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Alcoa Eyes Solar Industry
Posted by Big Gav on March 27, 2010 - 10:57am in The Oil Drum: Australia/New Zealand
The New York Times has an article on Alcoa's interest in making reflective solar troughs for the solar thermal power industry (Aluminium Maker Eyes Solar Industry), leveraging their experience in aircraft wing box design and replacing the reflective glass in parabolic troughs with aluminium.
Alcoa claim their all-aluminum parabolic trough (currently being tested at the National Renewable Energy Laboratory in Colorado) will cut the price of a solar field "by 20 percent due to lower installation costs".
Parabolic troughs focus sunlight on liquid-filled receivers suspended over the mirrors to create steam that drives an electricity-generating turbine. Parabolic trough technology has been in modern use in solar power plants since the early 1980s, but Alcoa executives said they saw an opportunity to refine the technology and get a foothold in the rapidly expanding renewable energy market.
“If you go out and look behind large parabolic troughs, you’ll find an elaborate truss structure,” said Rick Winter, a technology executive with Alcoa. “From our understanding of aerospace structures, we said if we can modify the wing box design used in aircraft and integrate a parabolic reflector, it would give us a light and stiff structure that would fundamentally affect the cost equation.” ...
Aluminum manufacturing, however, is the nation’s most energy-intensive industry, according to the Energy Department. Mr. Kerns said Alcoa had not performed a life-cycle analysis of the total energy costs and benefits of deploying such parabolic troughs, but noted that the company planned to use recycled materials to make the solar collectors. “We can take the energy intensity out, as much of the structural elements have the potential to use recycled aluminum,” Mr. Kerns said. ...
The Alcoa executives said the company planned to have its solar trough in commercial production within two to three years.
Alcoa Australia's WA alumina refinery expansion remains stalled because of an inability to obtain cheap long term gas supplies as a result of LNG exports limiting supply into the local market (the Varanus Island incident a couple of years hasn't helped matters either). However Alcoa has managed to obtain long term supply contracts for its refinery in Victoria - but using brown coal fired power - the dirtiest power source of all.
If we consider these 3 news items together it would seem that perhaps they should have looked harder at some form of solar thermal power (perhaps combined with gas or geothermal energy) for their Australian operations, using technology they have developed themselves...
Cross posted from Peak Energy.
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Well, Aluminium is used in aircraft to save weight, but there's not the same imperative on the ground. (Although presumably it would help reduce motive power requirements a bit when the structure had to be rotated towards the sun.) Aluminium also has corrosion issues, especially if disimilar metals have to be used used for fittings, bearings etc.
The box-girder design is a good idea though. Why don't we re-think the materials for lowest energy-input... since we don't work for a great big Aluminium smelter ("electricity congealer")!
;-)
What's the lowest-energy structural material? Plywood? (Aircraft have been made out of it very successfully, see http://www.liveleak.com/view?i=6dd_1257316562)
Obviously the reflector itself would have to be something shiny, scratch-resistant and corrosion-resistant (Stainless Steel? - or how would chromed plastic go?) but one could use quite a thin sheet of it if it was supported by a plywood box-girder structure and braced into a parbolic shape.
About the only problem that I can see is that it doesn't sound quite rocket-sciencey enough when the pollies come around asking questions on their ribbon-cutting tours.
Aluminium can be polished to achieve a high refectivity.It is possible that a corrosion resistant alloy can be used.Like all reflectors (and PV cells) they would have to be kept clean to maintain efficiency.
"they would have to be kept clean to maintain efficiency."
Jobs! What a concept.
Silver is much more reflective than aluminium (aluminum).
What about the purple/UV end of the spectrum? Those shorter wavelengths have more energy, and CSP can use light across the whole spectrum. If aluminum loses only 10% at the infrared end of the spectrum, and is much better at the UV end, wouldn't aluminum be just as good?
I think about half the overall energy is in the infrared, whereas UV is only a percent or two. So yes silver is better. But between cost, and the propensity to tarnish I don't think it is a good choice. Some deluxe telescope makers have a coating which is signiicantly better than aluminum (IIRC 98-99%), but it is so expensive it is only used for small secondary mirrors, not the large primary mirror. I think aluminzed Mylar is supposed to be a really good reflector (something like 98-99%), but it is pretty flimsy. In any case going for the last few percent is not likely to be worth it. A larger but less expensive mirror that costs less could produce the same system output for less money.
The solar thermal units that use Sterling engines, forget the name, use silver for the greater reflectivity. A few % of extra efficiency adds up over time to a lot. Initial costs are not high (200-400 nanometer thick layer).
From the NYT article referenced in the post:
What's the lowest-energy structural material? Plywood?
Bamboo. You could make a form and force it to grow in the form.
Extra points to weave multi-stalks together.
Carbon fiber might be a good option for a lightweight, lower-energy support structure.
As for Alcoa, could they build a solar plant to power their own aluminum smelter? Seems like a nature self-symbiosis....if a plant in AZ is attractive anyway.
according to their webiste alcoa gets 37% of their power from hydropower. using solar would be great. you're using hydro to build solar to use that solar to build more solar! don't think about that too hard.
alcoa in 2007 also opened up a plant in Iceland.
Alcoa's Hydropower Strategy Goes with the Flow
http://www.alcoa.com/global/en/about_alcoa/sustainability/case_studies/2...
"What's the lowest-energy structural material?"
Probably steel, if you take in acount the sunlight needed to grow a tree. It you don't, somebody already pointed bamboo. From those, (stainless) steel is preferable, since it will have a biger useful life, and thus save energy on the long run. You'd like to use some alcaline material where the steel meets the soil, to avoid corrosion. Concrete is the today preferred material, but you could use glass or some unsoluble salts.
The reflective surface can be as thin as needed. I see aluminium as the best candidate, but you'll need to insulate it from the steel, so you'll need some hydrocarbons. Even if you don't wat to use natural gas, those won't be very problematic, since they are needed on very small amounts.
I'd like to think I hate to be a smartass, but I don't. Sunlight is free, fossil fuels aren't.
Plywood!
Exactly what i was thinking.
It's like you say these guys still have no idea what is coming and want everything fancy fancy.
Weight on the ground is a minor consideration. It must be be perfectly balanced though on some used roller bearings.
And a thin sheet (really thin) of aluminium buffed to a high sheen would reflect pretty well. Corrosion could be prevented
by sealing it with a some clear uv resistant epoxy sprayed on.
It is all about getting the most bang for the buck
and in the long run maximizing EROEI as calculated for the TOTAL (mining all the metals, smelting, transporting, constructing, maintenance, etc)
The parabolic trough is simple enough but does anyone have technical details on the structure and workings of the collector tube?
Material, wall-thickness, working fluid, operating temperature, fluid flow rate etc?
One would think that you'd want its surface to absorb as much of the solar radiation as possible, conduct that to the working fluid running inside - while minimizing the heat-loss before it reaches the heat-exchanger.
For example is the tube just a straight hollow tube or is there any internal stucture to it like a radiator would have to lenghten the path of the fluid?
I don't think Alcoa are planning on reengineering anything other than the reflector itself.
You can find some details about collector tubes here :
http://www.nrel.gov/csp/troughnet/solar_field.html
http://en.wikipedia.org/wiki/Solar_thermal_collector
http://www.technologyreview.com/read_article.aspx?id=17169&a=f
Alcoa ins't working on tubes. Those are normaly made of stainless steel, externaly coated with a nikel oxide known as "black nikel" (you can search it on google, there are lots of companies doing it), and only as tick as needed to support itself and the liquid inside it. Toughts are normaly kept inside glasses, with the interior air drained, to lower losses from conduction. That black nikel is a material with very hight absorvity of visible radiation, and very low absorvity of infra-red, reducing loses from emission; even then, those are the bigest losses of the plant and thus, they are the parameter that normaly defines the temperature (it varies from one plant to the other).
You want to have as little absorving surface as possible, to minimize emission losses. That is why you concentrate light into a small through. And, now that you asked, I have no idea what is the flow rate of normal through plants.
If nothing else, aluminum is much easier for the do-it-yourself hobbyist. Making a parabolic reflector oven is on my to do list.
There's also an abundance of surplus Industrial Kitchen Stainless Steel sheeting out there, for those who want to make such things from recycled and abandoned materials. I've seen stainless kitchen stuff in dumps (full of bulletholes, though) that was shining like it was just polished..
Alas, most dumps don't let you walk thru and pick/buy stuff.
Liability and the hassle when the cops show up over someone who has a proper title to that car that is a cube.
(And yea - some great stuff can be seen at the dump.)
I very much doubt that much energy is saved in aluminum recycling. The melting point is 660°C, 1220°F. In the case of alloys, higher temperatures may be required.
Aluminum requires lots of energy, for production as well as recycling.
I imagine his point is that aluminium recycling uses much less energy than creating the metal in the first place - but as you say, it probably still consumes a substantial amount of energy in the recycling process.
Wikipedia says "The recycling of aluminium generally produces significant cost savings over the production of new aluminium even when the cost of collection, separation and recycling are taken into account." and refers to this paper :
http://www.world-aluminium.org/cache/fl0000181.pdf
If this technology is to scale to be a big-time renewable, then as far as aluminum markets are concerned, recycled or from mined sources - it has to come from somewhere. The price of aluminum will reflect the average energy content from all sources - so if doing a EROI study, perhaps just weight with the average recycled content of all aluminum produced.
The amount of heat needed to melt Al has got to be at least an order of magnitude smaller than "smelting" it, where the very strong Aluminum Oxyegen bond has to be broken. As an example of how energetic the Aluminum Oxygen reaction is Thermite was a popular world war two demolition tool. Thermite is a mixture of powdered aluminum and rust.The reaction reduces the iron and transfers the Oxyegen to the aluminum. So much energy is released that the resulting mixture of molten iron and aluminum oxide easily melts through steel.
In any case solar thermal plants have a decent EROI, so any embedded energy in their construction will be quickly replaced. We should be looking at costs, capital and operational as the relevant figure of merit. Capital cost contains, perhaps imperfectly, the cost of embedded energy.
Make energy expensive and you'll see how fast those industries based on melting deploy heat exchangers and reduce their use by a factor of 10.
Recycling aluminium requires only 5% of the energy of using the raw material. It's a disgrace that only about 30% of aluminium is recycled.
If nothing else recycling of aluminum at least eliminates the energy needed to mine the aluminum in the first place. I don't have any data but I suspect it is much less energy intense to recycle than it is to mine.
Check out Chris Jordan's photography
Cans Seurat, 2007
60x92"
Depicts 106,000 aluminum cans, the number used in the US every thirty seconds.
Think about that for a moment and let it really sink in...we're only recycling 30% of that then we are throwing away about 70,000 aluminum cans every second in the US. That's over 250 million aluminum cans an hour. Does any one else think there is something seriously wrong with that?
Wow!
If you cut up those 250 million cans and make them into refectors, at 200cm squared per can, that yields 5 kilometers squared per hour. In 400 hours you'd have a 100 by 100 kilometer square. So within about three weeks we would have enough reflector to build a solar thermal plant large enough to fully supply the United States power needs. Obviously supply of aluminum reflector material won't be the critical issue.
Um, yes, I think I "can" see it.
That's about 382 million cans an hour, or about 30 cans per American (including men, women, infants, and children) per day. That's a staggering lot of cans. So many in fact that it's undoubtedly yet another bog-standard example of the vast scaremongering exaggeration that always seems to enter discussions of this sort. These guys indicate about 1 can per day, a mere 3% of the 106,000 per second. Perhaps this Chris Jordan fellow is utterly innumerate?
Since we're dealing here in "proprietary" information, we'll never know the precise number for sure, but it seems to me that 30 cans per day is so over the top that it should have rung some alarm bells - but about plausibility, not about, say, running out of aluminum or being buried in it or anything of that sort. Then again, no one seems any longer to have any notion whatsoever about the plausibility of number they're bandying about. (The slide-rule era had plenty of demerits, but at least people were forced to know something about the numbers they were calculating, since the slide rule generally did not yield the number of places before or after the decimal point.)
Paul you are right. My bad. I actually copied and pasted right from his site and Chris actually said 100,000 cans every 30 seconds, not per second.
That's more like 12 million cans an hour.
Even so it is a hell of a lot of aluminum that's wasted.
Just consider the dumps a bank account, and you won't have to spend so much time bummed out, life is short.
What is this: 39.740074° -105.175890° ?
Um, the rough coordinates of NREL? I'm confused about what you're asking.
No, zoom in there and look real good.
It's the electrical "box" for the campus. You can see the high transmission lines running to the substation west of there. Which brings up this question: what is NRELs annual electric bill??
Ahhh,, who cares?
...
Apparently, no one.
how the fuck do these jokers... "renewable" energy? What the fuck does that mean? How does one go about "renewing" energy? Minor point I know (not), but it casts the entire endeavor as a bit of a joke, people. On you all.
ahhh,, never mind.
I do care, PDV. I care very much about hidden energy costs of designing, creating, installing and maintaining the so called renewable energies, which are largely underpinnned in a fossil fueled society. This is one of the many examples that we could take to see if a given energy source will be able to handle a society like our world society consuming today 12 billion Toes/year, out of them 80 percent from fossil origin and 86 percent not renewables.
The fact is that a certain measure of the EROEI of a specific source does not give in itself all the necessary clues to see if this given energy source has the ability to fed a given model of society with all its numbers inside (6.7 billions at present)
It is also a matter of the weakest link of the long chain of an increasingly complex society, in which if one of the factor of the ER numerator fails (an*a2*a3*...*an)the whole ER may become immediately zero.
And in this society, the so called renewables (in fact NOT RENEWABLE SYSTEMS able to capture part of the flow of renewable energy sources) are very much underpinned in the fossil fueled society. Are still heavily reliant on fossil fuels to be feasible; have a horrible assymetric interdenpendence on fossil fuels.
EROEI of a CSP plant can not be concluded just by a biased, interested study of an expert working for the company installing it. There are many other factors behind
There is a good description of Andasol's new absorption pipes here:
http://www.solarmillennium.de/upload/Download/Technologie/eng/Andasol1-3...
check out pp 16-17
EROEI is going to depend on longevity of the solar concentrator mirror. The longer it lasts the bigger the energy return. How long will an aluminum reflector last and how does that longevity compare other mirror materials?
http://en.wikipedia.org/wiki/Aluminium
Assuming a aluminum sheet thickness of 1mm, that's 40 kWh/m2.
The sun delivers 1 kW/m2. That's 262'800 hours in 30 years.
Assume an efficiency of 25% and a capacity factor of only 20%, that's 13,140 kWh/m2.
NEXT
Oh btw, this aluminum boat is over 50 years old.
And related question: Did they stop teaching simple aritmethics in English speaking countries?
Thanks for doing the numbers - and nice boat pic.
If you are going to make fun of our declining maths skills you should make sure you get your grammar / spelling correct though :-)
Auf wiedersehen...
Sorry, I'd prefer to write in my native tongue, but I'm afraid people will have even more problems understanding my native tongue than simple arithmetic's...
(And "Wiedersehen" is capitalized since it is a noun.)
anyone -
I'm glad you said that.
You may or may not be aware that I have for some time been wrangling with a number of people here at TOD who, as a matter of theology almost, insist on believing that things like wind turbines and solar power systems have barely marginal EROEIs and are therefore to be dismissed out of hand and not taken seriously.
As I have done here a number of times and in a number of ways, some very simple back-of-the-envelope calculations, even using highly unfavorable assumptions, can quite easily and convincingly show that such a supposition leads to absurd conclusions, such as the requirement of the equivalent of thousands of tons of coal to maintain a single wind turbine over its operating life.
But it is of no avail. If someone is dead set on believing something, all evidence to the contrary, there is little one can do.
"You may or may not be aware that I have for some time been wrangling with a number of people here at TOD who, as a matter of theology almost, insist on believing that things like wind turbines and solar power systems have barely marginal EROEIs and are therefore to be dismissed out of hand and not taken seriously."
I agree. the complications are tricky but solar and wind are great sources. there really are two calcuations. the energy payback time for the amount of energy used to manufacture the solar panel or wind turbine. then there is the dollar cost which is a bit more complicated. payback time of the actual retail costs of the solar panel and wind turbine is important too. there is more than energy resources going into alternative energy. there are human resources and other scarce resources.
The whole EROEI concept the way it is tossed around on TOD is sloppy and borderline useless.
Rgds
WeekendPeak
"But it is of no avail. If someone is dead set on believing something, all evidence to the contrary, there is little one can do."
There is one thing you can do, joule:
Hey! It's aluminum!
As with the discussion of aluminum cans above, beliefs trump math and science every time, especially since the broken education system ensurers that the average person is barely aware that math and science exist. IMO that's part of the blowback from when the hippies took over and decreed that from then on it would be politically incorrect and even punishable to attempt to educate anyone in anything substantial - or to keep score in games - lest the stupid and shiftless be "unfairly" exposed for who and what they are.
Don't know where you have been but precious few don't keep score in games, you ain't seen nothing till you dealt with an angry parent seeing their budding superstar benched.
IMO that's part of the blowback from when the hippies
Good thing you didn't say it was a humble opinion.
Now here's an actual scholar
http://www.historyisaweapon.com/defcon1/chomeduc.html
Now, you got anything to back up your 'hippy position'?
Sadly, reading that entire excerpt backs PaulS more than you might like to think, but Zinn has some good points. When I was forty-one I dusted off my discarded BS and used it for all it was good for--going back to school. I entered an intense one year secondary education certification program, which in reality wasn't all that good at teaching how to teach. Anyway at the end of it I had a good interview with the local school district and they were all smiles until I responded to their final question "Is there anything you would like to ask us?" Well having been a logger, commercial fisherman and carpenter and equipment operator, mill hand and an a myriad of other things in the twenty years since discarding my degree I had a penchant for honesty and getting to the heart of matters. I responded to the effect "Yes, just what is the product we are trying to produce?" Talk about killing an interview. It was like I had blown the ground out from under and eviscerated the interview panel in one fell swoop. It worked out for me as the panels expression change shipped me off to a local union hall. Talk about the cooperation/competition dynamic. Nothing like a union job site. As layoffs approach the whole the shift in emphasis from the former to the latter is palpable. Lots of old hippies ended up in the trades and they were damned competitive.
Sadly, reading that entire excerpt backs PaulS more than you might like to think
Err no.
There is a difference between what 'a hippy' is a defined as VS what 'a hippy' does.
An example that should create anger (because its religion) - Jesus.
If someone says 'they believe in what Jesus teaches' does that mean the Jesus of love or the Jesus that wants a fig outside of of Jig season and invokes a curse or tell you to sell some clothing to buy a sword.
Depending on why you are talking to saying 'I follow the teaching of Jesus' will mean different things to different groups. Go ahead. Ask for a definition of "a hippy" from the people of freerepublic. from quakers and from a functioning CSA.
The word "hippy" has not been defined.
No doubt. I deleted most of my original reply to PaulS where I pretty well insulted just about everyone I could on one side or the other of the term in two lines, just to point out how ridiculous the 'hippy' term was.
My point on the Zinn excerpts was more about his 'black hole' of competition and the implications on discipline when dealing with masses of pre through post pubescent humans. No doubt some fine creative juices get squashed out in the process, but... and this is no small item...humans have prospered because we have been able to cooperate and work well as groups. These days, in the first world, we are virtually one big group with, by definition, relatively few truly outstanding people. Doing most of the work that is required to keep this civilization rolling is not all that grand a way to spend time. Letting kids know its going to be this way early on in school may not be all bad. It is actually necessary. I've spent enough time subbing, both in long and short term assignments, in middle and high school classrooms to have an idea how hard it is to be a really good teacher--I'm not one. The near complete lack of explicit definition of what schools are to produce coupled with the near iron clad implicit expectations of complex society that the students are being prepared to keep running make the job of teaching all that much tougher.
Back to the 'hippy' thing.
'Hippies' was a label for a vast group that ranged from philosophical counter cultural militants with PhDs to drug spaced bums, but several years of early boomers who had the highest percentage enrollment in post secondary education (of all types) after leaving high school the US has ever seen and who also came to loudly oppose the Vietnam war (which likely had a whole lot to do with the high percentage of draft eligible men in deferment eligible education programs) are very likely the 'hippies' PaulS is referring to.
Well, considering that a CSP plant has an approximate split of costs (Source: Solar Paces) as follows:
Solar Field 45%
HTF System 7%
Power block 13%
Site Work and Infrastructure 3%
Services 7%
BoP 7%
Others 18%
A 20% saving in part of the Solar Field (the mirrors), may represent a cost reduction, if finally achieved, as mentioned by TNYT of about a 7-9% of the total plant.
Considering that in the meanwhile, the CSP plants could hardly go below 4 Euros/W installed, since the program of renewabvle energies started in Spain and that solar PV systems have decreased, in the same period from 5-7 Euros/Wp (fixed and with trackers) installed to slightly below 3 Euros/Wp (fixed plants) and that maintenance for solar PV (fixed plants) is substantially cheaper than for the mobile and pressurized pipes with synthetic fluids at 400º Celsius, I do not see a big advantage in this announcement.
Best places in Southern Spain for CSP plants have also some strong hail storms. The thinner the mirrors, the higher the probability of catastrophic damage. Spain is today the second country in the world, with about 4 to 6 GW of requested CSP plants and about 700 MW under construction, since several years, in different phases, but unfortunatelly only 110 MW were connected to the grid (fed-in) in January 2010, probably due to problems in energy storage and others, even Spain has plenty of R+D in this area and has made quite a good progress.
I had read about this a couple of months back. I had thought they were shooting for 50% reduction of the cost of the reflectors and an overall cost reduction of twenty percent. Fifty percent of 47%(the field) would yield a bit over 20%, so that interpretation might be consistent. In any case solar thermal plant prices I don't think have benefitted from economy of scale (of plant and industry) yet, so it is premature to use prices of existing small scale plants as prices for hypothetitical large scale deployment. I think they deserve funding with the intent of finding out how low the price can be driven in the future. Because of the possibility of thermal storage with solar thermal if it can be made cost competitive with PV, it would be a valuable component of the grid.
A couple of comments. Of course, economies of scale do not apply very much when talking about common hardware, that is what mainly composes a CSP plant. Steel, aluminum, cooper, concrete, tempered glass, synthetic fuel, etc. These have prices in the market and more volume does not help very much to reduce prices. Prices can be changed much more by speculating with these raw materials in stock exchange markets. So, you are quite right. Volume (economies of scale to which economicists are so much accustomed that they believe they are an universal law) will not help very much in this case.
Second, with respect to storage, if you look the molten salt tanks, similar to bull rings and go to the technical specs, you will notice that the biggest storage system, at least in Spain, has an energy buffer for about 8 hours. This hardly covers the night cycle of a winter day. Besides, with a couple of cloudy days, the gas turbines will have to enter to complement (Spain has an upper limit of about 15-17 percent in alternative usage, if the CSP plant want to be considered within the special regime and therefore, subject to premium tariffs. I do not see a great advantage and of course, I do not believe that huge amounts of electricity will never reach a molten salt storage solution. I do not believe that storage gives a competitive edge to CSP’s versus the PV plants. PV plants can also store in hydro dams by pumping up. The problem of electricity storage is the scale needed and the reduction of the overall efficiency.
When solar turnkey PV plants were in the range of 5-7 Euros /Wp installed and the raw materials prices were low, was when it was supposed that CSP’s could be competitive with solar PV plants. But the raw materials, as shown by Matt Simmons and looking into the markets, are very much tied up to oil and coal market prices and as oil becomes scarce, the CSP plants become less and less competitive than solar PV plants, where something like 50% of the turnkey is the solar cell (even this is also very much tied to energy consumption, but in a different scale)
Of course, economies of scale do not apply very much when talking about common hardware, that is what mainly composes a CSP plant. Steel, aluminum, cooper, concrete, tempered glass, synthetic fuel, etc.
Bullshit.
I as 1 man may be able to 'get' copper via picking it up off of the ground. I won't find steel just 'lying about'. I can, with some "simple" tools make iron from Iron Oxide. Both could be refined via elecrochemistry and all you'd need would be a switching power supply you adjust - you might even be able to pull 'em from old Xenon machines (the high current low voltage CPU plugable modules.)
But tempered glass? The setup for the 1st ounce of material will be very expensive. Depending on the syn-fuel it could be even more expensive to get the tools.
Economy of scale matters in the above examples.
It only looks like it doesn't matter because the world is awash in the materials all being made via "economy of scale".
You, worshipper of the economy of scale, try to be more respectful. Bullshit is trying to explain what can you do as individual with your bare hands, instead of going to markets to see if prices of steel, cooper, aluminium, or concrete decrease, at world level, when fossil fuel energy prices skyrocket. And then try to see how they influence to the final real turnkey price of CSP plants when oil is at $30/barrel or when it is at $83/barrel and coal and natural gas follow necessarily to oil.
It seems that you do not grasp well that raw materials depend very much on price of fossil fuels that make them available and that "economies of scale" worked while prices of essential fossil fuels were absolutely cheap and stable for years, which is not the case now and the main reason we are talking about alternative energies. Do the economy of scales applies to oil, gas or coal production, for instance? (that is, the more we produce and the more we progress in exploration, extraction, transportation and refining techniques) the cheaper the raw materials?
I think the argument is not can the raw material prices be made cheaper by achieiving economies of scale but can the price of the produced solar field components.
And I think you'd struggle to argue the cost of these has gone even a fraction of the way down along the curve, given that they have been basically bespoke manufacturing items up until now.
If eSolar and co can start selling plants in volume we'll see the costs of the components drop rapidly, is my prediction...
The key to this "argument" is what fraction of the cost of a current solar thermal plant is accounted for by basic materials (steel, aluminum, copper,...), versus what fraction is accounted for by low volume specialized manufacturing of the components, and what fraction is accounted for by engineering and design costs. Also current plants likely make inoptimal use of materials since it is cheaper to buy a pipe that is say twice as heavy as what you need, than have one of just the right specs created by speciality low volume manufacturing. It will take a rather large industry before the components of the supply chain are optimized, i.e. the volume of demand for the parts has been large enough long enough that someone has made the investment to efficiency supply them.
instead of going to markets to see if prices of steel, cooper, aluminium, or concrete decrease, at world level, when fossil fuel energy prices skyrocket.
What are "markets" supposed to prove here? What is "price" supposed to prove?
"Markets" prove here that economies of scale do not necessarily lead to an automatic and deep cost reduction, specially when a given system depends heavily on common industry materials (no rockcet science fortunatelly, because if sophisticated materials were used, then costs and prices will have another order of magnitude). Economies of scale are frequently used as a mantra to give faith in automatic cost reductions.
Auto car makers have a huge economy of scale with about 70 million units manufactured per year and car prices do not reduce costs drastically.
The improvements based in technology follow asymptotic curves and I believe we are close to the flattening side in metal or glass structures. Economies of scale depend always very much of energy sources powering the industry growth being kept stable and smooth in flow supplies, while production volumes increase. Ship building, urban constructions, aircraft industry, automobile industry, etc. etc. compete in the market with CSP’s in acquiring the basis for their activity.
And with respect to the fraction of the cost of a CSP, I believe it has been left clear by the comparison made by Solar Paces: Services are just a 7% and the other contents with very likely low content of labor in the rest of contents. The bulk is pure hardware. I do not buy the argument that pressurized pipes are made today much thicker than needed or that designs of metal structures for the trackers can be lightened very much, or that glass or aluminum mirrors can be thinned much more (and resist hail) or that storage tanks of molten salt can be reduced in size. The industry of pressurized pipes is very much advanced and CAD/CAM designs are already very much optimized.
I can not see in the Spanish experience any substantial cost reduction in more than ten years of intensive R&D and between hundreds of millions and billions invested. So, I do not see any fraction of the cost today of the CSP with respect to that of 2000. And I do not know what you consider "volume" for pipes or mirrors; each 50 MW CSP has one square kilometer of glass mirrors and thenths of Km. of pipes. Spain has more than 14 plants this size either constructed or under construction and about 80 times this standar 50 MW size already requested for license.
True. If the design has already been optimized and the engineering costs already paid for. I doubt either of these are true for solar thermal, there just haven't been enough megawatts manufactured yet. I suspect it will take several GW of capacity in operation before solar thermal has climbed the bulk of the learning curve.
8 hours far surpasses the millisecond or whatever you get with PV. At least the solar thermal system can do some load following. At a cost thermal storage capacity could be increased. If one plans to use NG turbines as backup, then storage sufficient to cover the startup time of the backup system would allow the NG backup to remain cold untill shortly before its actually needed. The loss of power from thermal storage being used up is 100% predictable. All other things being equal, for this reason a Joule of output from a solar thermal plant would have a higher system value then a Joule from a PV plant (unless the latter was closer to the point of use -but we are talking about large scale utility sources here). Either type of power could be stored externally. But this imposes an additional cost beyond the cost of generation.
Don't get me wrong. I'm a huge fan of PV. It is great at end user sites. I have panels myself. When it can compete against the retail power price instead of the price of bulk power far from the site of end use, PV has an unsurmountable lead. But for large scale (100MW to a few GW) power plants, those advantages no longer apply. I think we will need both PV at consumer locations, and largescale remote plants to satisfy the full potential of solar. Both technologies should be pursued until we have enough data to definately rule one out as uncompetitive. Even if solar thermal electric doesn't win out in the end, I don't think the investment would be wasted -as its usage for industrial process heat -or combined electric and process heat would be valuable in its own right.
you say:
"the biggest storage system, at least in Spain, has an energy buffer for about 8 hours. This hardly covers the night cycle of a winter day."
Implicit in your statement is an assumption that all sources of MUST provide power 24 hrs/day. This is not true. In fact, people do NOT use power at a steady rate. In fact csp power generation fits the footprint of actual use very well.
In those areas where csp is economical (i.e., places that get hot with lots of sunshine), most of the power is used in the daytime when csp is producing best. In the morning the sun comes up, and people turn on their a/c, In the evening, people turn OFF their a/c.
The existing 30 year old plants in California at Kramer Junction all have supplementary natural gas, which is burned to power the SAME turbines that use solar heat all day.
The result is that MOST of the power actually used comes from solar even tho they burn gas MOST of the hours of the 24 hour day.
I saw a chart of this provided by Abengoa, I no longer have the chart, and cannot give you a citation for it, but I seem to recall that solar provided over 70% of the power generated there.
The question of heat storage is simple economics, if fuel is cheap and readily available, then it makes little sense to pay for large storage tanks.
In Hawaii where all power plants burn oil (NOT natural gas), then it makes more sense to build more heat storage tanks.
The new Sopogy project in Kona uses csp with some storage:
http://www.hawaii247.org/2009/12/11/sopogy-introduces-new-solar-technolo...
http://jcwinnie.biz/wordpress/?p=6886
The new project in W Palm Beach FL will use csp to power an EXISTING gas powered plant.
http://www.nytimes.com/2010/03/05/business/05solar.html?hp=&pagewanted=all
In Hawaii we are paying 25cents/kwhr, and we WERE paying 45cents/kwhr just a couple years ago. Real costs determine the design of power plants.
Conclusion: beware of "all or nothing" thinking. There is no single answer to providing power, except of course conservation, which is cheapest of all.
Note: Please pardon my pontification, I used to be a professor.
I do not really believe I know anything about anything, it is just the way I express my thoughts.
Way to go !
Polished aluminum reflectors all exposed out on the Arizona desert. Humm..... Windy there, lots of dust flying about. Got to keep those surfaces clean or they will corrosion pit in no time. Sea salts, alkali salt beds from former lake beds, all those eat aluminum. I'd first do a chemical analysis of the desert regolith--note I'm not calling it "soil". How much salt and what composition is an easy quantitative hot water leach. Then a wind history study of the site, noting locations of any dry lake beds upstream of major wind directions.
oops, also have to worry about physical abrasion during wind storms. Higher off the ground, the better. Damn--they should pay me for this advice.
On the sunny side, at least the rainfall and humidity are usually low there. Like someone posted above, lots of jobs for panel dusters.
Editing to add: Australian deserts would have even more sea salt corrosion issues, being the world's biggest island.
Errr - Australia is as large as the continental United States - that last comment is just silly.
As for desert air issues, they are worth considering - but I think existing glass panels also get cleaned regularly and the panels are also turned down during wind storms to avoid damage.
Given eSolar's recommendation that CSP plants get built on brownfield sites near cities these sorts of issues may disappear anyway.
OK, how about the world's smallest continent? Frankly, I'd rather be the biggest than the smallest. Either way, sea salt will be a factor.