Solar Tower, someday...

February 24, 2005 9:24 PM

The kilometer-high Solar Towerto be built in Australian outback (previous post) has finally purchased a site, and construction may be finished in 2009. Other towers may be built in China and the US.
posted by homunculus (40 comments total)

the Australian outback.
posted by homunculus at 9:25 PM on February 24, 2005

They could make a shitload of money by painting the bottom a different color and going for a Marlboro endorsement.
posted by keswick at 9:32 PM on February 24, 2005

Buying the site is one thing, but getting the money to build it is another... and from the sound of the articles, they're still working on that.
posted by crazy finger at 9:53 PM on February 24, 2005

I want to see that happen. I also want to see one of those sci-fi space elevator things. And a moving sidewalk, an aircar, and a computerized self-tending apartment, while they're at it. O will the future ever get here?

Keswick, you are one sick puppy. I say they should make it look like a great big doggie dildo.
posted by davy at 9:58 PM on February 24, 2005

Buying the site is one thing, but getting the money to build it is another...

Between the recent movements in the price of oil and impending interest rate rises, I don't think they'd have too much trouble organising an ASX placement.

*crosses fingers*
posted by pompomtom at 9:59 PM on February 24, 2005

By the way, why does the phrase "flying lessons" occur to me about that proposed kilometre-high erection?
posted by davy at 10:00 PM on February 24, 2005

Please, please, please happen.
posted by Mr_Zero at 10:02 PM on February 24, 2005

I also want to see one of those sci-fi space elevator things. And a moving sidewalk

Never been to the airport, eh?
posted by berek at 10:05 PM on February 24, 2005

First reaction: "Mildura's hardly the outback".
Upon googling: "Hey, they've created this bullshit tourist destination."

It's climate, often described as Mediterranean, is perfect for all pastimes.

Bwahaha!
posted by Wolof at 10:16 PM on February 24, 2005

This looks brill! More pics [1] [2]
posted by tellurian at 10:35 PM on February 24, 2005

I think there's a test tower somewhere in the Negev desert - when I was in Israel in 2000, we were given a presentation on this. At the time, the idea of a 1000m tower struck me as being far-fetched. I'm impressed, and glad, to hear that progess is being made.
posted by kickingtheground at 10:50 PM on February 24, 2005

The scale of this project doesn't suprise me, but what does suprise me was that the design for the new development on the WTC site could be so unimpressive in it's scale.
posted by VP_Admin at 11:22 PM on February 24, 2005

PS -- I can't wait to see the tower up. Fantastic stuff.
posted by Wolof at 11:26 PM on February 24, 2005

All I know is they're not gonna like this in Toronto. Been calling this thing the World's Tallest Freestanding Structure for 30 years.
posted by scheptech at 11:34 PM on February 24, 2005

This is great stuff, I love the innovation and brilliant elegance of the concept. It reads like something from SimCity and I want to see it built as well.
posted by fenriq at 12:00 AM on February 25, 2005

Freestanding, scheptech... this tower generator dealie appears to be supported by wires. The CN Tower stands on its own.
posted by onshi at 12:35 AM on February 25, 2005

This is very cool, but 200,000 homes doesn't seem like very much. It can power a small city. That ain't much compared to the size of the thing. Or am I reading this wrong?
posted by zardoz at 3:55 AM on February 25, 2005

Couple of dodgy claims in that Wired report.

The solar tower will run 24/7 not because of "banks of solar cells", but because the ground underneath the canopy stores heat, and the bottom of the chimney will therefore always be warmer than the top; the convection current will never stop. By varying the amount of water stored under the canopy, Enviromission will be able to tweak the heat storage characteristics to best match electricity demand.

Also, I sincerely hope that the US government is not "pinning hopes on hydrogen as a new energy source". Hydrogen is going to be a very useful zero-greenhouse automotive fuel, but an energy source? Nope.

Pompoptom: Enviromission's ASX code is EVM (I bought 20000 shares at 20c, they're currently trading around 30c - woo hoo)

kickingtheground: I think you'll find that what's under development in Israel is a cool-air convection tower, which runs on cool air sinking down a tube instead of hot air rising up one. As far as I know, there has been no successful pilot project yet.

onshi: the tower generator dealie is to be a great big freestanding concrete tube. The only wires in the design are to hold up the canopy, way down near ground level. There will be steel "spokes" across the inside of the tube in a couple places to keep it rigid, but no external guys. Suffer bigtime, Toronto :)

zardoz: If you work out the amount of solar power hitting the collector, and compare that to the amount of electrical power you get out of the generators, the conversion efficiency looks absolutely dismal - it's actually under 1%. On the other hand, most of the land under the collector can be used for growing crops (it is, after all, nothing but a great big greenhouse), the materials used to build it don't cost insane amounts of energy to make (it's supposed to pay back its own embedded energy of construction in about two and a half years) and the running costs are ridiculously low compared to any other way to generate that much power.

Australia is actually a really good place to build these things. We have lots of sun and endless stretches of great flat fsck-all to play with. It's going to be a bloody amazing view off the top of this thing, and as a small shareholder I hope to persuade the company to put a hang-glider launch platform inside the tube :)
posted by flabdablet at 4:49 AM on February 25, 2005

Handy comparison of this thing with the Freedom Tower (new WTC) and CN Tower (in Toronto, Canada).
posted by Plutor at 5:20 AM on February 25, 2005

I can't imagine this thing being anywhere near a reasonably sized load center (city), so what's it going to cost to permit and build the power line needed to transmit the energy for a long distance? Oh yeah, and people hate those things.
posted by jasn at 5:46 AM on February 25, 2005

I just hope we can build these fast enough to save the world. Hell, there's enough square footage over the ocean that we could build thousands of these floating out at sea and provide all the energy the world needs. In fact, over the ocean, these could be used for desalinization and extraction of hydrogen.
posted by PigAlien at 6:05 AM on February 25, 2005

More power to them.
This sounds like a great idea.
posted by Busithoth at 6:14 AM on February 25, 2005

Hmmm. Call me skeptical.

The article estimates the cost of the plant would be at least 500 mil$, but only generate 200 MW. That's a capital cost of over $2500 / kW, double what an equivalent gas, or even nuclear plant would cost. Investors hate long-term returns, so I'd be very surprised if Enviromission can raise enough capital.
posted by Popular Ethics at 7:22 AM on February 25, 2005

jasn: I can't imagine this thing being anywhere near a reasonably sized load center (city), so what's it going to cost to permit and build the power line needed to transmit the energy for a long distance? Oh yeah, and people hate those things.

Hydroelectric dams are not usually close to the power sink (heck BC sells power to California) and people hate not being able to turn on their A/Cs a lot more than they hate power lines. Power lines aren't always the best solution anyways. If you've got a source of water (even salt water) handy you can convert the electricity into Hydrogen and then pipeline it or transport it by rail.

I hope this is successful. Constant, essentially pollution free, power. It's like it's raining money and all you need to do is build a bucket.

One of the interesting to me future locations for additonal tower power plants would be the middle east. The countries presently have a lot of capital funding available; they are land connected to Europe and Asia; lots of high temperartures and sunshine; and they have a well developed shipping infrastructure if they decide to convert the electricity into hydrogen.

Course most areas shouldn't be importing electricity, they should be building these towers themselves. You don't actually need a desert to make these things work it just makes the land cheaper if it's not arable.

a capital cost of over $2500 / kW, double what an equivalent gas, or even nuclear plant would cost.
This is within spitting distance of US hydro project's average of $2000 per kWh which is a much better comparison. Hydro plants can cost almost $5000 per kWh. Keep in mind that a gas or nuke plant has a cost per unit which will only be going up both because of peak oil and Kyoto.
posted by Mitheral at 7:49 AM on February 25, 2005

This is within spitting distance of US hydro project's average of $2000 per kWh which is a much better comparison. Hydro plants can cost almost $5000 per kWh.
Per kW, not kWh I hope (Seeing as how my utility sells electricity for 4c / kWh). Good point though. It's about even with wind turbines too, however the latter is available in smaller, easier to buy doses.

Keep in mind that a gas or nuke plant has a cost per unit which will only be going up both because of peak oil and Kyoto.
The capital cost figure I quoted does not include operating, fuel or pollution control costs, so that won't change. However I grant that their return on investment is getting longer as their profit margins get smaller. I still think the solar tower will take so much longer to pay for itself (despite its obvious environmental benefits) that the market won't consider it viable.
posted by Popular Ethics at 8:12 AM on February 25, 2005

Too bad there aren't non-profit, taxpayer-funded entities willing to step in and provide a necessary service where the market won't.
posted by trondant at 8:44 AM on February 25, 2005

The point that seems to be missed when talking about clean power generated in the middle of nowhere is the value of Renewable Energy Certificate System (RECS). RECS are currently being traded on the open market to help promote development of renewable power sources.

This means that if a supplier in the U.S. needs to meet a renewable requirement for part of their portfolio in a market, they can trade "dirty" RECS (produced by coal or oil) for "clean" RECS produced in, let's say the outback of Australia. Currently,

There are also different flavor of clean RECS. You can by hydro, wind, or solar.
posted by SteveInMaine at 9:40 AM on February 25, 2005

Eviromission got off on the wrong foot by spamming me a couple of years ago. The project looks like it would use a lot of construction materials (and thus, lots of oil) for relatively little yield. As others have said, it needs to be somewhere hot, which is basically where people (and their electrical needs) aren't.

PigAlien, I doubt this would work offshore. The sea tends to be fairly cool, and thus there wouldn't be the necessary temperature differential to make this work. Plus, making a kilometre-high offshore floating pipe would be hard.

Mitheral, your "raining money" statement is one of the reasons people fall for physically impossible alternative energy projects. If I had $1 for every new gee-whiz new design of small wind turbine that claimed efficiency over the Betz Limit, I could be adequately remunerated.

I wonder what power output you'd get if you took the project area -- about 100km^2 -- and covered it with solar photovoltaics? There's just something off about Eviromission's statements that I can't quite identify. It's like my bogometer is picking up background bogosity readings, but it can't quite locate the source.

There are better and cheaper ways of harnessing sustainable energy than this. Coastal windfarms spring to mind, but then, since I am a windfarm designer, they tend to rather a lot.
posted by scruss at 9:43 AM on February 25, 2005

Wow. Coolest tower ever.

I'd really love to see these things get built all over our country. We have plenty of space for it, and it seems like once the thing's built, it's going to have a pretty damn low operating cost. Assuming that, with regular maintenance, they can keep one of these running indefinitely, it seems like it'll end up being a pretty economically viable solution.
posted by salad spork at 9:46 AM on February 25, 2005

I wonder what power output you'd get if you took the project area -- about 100km^2 -- and covered it with solar photovoltaics?
The efficiency of photovoltaics is around 30% now. As mentioned earlier, the tower uses less than 1%. So a PV array this size would generate 30 times more electricity. That said, solar cells have an even greater capital cost / unit power, so it would cost 60 times as much - about 12 billion!

There are better and cheaper ways of harnessing sustainable energy than this. Coastal windfarms spring to mind Windfarms can spend as little as 5% of their operating life generating their rated capacity. That's why their costs range from an affordable $800 / kW, to a money-loosing $3500 / kW.

That's why this project is getting some attention - it's almost (but not quite) commercially feasable.
posted by Popular Ethics at 9:57 AM on February 25, 2005

The expression "pipe dream" came immediately to my mind. After the time that my brother spent as a mechanic maintaining equipment at the Tehachapi CA wind farm I've become sceptical of the return over time for some of these applications of green energy technology. I'll wait to see the five year and ten year reports after the big jump is made from a 600' pilot project that worked an average of 8 hours a day to a 3000' fully operational unit.
posted by X4ster at 10:38 AM on February 25, 2005

Photovolatics also need cleaning to get their rated output and as they age there output is reduced (by up to 50% over 20 years). This isn't a problem in small scale home generation as you just throw up another array but it doesn't scale well. One of the advantages of the tower is the heavy lifting maintenance is all centralized. After all the actual generators are just scruss' coastal generators turned 90 degrees.

Though caution is always warranted in alternative energy producing this seems to be a pretty straight forward application of existing technology.

We already build tall reinforced concrete buildings and can cost them. We already build large green houses and know how much they cost per acre. We already build wind turbines and know how much they cost. We already build functional solar chimneys powered by green houses in residential construction. A proof of concept has already been built and tested in Spain. Short of some unforeseen engineer problem ala the twin narrows bridge this seems fairly straight forward.

One problem with commercial wind and tidal farms (and hydroelectric for that matter) is they require a fairly narrow range of local conditions to be viable. And those locations are often in strong NIMBY locations at least in the US. Look at all the problems they are having in Natucket Sound where the locals can barely see the turbines yet are successfully delaying the project. A project which would be a slam dunk in say the Netherlands. Solar towers can be placed in fly over country and desert areas far from moneyed persons with pull.
posted by Mitheral at 10:49 AM on February 25, 2005

It did occur to me that maybe this project could provide knowledge that would make future power plants more powerful and efficient. On the other hand, if it's a privately owned system, then there may not be as much incentive to share the info.
posted by rolypolyman at 11:10 AM on February 25, 2005

I don't see anything about plans for a wine cellar at the top, so Toronto's safe for now.
posted by DrJohnEvans at 11:34 AM on February 25, 2005

Thanks for the latest news, homunculus. I've been following this development for awhile, because it is to my mind one of the most hopeful things I've heard about in a very long time.

I have a few queries for the skeptics in this thread (particularly the ones who question the profitability of the project):

- Did a global fleet of single-passenger, self-propelled vehicles running internal combustion engines that burned fossil fuels look cost-efficient in 1900?

- Would you be this skeptical of, say, a new super-sized nuclear plant? Is nuclear power profitable? Is it efficient?

- Might there be reasons other than economic ones to develop new energy technologies even if they are not profitable in the short-term?
posted by gompa at 11:49 AM on February 25, 2005

Might there be reasons other than economic ones to develop new energy technologies even if they are not profitable in the short-term?

No, with this caveat:
Building a powerplant this size is a HUGE cost. The only players capbable of coming up with the dough is the market, and the government. As much as I want my government to be fostering green-power, I don't want them plunging the country into debt to do it. A more practical approach is to raise taxes on fuel and emissions (carbon tax) so that the cost of OTHER technologies rises to the point where the market chooses green technologies instead. The end result is we all pay more for electricity, but you can't have your cake and bake it too.
posted by Popular Ethics at 12:38 PM on February 25, 2005

Perhaps to really gain competitive per Kw price advantage on this technology, they could incorporate horizontal wind generators either on top or at various points on the exterior of the tower. From watching the video of the test tower in Spain, it appeared that there was quite a bit of local wind that could be harnessed in this way. And since there's already a nice tall structure on which to place the windmill(s), you're really using space efficiently. That, and power stepping and/or conversion can be accomplished with 1 module for all the generators on board.

I think the only major engineering hurdle would be dealing with torque or wind loads caused by extremely high winds. There are ways of dealing with this problem, such as rotors that can adjust for wind speed or close flat altogether, rotor brakes, etc.

Anyone with engineering knowledge care to comment on this?
posted by pjsunray at 1:08 PM on February 25, 2005

Windfarms can spend as little as 5% of their operating life generating their rated capacity

Popular Ethics, while you might not see rated power all the time, a wind farm will typically see a 30% capacity factor. Unlike most forms of generation, wind turbines have to handle a huge variation in power output at unexpected times. Rated power is typically 125 times that of cut-in power, and the wind can throw you anything within that range at any time.

Mitheral, it's not worth putting such a small project so far away from people. One might expect to pay around $1m/km for a power line for this size of project. If you're more than a very few tens of kilometres from civilization, the line costs will be significant.

I also suspect that you'd need hot desert for this to work, so your locations are more limited than most other forms of renewable energy.
posted by scruss at 1:13 PM on February 25, 2005

jasn: one of the reasons for picking the Tapio Station site is that it has good access to the existing grid; there shouldn't be much extra transmission line needed.

PigAlien: we may have trouble figuring out how to float a 1km concrete tower. Engineering the tower and canopy to resist the effects of waves and currents would be, I think, expensive. Also, because the ocean surface is water and does have waves and currents, the air above it wouldn't heat up as well as the air above land, making the solar chimney's already dismal conversion efficiency even worse. I really think that dry land is the best place to build these things.

On the other hand, wave generators work a lot better on the ocean than they do on dry land :)

Popular Ethics: yes, the initial capital cost is higher than for a thermal plant of equivalent output. But the running and maintenance costs are much lower; fuel and waste disposal costs are zero, you don't need a large and highly specialized staff to run it (all you have to do is keep the canopy moderately clean and service the turbines every once in a while). Plus, you get additional income streams from tourism (the view over the great flat f-all from 1km up will be breathtaking), advertising rights (that puppy is gonna be visible from a long way away), and agriculture under the canopy (frost free - should allow production all year round). Speaking as an actual, paid-up investor - I love it!

scruss: the tower is supposed to pay back its embedded energy cost in two and a half years. Concrete, steel, glass and plastic film are a hell of a lot cleaner to make than silicon PV cells; also, a PV cell array would stop generating power at night. By the way, your project area estimate is too high (a circle of 3.5km radius has an area of about 40km², not 100).

Also: how many kilometres of scenic coastline do you have to modify to make a wind farm with a guaranteed baseload capacity of 80MW continuous, 200MW peak, with peak output inherently matched to peak demand? A single, simple, vertical chimney visible from a great distance will, I think, be much less visually intrusive than hundreds of identical turbines and their associated transmission lines. No bird-strike issues either.

Australia has vast amounts of flat, arid land - some of it with great big intercity grid connections already striding over it. This project is a good match for our conditions.

X4ster: the tower will have 32 turbines (many many fewer than a wind farm of equivalent capacity, but enough that even if several fail at the same time, the power output won't dip much). The turbine design will be simpler, since they'll be fixed in place instead of needing to track the wind, and all the machinery will be more accessible (fixed inside a structure at more-or-less ground level, not stuck up on a tall pole). The maintenance costs should be quite reasonable.

pjsunray: sticking extra generators to the outside of the tower strikes me as unlikely to be cost-effective. If Enviromission wanted to boost the available power output by X%, all they'd have to do is add X% more plastic film around the outside of the canopy. Attempting to maximize the energy conversion efficiency in a design where that kind of efficiency is obviously not the primary concern seems like a silly waste of engineering, to me; much better to maximize power output per dollar spent.
posted by flabdablet at 6:28 PM on February 25, 2005

While it has been mentioned several times already in this thread that this project will be zero-emissions, just so that no-one goes away with the idea that this is we're getting something for nothing, it should be noted that this type of power plant will, by definition, still contribute to global warming, by simple virtue of the fact that it is a greenhouse and will therefore reduce the Earth's albedo by a tiny degree.

Personally, I am growing convinced that "green nuclear power" is the only way forward in the long run - although even the greenest nuclear plant still generates a vast amount of waste heat that has to go somewhere (I mention that just so's no-one thinks I'm totally ghosting the solar chimney idea)

Wired carried a surprisingly thoughtful article on modular pebble-bed (nuclear) reactors in the December '04 issue; if we can get beyond a knee-jerk fear of nuclear power and commit to responsible management of the waste products, perhaps that hydrogen economy might just work.
posted by kcds at 3:34 PM on February 28, 2005