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Solar Singularity

Is it approaching? A nickel a kW-hr would be pretty hard to beat.

Like Phil Bowermaster, this kind of thing is why I don't lose much sleep over peak oil.

[Update a few minutes later]

A lot of comments on the subject over at Randall Parker's place.

 
 

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45 Comments

Jim Harris wrote:

It doesn't matter whether or not you "worry". The truth is that we will be paying more and more for oil until and unless we use less. You were mentioning these big new sources oil that are going to come on line. Sure, there will be some, but that by itself will not prevent a squeeze, although it may lessen it. Because, first, almost all of the conventional oil wells in the world are slowing down, so something has to replace them just to hold even.

Second, even if you hold the total even, you're losing ground per person: Both the world population and the United States population grow by about 1% per year. Most of the discussion of peak oil cites the total world supply, without dividing by the world population. But if you do take that ratio, the world oil supply, per person, peaked around 2005. In order to hold even per person, the world oil supply would have to go up by 800,000 barrels per day per year. No one is firmly predicting such a large overall rise ever again.

In fact, even 1% population growth is not the right yardstick. About half of the world population still lives in the early 19th century, with minimal access to electricity, paved roads, and running water. But that fraction is decreasing. The world's modernized population is increasing at 2-3% per year. If 800,000 more barrels of per day per year is a bridge too far, 2 million more barrels per day per year is at the far end of the canyon. It won't happen. Modernized people, the sort of people who can afford a refrigerator, WILL use less oil each. That mandate is why oil is now over $100 per barrel. The only surprise is that world modernization is coming faster than expected.

Those are just the facts, but I'm not "worried" either. I'm not worried because I don't drive an SUV. I don't think of a Prius as a hairshirt. After all, if solar power did come on-line, it would replace coal and not oil, so we would need plug-in hybrids to make use of it. I'm not worried because I planned for the future by listening to environmentalists.

Rand Simberg wrote:

I plan for the future by listening to the people who are actually creating it.

Mike Puckett wrote:

Rand, that is quoteworthy. Is that an original Simberg?

"After all, if solar power did come on-line, it would replace coal and not oil, so we would need plug-in hybrids to make use of it. I'm not worried because I planned for the future by listening to environmentalists."

If we hadn't listened to the environmentalistst, coal mining and ripping the tops off of mountains would be obselete, nuclear would provide our baseload and we would be using the outer continental shelf and Alaska as a production buffer.

Thanks to them, now we can use something else for the electricity and contiune ripping the tops off of mountains to feed shiny new coal to liquids plants! Yay for unintended consequences the moonbat hypocrites will never own up to!

Jim Harris wrote:

I plan for the future by listening to the people who are actually creating it.

That's fine, that is what you should do. But which future? It will take years to live down the false future of ever larger cars and houses, and ever more plane flights, oil wells, and coal mines. The real future belongs to companies like Google and Vestas.

For that matter, do you expect your rockets to be solar-powered?

memomachine wrote:

Hmmm.

The future belongs to a search engine company that derives it's income from advertisement?

Well, well, well. I can at least thank God you didn't invoke AOL.

Tom wrote:

Assuming the picture on the web page is more than marketing hype, the design is interesting. Fresnel lenses on the front and heatsink vanes on the back. Though they can't gather more than the surface area of the panel...it'll be interesting to see inside. Energy storage will still be an issue, but taking some of the peak load during the day is something not to be sneezed at.

I also like the RS quote. Hope it's an original.

Ah. I see JH is back again too. Solar thermal rockets have been proposed for deep space application:

http://en.wikipedia.org/wiki/Solar_thermal_rocket

And don't forget solar-ion, commonly used in comsats nowadays and also on the Dawn mission:

http://dawn.jpl.nasa.gov/

Low thrust, but excellent efficiency.

Tom wrote:

Sorry to see you've gone to moderated comments, though I think I understand the reason. At least it got rid of the 500 page.

Brock wrote:

Rand, in all fairness, solar and peak oil have little to do with each other. No one uses oils for electricity on any scale. However, I'm not worried about Peak Oil either, and I have a one word answer for why not: algae. It's 100x more efficient than soy or corn, can grow in saltwater and throws off edible food as a by-product.

As for energy, I have my doubts about solar as a "total solution." Sungri will be great for dry, sunny areas that get lots of sunlight and never have clouds, but where I live? Not so much. And I live in the lower 48, let alone those poor bastards in Canada or cloudy England.

Similarly, wind is plentiful globally but can be very limited depending on locality. Right now I'm thinking the only long term solutions for the whole planet are getting serious about nuclear or someone figuring out how to do fusion for net power.

Rand Simberg wrote:

I haven't gone to moderated comments (at least any more than I ever have, since the MT upgrade). Occasionally, MT will hold a comment because it thinks it's spam. It was probably suspicious of your post as a result of multiple links.

Tom wrote:

Ah. I knew something was up when I got the 500 error on my 'sorry' post.

Great discussion at RPs.

Bill White wrote:

The future belongs to a search engine company that derives it's income from advertisement?

Not the entire future (heh!) but,

When in the course of human history have so few people made so much money with so little start up capital (relatively speaking) and all in such a short period of time (without violence)?

Microsoft is one contender, of course.

And now the battle is joined:

Free + advertising

versus

You buy our software

Bill White wrote:

Concentrated PV blended with solar thermal to harvest the waste heat (the link says Sungri is looking into patentable ideas to use the waste heat) would be an awesome hybrid.

Seems ideal for solar ion propulsion, lunar base power needs and maybe even JP Aerospace dirigible to orbit.

Can you make Fresnel lens from transparent aerogel?

I recall a University of Wisconsin Vomit Comet experiment showing that aerogels made in zero gee are clear while areogels made in gravity have a colored tint.

THAT could be an interesting zero-gee manufacturing idea if the follow up experiments confirm the experiments I recall reading about.

Kelly Starks wrote:


Personally, Iím more excited by Bussards success with his polywell reactor, but thatís an aside.

I seriously canít get that excited about solar. It can produce electricity in some places at some times a day Ė if your willing to lay waste large acreages, with associated ecological impacts. Course most users and growth in power consumption arenít in those areas (and the storage issues a big price driver), so its kind of a moot point.

As to Oil (using off my head numbers), only about half is consumed in a fixed system you could connect to a grid. Something less then a quarter is consumed in cars and trucks, so doubling you gas mileage in a hybrid, in the face of a projected quadrupling of world demand in the next 50 years, isnít going to help any.

Personal nit. We have enough known reserves in the US and its surrounding oceans to make the US a oil explorer, but every time someone asks for drilling permits, the argument is that ď..production isnít the answer Ė conservation is the answerĒ.


As to what we fuel rockets with -- ??
Liquid oxygen involves refrigerating air, and Hydrogen means breaking down water. As for in space -- well water and oil are highly common in the inner solar system. Some individual NEOís have the oil of ten times OPECS best year in them.

.. now that would be a weird killer app for space industrialization. Oil recovery and export to Earth.

;)

Karl Hallowell wrote:

Jim, you wrote

The truth is that we will be paying more and more for oil until and unless we use less.

Sounds to me like the disease is the cure especially in the presence of markets which handle quite well the problem of scarcity.

You also wrote:

It will take years to live down the false future of ever larger cars and houses, and ever more plane flights, oil wells, and coal mines.

So it takes years. What's the problem? Lots of things take a long time to achieve.

Paul Breed wrote:

>It will take years to live down the false future of >ever larger cars and houses, and ever more plane
>flights, oil wells, and coal mines.

With a few bumps along the way all of human history has been a continious improvement in our standard of living. Why should we give that up?
That seems to be a defeatist attitude.

Let's work on solutions that keep this improvement going rather than some amorphous guilt feeling that we really don't deserve what we have and that we need some nanny to reign us in.

The nanny's have caused much damage and their poisonous ideas continue to have bad unintended consequences. (AKA Ethanol, and food riots.)

Orville wrote:

Vesta = Vespa? If so that will be a mighty chilly commute in the winter.

Li-on battery technology has come to the place where I'm looking into building my own little three-wheeler just for fun. When I see applications like Killacycle.com I think it's about time for hobby builders.

The Killacycle electric drag racing bike uses A123 batteries scavenged from Black & Decker Li-on battery packs and does the 1/4 mile in 7.824 seconds at 168 mph with enough juice left for several more runs, and still only takes a short time to recharge. The battery pack only weighs 180 lbs.

Dennis Wingo wrote:

Just like with rocketboys, extraordinary claims of cheap costs need verification. I noticed that to get to their numbers they require a factor of 1,600 suns for their solar cells.

Here is a prediction. The materials won't take it.

The 1,600 suns x 1,000 watts/m2 = 1.6 million suns.


Paul Breed wrote:

The 1,600 suns x 1,000 watts/m2 = 1.6 MW m^2

If the cell area is 1cm then we have 160W,
reasonable. The overall module would be 40 cm sq
sqrt(1600) *1cm.

The power delivered would be 0.35 *160 = 56w heat would be ~ 104W in an area 40cm or 15.7 inches square, also reasonable.

Passes the reasonable test....

Can we control the thermal conditions?

Lets assume that the special nano material fluid is as good as solid aluminum 1cm square, also assume its effectively 1/2cm thick. For 104W we get 22 degrees C rise. High, but not unreasonable a lot of power electronics runs at much higher thermal and energy densities.

So far everything passes the small test.
Realize that the freznel lens will contribute to the inefficiency so the thermal efficiency conduction numbers under the actual CELL will be conservative.


Frank Glover wrote:

"For that matter, do you expect your rockets to be solar-powered?"

Many people are looking into solar-driven ways to break water into H2 and O2. Rocket operators (among others) using that combination would benefit. So there's a conditional 'yes' there...

Dennis Wingo wrote:

I meant 1.6 million w/m2 of course.

160 w/cm2 x 40 = 6400 watts.

at .35 (the efficiency) = 4160 watts thermal dissipation in 40 cm square.

Paul F. Dietz wrote:

I expect 'peak oil' to be handled by some combination of increased efficiency and massive investment in coal-based synfuels. At current prices of liquid fuels, coal-derived synfuels are almost obscenely profitable. Moreover, a good chunk of the world's coal resources are not exploitable by conventional techniques (too thin, too deep, under water, etc.) but could be accessed by in situ gasification. The syngas from this would be, after cleanup and shifting, well suited for synfuel production.

Rand Simberg wrote:

Actually, once you get into orbit, there are lots of interesting concepts for solar-powered rockets, both solar thermal and solar electric.

Robin Goodfellow wrote:

1. Why "peak oil" is bunk:

As prices for oil go up the profitability of new sources of oil, such as tar sands or coal gasification, becomes possible. Now, here's the important part: as investment into exploiting those new sources increases the technology of using those sources gains greater and greater maturity, and begins decreasing the cost to exploit those sources. This is the key, the price of oil tomorrow is not about exploiting resources with the technology we have today, it's about exploiting resources with the technology we have tomorrow. High oil prices drive r&d of new technologies for exploiting new sources of oil. This is not even a new phenomenon. As oil prices have gone up from time to time in the past new technologies for getting oil out of the ground have been invested in, and ultimately reduced the overall price of oil.

Note that the potential sources of hydrocarbons that may be profitable to extract given reasonable technological breakthroughs exceeds the current "proven reserves" of oil by several orders of magnitude.

2. The real problem with solar energy is and remains the issue of availability of power. People don't use electrical power at exactly the same times as when solar power is available. Until there is a better way of storing electrical power, solar power cannot be a dominant energy source.

Paul Breed wrote:

You are multiplying by 1600 twice.
You only get to do this once....

At the surface of the 40 cm square module there is 1000W/m The 40 cm module is 0.16 sq meters.
So at the surface there is 160Watts, this is concentrated down to 1cm sq (in my example)You don't feed the assembly a 1600X sun, the assembly concentrates the sun 1600 times before applying it to the active cell. The outer surface of the module is at 1 sun, the freznel lenses concentrates it 1600 times internally to the module so they only have 1600th the square area of expensive triple junction cell.

So the 1sq cm has 160 watts, not 6400.
Also note that you cant scale linearly 40cm square
outer cell has 1600 x the area not 40x.

Track your units...


IMHO this is Solar's problem, even if we had free 100% efficient solar cells and 100% efficient energy storage, the amount of area needed to gather the power of one single nuke plant would be 8200 acres.
If you use real current efficiencies and storage efficiencies then it would take 186,000 acres or 290 sq miles. That is a solar plant 17 miles on a side.
That is to replace one nuke plant.

(Replacing Japan's Kashiwazaki nuclear plant assuming 1000w/m^2 and 6 hours of effective sun, For real world I'm assuming cell efficency of 11% and storage of 40%.)


Karl Hallowell wrote:

Paul,

First, the Kashiwazaki plant is supposedly the largest nuclear plant in the world (according to Wikipedia) with generation capacity of 8.2 gigawatts split among seven reactors. Further, it occupies 4.2 square kilometers which turns out to be 1,038 acres and dumps heat into the Sea of Japan, which means a certain amount of ocean is also off limits. That means the unrealistic 100% efficient solar cells, always perfectly lit, compare well to nuclear power.

Second, it depends on location and efficiency of the solar cells and storage solution. The above is reasonable for a late 90's system. There's a very good chance that the Sungri system is vaporware, but if not, it's not likely to be that low in efficiency.

The solar cells are probably above 15% and storage is probably a bit closer to 50% due to better transportation efficiencies (you can get 3% per 1000 km for that much power). There are more efficient storage systems, but they drive the cost of the overall system up considerably and aren't viable for a $0.05 per KwH system. My take is that the acreage would probably be under 140,000 acres mostly due to improved solar cell efficiency. In many places, you have near perfect weather and would get an average of 8 hours of sunlight per day (we're ignoring sun tracking which tends to be expensive). For a near optimal location, the acreage is now under 115,000 acres.

Moving on, this is a poor use of solar power since you're attempting to replace an always on power source which is the most difficult for solar power to do since it only is around half the day (and storage is so inefficient). The usual approach is to use solar for peak times of the day and to smooth out remaining fluctuations with hydro power (which also is the most common form of power storage). So up to a point, you don't need storage (depending greatly on how much hydro you have). If all of solar power could be covered this way, you'd virtually eliminate the need for storage and drop acreage to under 60,000 acres (but you'd probably need several gigawatts of hydro on top of this which probably would need to be within a few hundred kilometers of the grid supplied by the solar cells).

Finally, I wonder if there is a way to harvest the excess heat economically, say by circulating a heat transfer fluid between the solar cells and an underground reservoir. If so, not only can you boost the effective efficiency a little, but you have a way to generate power at night, by reversing the flow and using the solar cells as radiators. Any power that you can generate at night would reduce your power storage needs a little.

Karl Hallowell wrote:

Huh, at Future Pundit (as linked above), Randall Parker was saying that the solar cell used had an efficiency of 37.5%. If true, that does mean roughly a factor of three reduction in area. Very impressive, if they can do it.

Jay Manifold wrote:

"I'm not worried because I planned for the future by listening to environmentalists." Possibly the biggest JH howler yet ... although "the false future of ever larger cars and houses" is a serious contender. With the possible exception of Hal Lindsey, no one has a worse record of predicting the future than "environmentalists." Question: is Jim Harris over the age of 18?

Free advice: plan for the future by listening to Ray Kurzweil and Eric Drexler. Kurzweil, in particular, has a good handle on why "[t]he only surprise is that world modernization is coming faster than expected."

Dennis Wingo wrote:

Paul

Thanks but that was the point. In 1 square cm, which is .254 inch by .254 inch, there is 160 Watts. I thought that what was being said was that there is 40 square cm.

160 watts per square cm is a hell of a lot of heat concentrated in a small area. That is going to result in far more than 104 degrees C in heat on that area.


Jim Harris wrote:

So it takes years. What's the problem?

A husband and wife are on one of their frequent skiing vacations. The husband says to his wife, "You do realize that if we keep flying here, we're going to lose our mortgage?" So his wife answers, "Oh, I'm not worried about that. I'm sure that the market will fix it. Wanna hit the slopes?"

Yes, whatever the problem is, you can always fatuously declare that the market will fix it. Which it will, just not necessarily in your favor. Or you can always vaguely declare that you're not worried, without addressing the purpose of ever worrying about anything.

So yes, it is true that the market will fix the problem of peak oil. But not in America's favor, since our energy die was cast by glib people who just don't feel like worrying. Vice President Cheney, for instance, dismissed conservation as a mere "personal virtue", but now the market is going to make it national policy.

The market will also take care of "SUNRGI" by ignoring it. It has very little credibility.

Karl Hallowell wrote:

So what's your problem, Jim? It may be a glib observation, but it is a correct one. Unlike the husband/wife story, if the market does something that's not in my favor, then I change my behavior.

So yes, it is true that the market will fix the problem of peak oil. But not in America's favor, since our energy die was cast by glib people who just don't feel like worrying. Vice President Cheney, for instance, dismissed conservation as a mere "personal virtue", but now the market is going to make it national policy.

Once again, the disease is the cure. As the price of oil and its products goes up, demand for oil will go down and alternatives will be used. Even if it is as you say and government is sticking its head in the sand, the US and indeed the world is far more than its governments. We don't depend on government to decide how we live our lives or run our businesses. Those that anticipate such changes will do well, the rest will have to muddle along.

Dick Eagleson wrote:

Mmmm, Dennis I think you'll find that a square centimeter is actually .394 inches on a side, not .254 inches. You need to divide 1 by 2.54, not 2.54 by 10.

mz wrote:

But "the market will fix it" is used because the advocates implicitly mean the "fix it" part means your lifestyle will not change.

If you take your argument to the ultimate conclusion, everything happening ever anywhere is "the market fixing it". Big bang, formation of earth, the murder of John F Kennedy, Katrina... I becomes so broad it doesn't have any content or prediction power anymore.

Rand Simberg wrote:

But "the market will fix it" is used because the advocates implicitly mean the "fix it" part means your lifestyle will not change.

What utter nonsense.

It doesn't mean that at all. It simply means that our lifestyle won't change by government fiat.

Jim Harris wrote:

Unlike the husband/wife story, if the market does something that's not in my favor, then I change my behavior.

But this is not about you personally. You know very well that there is a great deal of government policy to protect, reinforce, and subsidize the American automotive culture. Moreover, you know full well that oil demand is extremely inelastic in the short term. There is no such thing as no government oil policy, and those who pretend that there is are really arguing for the status quo. This year oil imports will be a $450 billion cash transfer from the US to foreign countries. That financial penalty does reflect decades of indulgent government policy.

If you still argue that sure, SUV owners will pay through the nose but you won't, that's partly true and I've been talking that way too. But it's partly not true, because a lot of our indulgent oil use is woven through the economy, and it will affect your salary and the prices of anything that you might want to buy, unless you emigrate.

RKV wrote:

Gonna have to keep those lenses clean to maintain efficiency folks. Not a show stopper, but operational experience should inform us on just how efficient the conversion process stays over time.

Ed Minchau wrote:

Right RKV. However, maintenance is an issue no matter what power generation system is used. Keeping a lens clean is fairly simple compared to the mainenance required for a hydroelectric or nuclear plant.

Jim Harris wrote:

Gonna have to keep those lenses clean to maintain efficiency folks.

This is really missing the forest for the trees. These guys came up with a moderately clever design, not clearly better than anyone else's but pretty good. Then they plucked 5 cents per kWh out of thin air. Whether it's just spike or long-term, the high price of oil is real. This press release is just talk.

mz wrote:

What utter nonsense. It doesn't mean that at all. It simply means that our lifestyle won't change by government fiat.

So drastic possible effects like big inflation or lowering of real income from peak oil ^d^d^d the market fixing peak oil are possible?


I personally view it actually most likely that it will go to synfuels from coal without carbon capture and a very fast CO2 rise will result. But it's really hard to know about the oil reserves with any accuracy so time estimates are all over the place.

Karl Hallowell wrote:

If you still argue that sure, SUV owners will pay through the nose but you won't, that's partly true and I've been talking that way too. But it's partly not true, because a lot of our indulgent oil use is woven through the economy, and it will affect your salary and the prices of anything that you might want to buy, unless you emigrate.

You still don't get it. Expensive oil prices will affect everything that depends on oil. In the short run, yes, it means more expensive stuff in general. That also means great incentive at every level of the economy to use less oil and to switch to substitute goods instead. So yes, it'll be unpleasant, but it is enough. Again why do we want to fix what isn't broken?

joe wrote:

my bet is that the sunrgi system is vaporware.

I took a solar installation class about 7 years ago and someone in the class asked why concentrators weren't used to focus sunlight on the pv panels. The instructor said that the thermal characteristic of solar cells gives higher resistance at higher temperatures, and you really want to do everything you can during the design phase to keep the array cool.
...
I think this would be a low efficiency pv with some solar thermal mixed in. Since they specifically mention their cooling system extends cell life, they are probably (rightly) worried that the higher temp will degrade the cells. The economics of pv depends on the panels lasting 30 years, if you have to disassemble an array with a bunch of lenses on top every 5 years and replace the modules, it's not going to be cheap. [pv cost/hr = (equipment + installation)/ (# of hours the system will work) + maintenance] (it works like an oil well, you spend $20k to build a system, it give you 5 hours of full power per day for 30 years]. eg, for a 2KW pv that cost $20k over 30 years = $.18/kWh.

of course I hope their product is perfect and I can stick a 4 kw plant in my backyard in 5 years for $30k.

Jim Harris wrote:

Again why do we want to fix what isn't broken?

You're misinterpreting my point. I'm not saying that capitalism itself is in any way broken. I'm not saying, oil is at $125, so let's burn our economics books and rise up an make the proletarian revolution. The laws of supply and demand are sound, so yes, from a distance an economist could say that we shouldn't fix what it isn't broken. However, those laws do require that the agents within the system are willing to fix what is broken for them. Even if the world economy continues be a sound laboratory of capitalist economics, peak oil clearly is a problem that oil consumers should want to fix.

At the level of generalities, you've said that economic agents will sooner or later fix all of their problems. That's fine. But at the level of specifics, Rand is clearly saying the opposite. He is wishing and predicting that peak oil is just a blip in supply and technology. Oil consumers don't need to "worry" --- meaning that they don't need to change their indulgences --- because producers and inventors will solve the problem all by themselves. My point is that rational oil consumers shouldn't listen to this wishful thinking.

Another point is the difference between expenses and hedging. Of course, all actors respond to both, but the fact is that large actors can hedge more than small ones. Especially governments. Hurricane Katrina is a case in point. The city government of New Orleans, the Louisiana state government, and the Army Corps of Engineers were the only actors positioned to hedge New Orleans against big hurricanes. They fell short.

Clearly zoning and transportation policies have left America poorly hedged against high oil prices. We would have been in a better position if we had not already burned 200 billion barrels of our own oil. Will our government transportation departments be rational actors in the face of high oil prices? If they fatuously declare that the market will fix it, or if they expect some latter-day Edison to fix it, no they won't.

Anonymous wrote:

http://www.industryweek.com/ReadArticle.aspx?ArticleID=14932

This says $2 per watt for Gallium telluride IIRC.

Mike Puckett wrote:

^Me

Mike Puckett wrote:

Make that Cadnium Telluride.

Fletcher Christian wrote:

Hmmm... The problem given is how to extract energy from sunlight in otherwise useless deserts, cheaply in terms of both initial investment and ongoing maintenance. Have I got this right?

Solar panels are expensive, and only work 50% of the time on average and at less than 100% efficiency most of the time even when they are working, unless one spends even more money on steerable panels. They also cost a lot of money to maintain, in a desert - there's a lot of area, and deserts are dusty, so they need cleaning if nothing else. They also aren't all that efficient at the moment.

Right, what do we do about all that? Well, there is a cheap process with 5% conversion efficiency and with energy storage built in. That, of course, is photosynthesis. Of course, deserts are deserts because nothing will grow without adding massive amounts of water, but it is possible to use photosynthesis without this problem, and in a closed-loop process - simply by growing a suitable unicellular plant (probably one of the blue-green algae) in thin, flexible, transparent tubing and recycling the water and nutrients.

It would go like this. Grow your algae, and in a continuous process skim off as much as possible consistent with keeping the algae density in the tubing high enough. Break down the algae, separate out the oil (very high percentage in some algae), dry off the rest - save the water vapour, condense it by some method (either wait until night, or condense it below ground where it's cooler, or something). Return the water to the unit. Burn off the solid matter left (perhaps getting some power out of it, to run the machinery and maybe even for export) and return the minerals thus released to the apparatus as well. Done right this could be a continuous process with minimal inputs, and an output usable for energy, and low maintenance cost. The fact that the output is a fuel rather than electricity gives a reserve for when it's dark.

Of course, all this mucking about makes the process even less efficient than the photosynthesis powering it, but who cares? The input power is free. What matters is installation and maintenance cost - and I have never seen a study on the economics of such a system. Can anyone point me at one?

One last thing; At some cost in setup, it would be possible to do the same as could be done with an SPS rectenna - make the area underneath all this tubing usable for something else, simply by not jamming them together. Do it right, and people might even like sitting in its shade.

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This page contains a single entry by Rand Simberg published on May 9, 2008 8:05 AM.

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