of years. Sounds dandy right ?

But still, the raw materials needed for their manufacturing are extracted in distant (often un-democratic) countries using extremely polluting methods (see here and here), especialy the rare earths (take a look at Baotou in inner Mongolia). The global rush to open new rare earth mines all over the world is inevitably going to come with all the side effects of the extractive industry. Then of course there's shipping, which is done by ocean-going ships and trucks, also very polluting and using vast amounts of fossil fuels.

How are these issues factored in when we say that windmills are "green" ?

Alex, the point is not that saying these things makes windmills more or less green. Green is a totally subjective term that has little merit in a technical conversation.

Now comparisons are another thing. (a good thing)

All of the things you say are needed to build generating windmill are needed to build any kind of generator. Whether it's coal, diesel, wind, nuclear, or solar, rare materials will be needed. This is a fact that no electricity generator can hide from (even the turbines in hydrodams are built with modern methods, which include computer controls and high tech sensors)

If you want to do a solid comparison I'd model it something like this:
Development costs (resource cost more than monetary cost) for getting each system to the point where it can be turned on.
Cost/Unit of energy or Cost/year (good chance there isn't a single cost associated to a unit of energy or time but instead a whole range of costs based on conditions, but using all three of min/avg/max numbers paints a pretty picture).
Pollution/waste controls/year (like removing ash, soot, chemicals from stockpiles or waterways)
Lifetime costs (resource inputs/lifetime, pollution/lifetime, human hours input/lifetime)

As you can see there are many ways to look at and compare technologies. A single comparison of numbers without context is not enough to effectively determine anything at all.

And most of all of the things we use electricity for are filled with rare earth metals sourced unethically. This computer I am typing on for example.

Dan alan wrote:In Texas trucks are hauling winmill parts West all day everyday. They are tax payer funded and buy the electricity for what normal power sells for. So, the turbines and the sell of this power is coming out of the pockets of tax payers. Profitable without this input? Im not sure.

I think it's kinkd of good for enery security, and the air we breathe, but...

When we try to account for the costs of a technology, we have to account for *all* the costs of *both* technologies you are comparing. Yep, I'm sure eolian fields are expensive to build and to maintain but you do realize that many multi-national oil companies are taxpayer funded and subsidized too, right? The fact that wind farms sell their electricity at the same price as fossil fuel generated electricity is understandable: Supply and demand. As you mentioned, there are repairs to be made, just like there are repairs to be made on oil pipelines... Well, if they WERE making repairs on pipelines, there would be repair costs. (Instead, they just let the pipeline rot in the ground and cross their fingers the leak won't happen on their watch.)
If you add up the cost of wars for oils [in the trillions and counting], deaths of our young people, long term health problems (amputations, mental problems) and loss to their families, occasional pollution due to spills https://en.wikipedia.org/wiki/List_of_oil_spills maybe windmill farms are not so bad, me think. IMHO, they look pretty ugly, so tall and awkward on the plains of Illinois, but still, they look better than an oil spill.
If Central Wisconsin was good for wind power, I'd love to get some land to put windmills on and get a little income. (But our location is only mediocre) As is, I wish our farmers made some money with wind turbines instead of Confined Animal Feeding Operations. Enbridge line 61 is a Wisconsin pipeline carrying tarsands from Superior to the south east of the State. It has had already quite a few leaks and passes less than 5 miles away from me. It passes through several cranberry marshes and under the Wisconsin River before going right through our sandy aquifer. What could possibly go wrong?[Send a little prayer our way]

kyle saunders wrote:Alex, the point is not that saying these things makes windmills more or less green. Green is a totally subjective term that has little merit in a technical conversation.

I agree with everything you wrote Kyle. What I'm trying to say (going back to the original discussion in this thread) is that EROI is one thing, but it's important to look at the larger picture of our high-tech green solutions. They may be energetically efficient, but at what ecological and societal costs? Those externalities (like corporations like to call them) have an enormous impact on the planet and the people. Can we calculate them with precision? No, but that doesn't make them less important.

kyle saunders wrote:And most of all of the things we use electricity for are filled with rare earth metals sourced unethically. This computer I am typing on for example.

Yes pretty much anything containing modern electronics. That's why it is so important for us people of the "delveloped world" (sic) to dramatically scale down our lifestyles to more sustainable levels. A whole planet driving Teslas charged with solar and wind would probably be a complete ecological catastrophe.

A whole planet driving Teslas charged with solar and wind would probably be a complete ecological catastrophe.

(full disclosure, I am ignorant to the answers of my next questions, and actually wondering, hoping someone can chime in)

I wonder how much difference it would be really. I don't know how different digging up vast mountains for coal, oil and iron will be different than digging up mountains for these rarer materials? Obviously there will be less return per dig, but how much more can the impact be per dig?

I know that refinery processes are different for each material, such that oil is split up into many different products, metals are melted out of their ore. But what is different for these rarer materials that is not currently being done to traditional materials?

What materials are being used to create windmills that don't exist in fossil energy plants?

I really don't know what new environmental factors we'll face by switching energy materials.

One thing I can think of is that there is a good chance that since these materials were not commonly mined for in the past is that we'll need new mines in more virgin lands to find them. But this is the same for all mined materials, whether it's a new material being sought after or an old mine where the old material ran out.

Hmm. Open to being schooled!

@Alex A.: "A whole planet driving Teslas charged with solar and wind would probably be a complete ecological catastrophe."

Again, context is everything. Even in the early days of electricity, before rural electrification, there were small windchargers for batteries on farms, not to mention the value of small windmills in pumping water and other chores. In the right locations and at the right scale....and given the population density present.....wind seems to be a valuable player in the electrical energy equation. And even pushing more of what Kyle noted, the word "windmill" is as variable and context dependent as is the word "green". Is a 10 megawatt turbine more "resource unfriendly" than 1000 turbines of 1 kW rating? Although I don't know the answer to that question, aesthetically I dislike the mega windfarms going up around us and would prefer to see 1000 small turbines distributed around the region at individual farm sites. [Just saw your most recent entry kyle and don't have the answers to that, but I suspect the answer will be pretty complicated and much of the information very biased.] But more to the point: The fact that we all know you you mean when you say "A whole planet....." is indicative of how the human mind extrapolates and uses metaphor. What you really mean is "7+ billion people....", i.e., the human component of "the planet". This can of course change quite suddenly given even historically documented impacts globally, not to mention some we may not have considered or experienced. Suddenly energy consumption and ecological impact per dwelling can be looked at differently. Irrespective of that particular contexual factor, small wind, like small solar, like small cars, like small tractors, like small RMHs (I mean, why don't we as a society just get behind really HUGE....I mean HUGE!!.... RMHs for creating steam to replace coal and nuke fired plants! The combustion bell would dwarf that of a nuke cooling tower!... ....I'm kidding)...*along* with reduced consumption (either in the form of a reduction in energy unit per dwelling or in the form of a reduction in the raw number of dwellings) seems reasonable. Diversity of ideas, diversity of food and energy resources, and diversity of implementation seem to be most robust. Since we are in a part of the US that benefits from winds, I would still consider electricity from wind, in combination with solar, at our location along with reduced consumption, the latter resulting from reducing "needs" and increasing energy efficiency in both active and passive forms.

kyle saunders wrote:I don't know how different digging up vast mountains for coal, oil and iron will be different than digging up mountains for these rarer materials? [...] what is different for these rarer materials that is not currently being done to traditional materials?

There are problems with all types of mining, but rare earths business is really nasty.

Here's from the article I linked a few posts ago :

Although rare earths are abundant in the earth's crust, they are difficult to find in commercially viable concentrations. Extracting individual elements from the host mineral's chemistry is a complex and energy-intensive process, involving strong acids and other hazardous chemicals. Radioactive materials such as uranium and thorium are often found alongside rare earth elements, and these can end up in the "tailings" – a toxic stew of waste products from the refinement process.

From the second article :

Processing rare earths is a dirty business. Their ore is often laced with radioactive materials such as thorium, and separating the wheat from the chaff requires huge amounts of carcinogenic toxins – sulphates, ammonia and hydrochloric acid. Processing one ton of rare earths produces 2,000 tons of toxic waste; Baotou's rare earths enterprises produce 10m tons of wastewater per year.

And check out this interesting website from M.I.T. about the problems assciated with rare earths and which cites further sources.