July 24, 2007
Renewable Energy Seen As Harmful To Environment
Jesse Ausubel , Director of the Program for the Human Environment at Rockefeller University, says that renewable energy sources are bad for the environment.
Renewable does not mean green. That is the claim of Jesse Ausubel of the Rockefeller University in New York. Writing in Inderscience's International Journal of Nuclear Governance, Economy and Ecology, Ausubel explains that building enough wind farms, damming enough rivers, and growing enough biomass to meet global energy demands will wreck the environment.
Ausubel argues that nuclear energy uses the smallest land footprint by far.
Ausubel has analyzed the amount of energy that each so-called renewable source can produce in terms of Watts of power output per square meter of land disturbed. He also compares the destruction of nature by renewables with the demand for space of nuclear power. "Nuclear energy is green," he claims, "Considered in Watts per square meter, nuclear has astronomical advantages over its competitors."
Ausubel sees the need for large amounts of land as the flaw with renewables.
On this basis, he argues that technologies succeed when economies of scale form part of their evolution. No economies of scale benefit renewables. More renewable kilowatts require more land in a constant or even worsening ratio, because land good for wind, hydropower, biomass, or solar power may get used first.
I gotta pick some nits here. First off, wind has economies of scale where the towers capture more energy the taller they get. Also, photovoltaics can be improved for conversion efficiency.
Hydro requires a lot of land.
A consideration of each so-called renewable in turn, paints a grim picture of the environmental impact of renewables. Hypothetically flooding the entire province of Ontario, Canada, about 900,000 square km, with its entire 680,000 billion liters of rainfall, and storing it behind a 60 meter dam would only generate 80% of the total power output of Canada's 25 nuclear power stations, he explains. Put another way, each square kilometer of dammed land would provide the electricity for just 12 Canadians.
Well, the steeper the drop the less land is required. The problem we have with hydro is we do not have enough steep drops and even if we did we'd be restricting the natural flow of huge quantities of river water and fish.
Ausubel sees biomass energy as terrible and I agree.
Biomass energy is also horribly inefficient and destructive of nature. To power a large proportion of the USA, vast areas would need to be shaved or harvested annually. To obtain the same electricity from biomass as from a single nuclear power plant would require 2500 square kilometers of prime Iowa land. "Increased use of biomass fuel in any form is criminal," remarks Ausubel. "Humans must spare land for nature. Every automobile would require a pasture of 1-2 hectares."
Some biomass wastes such as plant cuttings collected as part of trash collection could be used with little or no harm. But most biomass use competes with other species and basically takes food and habitat away from other species.
Again, Ausubel sees problems with wind. But can't wind towers be built on farm fields so that the same lands produce crops and energy simultaneously?
Turning to wind Ausubel points out that while wind farms are between three to ten times more compact than a biomass farm, a 770 square kilometer area is needed to produce as much energy as one 1000 Megawatt electric (MWe) nuclear plant. To meet 2005 US electricity demand and assuming round-the-clock wind at the right speed, an area the size of Texas, approximately 780,000 square kilometers, would need to be covered with structures to extract, store, and transport the energy.
At least wind towers would leave most of the ground area still available for wild plants and animals. Also, wind towers built off coast beyond visibility from land could leave land habitats undisturbed.
Ausubel finds fault with solar due to land area usage. But if photovoltaics were restricted for use only on existing structures (e.g. on houses, commercial buildings, and even on bridges) then the amount of additional land used could be minimized. The amount of area we'd need for solar power is two Ohios for enough solar power for the entire world. Though that's based on current world energy consumption and 10% efficient photovoltaics. We could create 50% efficient photovoltaics and then only put photovoltaics on human structures and get enough energy.
Update: For electric power currently our practical choices are coal (ugh), natural gas (dwinding in supply), wind (variable supply and not available everywhere), and nuclear. Solar is still too expensive. Though that will change. If you want to oppose some of these sources to the point of banning them or at least ceasing new construction then you've got to explain what else you'd want to use instead and how much more you are wiling to make us all pay to use your preferred alternative(s).
How about Geothermal, there is little environmental impact from that.
An MIT study of geothermal energy estimates there could be as much as 100 GWe of usable geothermal energy in the USA, assuming $1B in R&D over the next 15 years followed by proper infrastructure investments. That's not even enough to cover the new capacity we'll need by then, let alone replace the current infrastructure.
I broadly agree with Randall. The cliqued study justly condemns biomass and hydro energy, but neglects to consider the role of covering existing surfaces (roofs, outer walls, roads, etc.) with durable photovoltaic. There is no need to clear any new land for solar power if we just use the land we're already using more efficiently.
Wind's main problem is that vast swaths of the world do not have the steady, regular winds necessary for efficient wind power. Offshore wind farms are fairly ideal, but they can't answer the electrical needs of geographic interiors. I've often though that certain areas could become "wind power specialty" economies, the way Iceland is a geothermal specialty economy. I recall a windmap of the USA that suggested most of Alaska's souther coast (the Aleutian islands in particular) get a supply of wind right in the "sweet spot" for windfarms 24/7/365. That seems like a good place to invest an energy intensive business of some kind or another - just through up a couple windmills for a fixed cost and arbitrage their mortgage against the power savings.
Darn spell checker. I meant to say "the critiqued study"
The same land can be used for Wind AND Solar. Cover the ground with solar panels, leaving holes through which wind towers can come through.
Plus, this "two Ohios" of land is not a problem. The places with the most solar intensity are where the land is useless anyway, with little life that would be disrupted.
Unused land in Arizona and Nevada, Central Australia, the Sahara Desert, Saudi Arabia, etc. amount to more than enough to cover this much land with Photovoltaics, particularly at 40% efficiency.
What Robert M. said.
Expanding on the area "used" by wind farms, every wind farm I've ever seen has been in the middle of farmland. A tower base sits on a pad in a plot which is usually about 1/4 acre in size, and crops are planted right up to it. A large modern turbine might "use" an area about 4 rotor diameters on-center across and 10 diameters downwind. For a 100-meter rotor, this is 40 hectares or about 100 acres. Of this area, 99.75 acres would remain planted in crops.
Ausubel should be ashamed to show his face among honest people.
But most biomass use competes with other species and basically takes food and habitat away from other species.
To hell with the other species! It takes food and habitat away from our species.
Imagine the suffering that will happen when the rich and powerful in the third world (i.e. those with the most guns) get the idea that growing cellulose for biomass energy is more profitable than growing staple foods for the local population.
John Sokol said: How about Geothermal, there is little environmental impact from that.
But few areas are viable for geothermal, the working fluids are almost always strongly corrosive, with attendant high maintenance costs.
As to wind farms, yes, you can sometimes plant most of the area around them, but not all areas with suitable wind profiles are usable for agriculture. And you surely don't want to live in close proximity to a wind farm; RF issues, noise from the blades, etc.
There's no such thing as a free lunch.
And few are discussing the simple fact that none of the alternatives currently available are anywhere near ready to scale-up to meet the demand. Neither wind, solar, geothermal or biomass can generate the wattage or fuel sources needed to even make a dent in what we use in an average day.
I would love to see 50% efficient solar cells, or wind farms that produced more electricity than their fossil fuel counterparts, but this isn't a reality right now.
Nuclear power IS a reality right now. Those who preach of global warming and other inevitable environmental catastophes ought to be SCREAMING for us to increase our Nuclear power production.
I don't understand why they don't.
Just got to nit-pick. "Also, photovoltaics can be improved for conversion efficiency." That particular promise was all the rage when I was in college 30 years ago. Effeciency then - 10%-15%. Efficiency now - around 16%. I wouldn't hold my breath for any quick improvements on solar cell efficiencies.
Robert's "Strawman massacre" post is dumb. If Ausebel is really tilting at windmills, then why are people upset about China's massive dam project, and why don't we see see windmill farms sprouting everywhere? Because both consume a great deal of land. He can pretend that it's not a big deal, but that's still entire swaths of forests ripped out and species displaced that wouldn't happen with nuclear power. We can't pretend we can eliminate oil and coal with just corn and solar power without devoting huge swaths to land and that IS something environmentalists will complain about.
I think he has a point about Solar power, though. I don't see Solar Power fueling all of humanity's needs (without some kind of funky megascale project in space), but slathering solar cells atop urban houses to compensate for some of the energy homes use would be really helplful. It's like ahving a gas/electric hybrid car. No, it's not carbon free, but it's way better (and cheaper!) that what came before it. If his strawman point is that environmentalists aren't asking for a complete elimination of an oil economy, just a supplementing with renewables, then I think he makes a fine point... except for the fact that some environtalists argue for just that.
His comment about "preach to the demand side instead" is typical of head-in-the-cloud environmentalism. Al Gore can throw all the concerts he wants, and maybe America and Europe will even listen(!), but India and China and the rest of the developing world won't. So you either have to enforce it with Environmental Imperialism (good luck forcing that down the throat of the Thirsty Dragon), or give it up and try to address humanity's ever expanding energy demands with more energy (and more effecient products). Treating nuclear power as some kind of boogey man is just nonsense. Just. Nonsense.
I like the solar panels idea. I'm waiting for some city to mandate solar panels atop all government buildings, or even new private construction in certain areas.
Anybody seen the wind farms in Denmark and Germany? Bloody ugly, I tell you. Not an asset to the landscape.
I suggest you also not lose sight of all the manufacturing necessary (and all that entails in terms of mining, refining, disposal, etc) to build enough voltaics and windmills to produce the amount of energy that nuke plants would. In addition, what about replacement and disposal of old voltaics and windmills? Gonna put them in a big landfill?
Anyone unwilling to consider nuke plants isn't really green.
We must also consider the extreme unreliability of solar and wind energy sources. The sun goes down, the wind stops blowing. Both systems can go off line due to unexpected weather such as heavy rain. Since we cannot store the energy produced by these systems we must also have a 100% on demand backup energy source that can kick in when solar and wind power go offline. Therefore, the ecological footprint of solar and wind power must also include the ecological footprint of the coal, natural gas or nuclear facility that serves as its backup.
Frankly, until we can store the power produced by solar and wind power and produce it on demand 24/7/52 those sources will remain nothing but pipe dreams. People really need to grow up.
but Randall, what about all the millions of people that died when a very large earthquake went off beneath the world's largest nuclear reactor recently? can't the psuedo-greens throw that in the face of the pro-nuke argument?
and btw, why would anyone take Al Gore seriously about his commitment to reducing energy demand when his enormous estate is a big energy hog? or does he just mean the little people who admire him so much should stop using energy?
To second D.Boyd's point - where's this 5 fold increase in photovoltaic efficiency going to come from? An increase of that magnitude would by quite dramatic for a technology that's beyond its experimental phase.
If Ausebel is really tilting at windmills, then why are people upset about China's massive dam project...
For a host of reasons, including the fact that the river ecology is being destroyed, large populations have been uprooted without sufficient compensation, and the methane emissions from the drowned biomass will exacerbate climate change.
why don't we see see windmill farms sprouting everywhere?We do (and some people complain)
, except where some well-heeled opponents don't want wind farms interfering with their yachting hobby
Because both consume a great deal of land.
Some people want it blocked even when it uses no land at all.
Ausubel says: The amount of area we'd need for solar power is two Ohios for enough solar power for the entire world. .. based on current world energy consumption and 10% efficient photovoltaics.
I say: That is EVERY SQUARE INCH. The original computation of area was an estimate of the
coverage of all "highways, streets, buildings, parking lots and other solid structures in the 48 contiguous United States". Times two. This is a ridiculous, laughably unserious computation on a coctail napkin. Would you want to invest your savings with this person?
Ausubel says: We could create 50% efficient photovoltaics and then only put photovoltaics on human structures and get enough energy.
I say: Great. Then we only need to cover 2/5th the state of Ohio.
As a last thought: Thunderstorms, Tornadoes, locusts, and floods.
We could create 50% efficient photovoltaics
Actually, "could" is a completely inaccurate word here, because if we really could build cells of such efficiency in a cost-effective way, we'd already be doing it!
I am always suprised that discussions of renewables as replacements for conventional energy sources never address their potential for global climate change. For example, the energy produced by a wind turbine is energy that has been removed from motion of the atmosphere, i.e. the global climate system. Similarly, solar collectors gather energy that would otherwise find its way into the global climate system in the form of heat. Clearly, a few wind turbines or solar cells will not have any significant effect on climate. The same, however, can be said about a single coal fired generating station. I haven't done any calculations, but I think the laws of thermodynamics imply that using renewables to replace the energy currently generated by conventional sources will have a comparable impact.
Well, we have over 200 years of easily extractable coal in the USA, so I don't think running out is a huge issue Dave. So sorry to let reality intrude on your little pipe dreams - but if one doesn't consider the real costs (economic, health and environmental) of your little green pipe dreams we'll end up trailing China and India with nothing but a wonky electrical grid and blighted landscape to show for it. You strike me as a typical watermellon - green on the outside but just another pinko inside.
There is a quantum efficiency issue that limits solar cell efficiency to 40%.
As to wind farms, yes, you can sometimes plant most of the area around them, but not all areas with suitable wind profiles are usable for agriculture.
Not counting almost the entire Mid-West which is farm country AND wind country. Look at a wind resources map. The main problem is that the grid is sparse in those areas. To get the wind out I suggest HV DC lines. Let me mention that the Mid-West is why the USA is the Saudi Arabia of Wind.
To the other Simon,
For example, the energy produced by a wind turbine is energy that has been removed from motion of the atmosphere, i.e. the global climate system. Similarly, solar collectors gather energy that would otherwise find its way into the global climate system in the form of heat.
It all winds up as heat. Just in different places. Except for energy locked up in chemical processes. Which is not much. If it didn't wind up as heat it could be used to reverse global warming (which I think is not driven by CO2).
To Shanon who I love - at a distance,
Wind power production is distributed. Which means if distributed enough at reasonably good sites you can count on 20% of nameplate rating for base load. There are problems wind peaks at night. It also peaks in winter. However, at night in winter is when heat is most useful. Which says that when capacity gets large enough all electric homes should get an even bigger discount. All this will take some of the pressure off natural gas supplies.
BTW Shannon #2 son graduated from UC with honors. We are really proud of him!
What all this says is: Wind for the winter, solar for the summer. As the cells become cheaper. (big price reductions are coming down the pike).
JorgXMcKie said at July 25, 2007 03:04 PM:
Anyone unwilling to consider nuke plants isn't really green.
I'm Naval Nuclear qualified. I don't like the idea of all the circulating plutonium. And yes I have considered burning it in fast breeders. Let me restate: I don't like the idea of all the circulating plutonium.
I delete all Dave Mathews posts. So I deleted your responses since that only encourages him. He's the only one I always delete and I rarely delete anyone else aside from spammers.
Kyocera's solar cell efficiency gains sound like real commercial availability:
October 16, 2006 - Kyocera announced today that it has achieved a new world record of 18.5% energy conversion efficiency for a 15cm x 15cm multicrystalline silicon solar cell.
The achievement represents the latest in a series of advances by Kyocera, which in 1985 became the first manufacturer to commercialize multicrystalline silicon solar cell technology. Prior records for energy conversion efficiency in multicrystalline cells of this size were also set by Kyocera, including 14.5% in 1989, 17.1% in 1996, and 17.7% in 2004.
David M, an alternative interpretation, if you can hear it. Whenever anyone makes an argument to the effect that "this problem will not be solved unless people change - and it's deathly serious, so people better change," I find that the arguer cares more about the people changing than about solving the problem. This is true of hellfire-and-brimstone preachers, hunger advocates, homeless advocates - heck, just about any advocates. Extremist mullahs like to preach that if all muslims would just get with the sharia program and run their societies the "right" way, Allah would usher in a new age. This is not to say that they are always wrong in their desire, but that their self-deception gets in the way of real problem-solving and real personal change.
They are easy to recognise. They accuse their opponents of bad motives. They make apocalyptic predictions. They misrepresent their opponents' positions. They speak in false dichotomies. Any evidence of a small problem convinces them that their worst fears are Just About to be realised. Real Soon.
You are five-for-five. Consider the possibility that what you really want is for people to be like you, not to save humanity.
I think back to all the technology folks in the 1890s who predicted that we would be buried in horse shit. Didn't happen.
And that Population Bomb guy who predicted famines and mass starvation. Didn't happen.
In fact as wealth increases population growth stops and in many wealthy places it has even reversed. Bucky Fuller predicted this 70 years ago.
The pessimist starting with Malthus have had an almost perfect record. Perfectly wrong. Socialism has a pretty bad record. Unless of course you want a lot of dead people.
Capitalism strives to continually do more with less. It raises profits. Socialism has no such built in incentive.
Two words: ENERGY DENSITY.
As a serious pro-nuke kinda guy I can agree with the circulating plutonium issue, but what about things like helium cooled pebble bed reactors?
And here's some crossed fingers for that Bussard Fusion thing, although it looks like Arnold Schwartzenkennedy is going to invest a bunch of California's money in it, so it's probably a loser...
There is a quantum efficiency issue that limits solar cell efficiency to 40%.
For single junction cells in which each photon can produce only one electron/hole pair, perhaps. For more general classes of cells the only firm limit is that imposed by thermodynamics, which is in the high 90%s for sunlight and PV cells at temperatures near that of the surface of Earth.
I don't know if this guy's numbers are right, but I fear that his conclusions probably are. Sun and wind are just barely interesting by today's standards. If we can recoup some utility from the footprint we already occupy then great, but these diffuse trickles of energy are not going to carry us very far forward.
We know that the deep parts of nature contain energy beyond our wildest dreams. A hundred years hence the idea of collecting sunlight to power civilization will seem like the idea of running horses on treadmills.
M Simon: What's the big deal about plutonium circulating? It's hardly likely some terrorist in a cave somewhere is going to somehow magically be able to build their own nuclear bomb just because they have the stuff.
Nuclear weapons are an extremely complex technology that requires specialized knowledge and equipment to produce. You've had experience in the Navy-- do you think you could build your own nuclear bomb with what you learned working on sub reactors? Or even your own reactor, for that matter?
Solar is best in deserts, which have high albedo, .4 to .45 (globe average is around.3). How much area is needed? And what is the impact of changing albedo of "two ohios" from .4 to probably near 0 (and especially likely being in low latitudes)?
Nuclear weapons may be extremely complex, but at this point it's technology from the mid-1940s -- and a fair amount of the information is in the public sphere now. I doubt anyone in a cave could build a 'suitcase' nuke, but a gun-type U-235 device is so simple it wasn't even tested in 1945. Implosion is harder, but if people could do it 62 years ago with slide rules, the calculations shouldn't take very long on a Core2Duo, and shaping the lenses sounds like an ideal job for a computer-controlled milling machine. At that point all they're missing is a neutron injector of some sort and a timing system. I guess it's reassuring that North Korea was apparently unable to pull it off, though it's possible they were just testing the fission package of a staged thermonuclear device. Worry about for a while.
I'm also not going to explain how deadly and fear-inducing a plutonium-laced 'dirty' bomb would be, whether there was fission or not. At least Cesium-137 only lasts for 300 years.
Then again, trying to make anything out of PBGR fuel pellets is going to be a royal pain. I'm in favor of nuclear power.
If you want to worry about something being done in a cave, worry about biotechnology. Freeman Dyson is a big proponent of 'home biotechnology', but the risk of someone creating a real, lethal virus with their home biotech system dwarfs the risk from computer viruses. The H1N1 influenza DNA sequence is published, as is that of smallpox. String enough Gs, As, Ts and Cs together in the right (or wrong, depending on your POV) order and we're in a New World Order, of Hurt.
Kinda surprised that someone would oppose new nuclear plants based on "circulating plutonium". We are talking about the US here, AND new plants where on-site storage would be sufficient for decades, at least. I'm afraid the horse has left the barn, as it were, as far as "circulating plutonium". The former USSR is awash in nuclear materials. The idea that adding well controlled, well regulated, highly secure nuclear sites in a stable, democratic republic makes any change in the availability of nuclear materials for nefarious purposes is mostly fear-mongering.
When somebody starts looking for wayward nuclear materials from a new plant in the US, let's just say that the rest of the world will have gone through a herculean transformation regarding the security of nuclear materials. Almost unfathomable.
"It all winds up as heat. Just in different places."
Thanks for responding. The fact that it all ends up as heat in different places is exactly my point. Well maybe 75% of it anyway. Climate, at first blush, is nothing more or less than the response of a mix of gasses in the atmosphere to heat sinks and sources. Change the magnitude or location of the sinks and sources and you change the climate. If the changes are small, the corresponding climate changes are unnoticable. If one were to install fixed sources and sinks involving enough quads of energy to replace a significant portion of existing fixed and mobile fossil fuel burners, I would argue you may see very substantial anthropogenic global climate change. The more so, because the thermal efficiency of the renewable substitutes are so relatively low.
The entire world consumed ~20 trillion kWh electricity in a year. Probably, we'll never need more than 100 trillion kWh. Let's assume 100 trillion.
The different renewable energy sources, in fact, are just one source: the Sun. Wind blows because of the Sun. Biomass grows because of the Sun. Photovoltaics work... well... surprise... because of the Sun. The Sun delivers anually 1000000 trillion kWh of energy to Earth, i.e. 10000 times more than we are going to harvest.
I hope this alleviates your concerns.
While raising valid points, I think the Ausubel study is over-reaching in its conclusions. This is unfortunate because they had an opportunity to make an important point that a lot of people need to understand, namely, that ALL energy sources, including renewables, have some problems. With renewables, it is fairly large land use (i.e., a high "footprint") in addition to the intermittentcy and cost problems. Even renewables do not have zero environmental impact, and this is something that a lot of people currently do not seem to understand.
However, because the study over-reached in its conclusions, and made the dramatic (and unpopular) statement that nuclear is far better than renewables even from an environmental persepctive, I think they just turned a lot of people off. This results in them not listening to the message at all. Sometimes, if you say something that is far from people's preconceived notions, they will simply dismiss you. In those situations, you have to bring them along slowly, one step at a time.
The real truth is that both nuclear and renewables have very small environmental impacts compared to fossil fuels. Thus, we should persue both, and the goal should be reducing fossil fuel use as much as possible.
Concerning proliferation, I believe some caution SHOULD be shown with respect to starting new nuclear power programs in nations, especially ones that are less-developed and/or potentially unstable. We certainly shouldn't consider giving them fuel cycle (i.e., enrichment or reprocessing) facilities. I agree with the GNEP idea being floated around where we would not allow many more of those facilities, beyond what already exists today (in developed nations with full UN monitoring).
All that said, merely adding more nuclear plants to nations that already have plants and/or nuclear weapons has absolutely no effect at all on proliferation. This is true whether or not we reprocess or not (although in the once-through case it is even more obvious). The simple truth is that it will always be easier for a weapons-seeking nation (e.g., Iran) to simply build its own enrichment facility and enrich its own uranium ore than it would be to surreptitiously reprocess spent fuel from a domestic reactor, or to somehow steal plutonium bearing fuel from abroad and then process it. The Iran example clearly shows this. The plutonium in commercial reactor spent fuel isn't very useful for weapons anyway, due to the isotope distribution.
It is not the size of the US spent fuel inventory (i.e., insufficient quantity) that has prevented it from causing proliferation. The quantity is ample; it's the difficulty in obtaining plutonium from this source that is keeping it from being stolen/used. Thus, adding some more to the spent fuel pile will not increase proliferation risk at all.
In terms of dirty bombs, not only is reactor spent fuel material infinitely harder to obtain than the radioactive sources used in labs, hospitals and industry, but it makes a much less effective RDD, due to its relatively low radioactivity concentration, and its less dispersible form. The sources used in hospitals, etc.. are much more concentrated and are often in the form of an easily-dispersible liquid or powdered solid. They are stored in small, shielded containers that allows one to easily lift, hide and transport them, w/o serious radiation exposure. Reactor spent fuel assemblies are ~15 feet long, weigh almost a ton, and require a ~100 ton shielding container if one is to avoid receiving a lethal dose as well as setting off all the radiation alarms all over the plant site. Bottom line, the dirty bomb (RDD) risk from nuclear power will always be negligible compared to that which exists from medical and industrial sources.
"Whenever anyone makes an argument to the effect that "this problem will not be solved unless people change - and it's deathly serious, so people better change," I find that the arguer cares more about the people changing than about solving the problem."
I think this is an extremely insightful statement. I've had these thoughts myself. It's true for at least some of the environmental purists out there. I've been in blog debates where anti-nukes have let it slip that one reason they don't like it because it doesn't require people to change their "profligate" behavior.
Some of them really have some serious social engineering in mind, and they're actually hoping that the very real problems with fossil fuels will force us to make these significant lifestyle changes. Then some engineers come along (as they often do) with a technological, "black box" solution to the environmental, limited resource, and geopolitical problems with fossil fuels (namely, nuclear power) that doesn't require any changes in lifestyle, and lets us continue to "get away with" our "profligate" behavior. This infuriates them.
A good analogy here is the attitude of religious conservatives (e.g., the Catholic church) towards birth control technology. It solves most of the real problems while letting us get away with "bad behavior". Once again, it's more about the desired changes in behavior than actually solving the problems that the behavior changes were originally there to combat.
Greg - Thank you for your response. However, like M. Simon's response, it does not alleviate my concern. With all due respect, if I was concerned that increased use of renewables will somehow prematurely drain the sun of its energy, you would have alleviated my concern. That is not my concern; the sun will die of its own accord in its own good time quite independent of anything we do here on Earth. Let me try again to explain my concern from a slightly different perspective.
A large number of people, including some scientists (who I believe should know better), are in a virtual panic over the thought that global climate is such a very delicate system that current human activity is permanently altering it so completly that we are now standing in Death's Doorway. Not to put too fine a point on it, what they are saying is that the CO2 from existing use of fossil fuels combined with a few cow farts is changing the climate to make the Earth uninhabitable.
It should be obvious from my tone that I tend to disagree. However, I could be very wrong. So, let us assume for the sake of arguement that global climate is, indeed, a delicate system that can be affected significantly by the thermal effect of the CO2 and methane emissions that result from our current eating habits and use of fossil fuels. What I am suggesting is that substitution of renewables for this fossil fuel use might have a greater thermal effect on those aspects of the atmosphere that we call climate than what they replace. Personally, I suspect it is likely.
FWIW, I am a retired physicist with more than 30 years of experience in varions facets of the energy industry. I have thought (actually, mused is more like it) about this often, but never deeply. I was hoping someone here had given the matter some real thought.
Greg - On re-reading your comment, I find that I missed your point which seems to be that we will never use more than a tiny part of the the energy that the earth receives from the sun so there's no need to worry. I agree with that basic thought, but as the second paragraph of my response to your response should explain, it still does not alleviate the concern I am raising.