Slashdot Mirror
Solar Power Put to Good Use
Current Shunts writes "Teams from all over the U.S. and Canada will be competing this summer over a 2,500 mile course from Austin, Texas in the United States to Calgary Alberta Canada for the 2005 North American Solar Challenge. The purpose of this event is to promote renewable energy technologies, integrate science and engineering disciplines, and give competitors an opportunity to showcase their technical and creative abilities." At the same time, zestyalbino writes "Construction on the world's largest solar tower [RMIT] may begin next year in Mildura, Australia. In a nutshell, "An ever present large mass of air under an expansive transparent collector (seven kilometres in diameter) is heated by solar radiation (greenhouse effect) providing a continuous flow of hot air to drive electricity generating turbines located around the base of the one-kilometre tall central tower." There's also an article on Wired."
Let's just ignore the chemical costs of making solar collectors.
as opposed to all those evil uses for solar power?
Solar Power Put to Good Use
Excellent! I was getting tired of all the bad uses it is put to.
What? I thought the purpose of this event was for the various Engg departments at all the competing schools to have a general good time, fostered by healthy rivalry and no doubt a few unspeakable antics along the way! That is why we have these competitions isn't it? I mean, who really cares about solar power? Especially in Calgary, the Fossil Fuel Capital of Canada.
Hold on, before you mod this post (+5: flamebait) let me continue.
I'm in the department of Electrical and Computer Engineering at the University of Calgary, and although I'm not actually on the Solar Car Team (yet... they're recruiting like mad), they did steal our study room to use for their club room. So it's almost like I'm a part of it... sort of. In fact, there's a whole bunch of leftover crap from their wooden prototype crowding the hallways here right now.
But ya, all joking aside, I think it's a really cool challenge and we here at the UofC look forward to competing alongside other great academic institutions. (And having a good time besides! I tell you, if UofC wins this thing, there's gonna be a party in Calgary the likes of which we haven't seen since our precious Flames almost won the Stanley Cup....)
Ok, now feel free to mod this (+5: flamebait) for shamelessly bringing up the NHL.. or lack thereof (sigh)
My father invented and patented this idea; the US patent, granted in 1981, was originally filed in 1975. He never got a dime out of it, and the patents, in Canada, Australia, Israel, and the US, have all expired. I guess he was ahead of his time. More information here.
Jesse: "I'm still fighting for the earth. I even got 'em to install a solar-powered electric chair."
Snake: [in the solar electric chair] "Dude, we've been here all morning! Could you at least remoisten my head sponge?"
http://www.snpp.com/episodes/CABF01
Near where I live there are dozens of fatalities per year involving gas guzzling vehicles. They may be unsafe on highways!
The article you reference shows it was a loose brake line; how is this specific to solar technology?
-1 troll.
"Orthodoxy means not thinking--not needing to think. Orthodoxy is unconsciousness." --Eric Blair
People perform and achieve so much more if you give them a challenge. These races are the breeding grounds for new technology that can eventually find its way into future cars.
What I would like to see is an electric Formula 1 type competition, I would bet that it would only be a few years before we would have electric cars with performance and range to match current Formula 1 cars. With developments in electric motors and battery technology that can then flow on into domestic cars, just like disc brakes, seat belts, crumple zones, fuel injection, and the list goes on...
One cool thing about the solar chimny though is that apparently it can generate power 24hrs/day, unlike wind that fluctuates. Basically the solar chimny generates electricity from the same type of turbine that a wind turbines use.
So I'm not sure these guys are really promoting anything. I strongly suspect their races are having the exact opposite effect, in fact: convincing people that solar technology is nowhere near ready for prime-time. Instead of showcasing stuff solar tech can do that nothing else can, they're showcasing the stuff it does really, really poorly.
As an academic project, I think this is great. I'd love to be involved in it and I'm sure I'd learn a lot just from following it closely. But as PR? Not even close.
Solar Tower my ass.
Where's the rollercoaster built around it with the bungy jumpers streaming to and fro? Where the Rush Limbaugh Ride where you can ride a vent of hot air to the top while sucking down pain killers? Where's the naked acrobat midget dancers? I mean, this is Austraila. Can't we at least put a huge magnifying glass at the top to fry tourists like ants? No? And where's the fucking beer?
Every year we're subjected to media coverage of a number of these solar-powered races, and with each one, it gets less and less interesting.
It's not a big surprise that you can take thousands of dollars worth of carbon fiber and build an extremely light and impractically fragile vehicle with a design lifespan of a few dozen hours. No real science is being done in these races, just incremental advancements in the application of computational fluid dynamics and power control circuitry. Reduce the drag coefficient by 0.5% over last year's design, cut the weight by two kilograms... it's a complete waste of time.
This will *NEVER* result in a practical vehicle, for the simple reason that the theoretical maximum power you can get out of solar cells is on the order of 1000W/m^2. These solar races are not baby steps toward a future in which we'll all be driving solar cars, they are just a dicksizing event between university engineering departments.
Even as such, they're a waste - there are far more impressive things upon which a group of talented young engineers could focus their efforts.
Nix absolutably seriousness.
Archimedes supposedly set fire to the Roman Navy using an arrangement of mirrors.
And you probably wouldn't want to have this guy as a neighbour, as he used reflected light from 100 mirrors to "cut" the tops off several trees.
many many months now, and i have scanned it thoroughly for construction dates, and its closer to 2~3 years until the design is even finalised, so 1 year sounds pretty optimistic to me. "worlds largest solar tower"? its will also be the worlds first non-prototype solar tower, 1km tall. i'll be travelling down there from Sydney to monitor its progress. -5 Troll modifier, well at least i got my opinion out :P
Leon O. Billig, in a fact article in _Analog_ titled "Defeating the son of Andrew" (11 years ago this month), proposed convection towers on the order of ten times as tall. I recommend this article to everyone as a mind-stretching exercise.
Time is Nature's way of keeping everything from happening at once... the bitch.
"At temperatures up to 70 C beneath the greenhouse, nothing is going to grow there and soil moisture will be lost rapidly."
.au, at least). Salt is carried to the surface by the water table rising. Anything that causes a lowering of the water table prevents further salination, so accellerated surface evaporation is as good as revegitation. Again, this has all been taken into account.
The highest temperatures will be in the center of the array, and closest to the ceiling. The temerature at ground level and around the rim will be lower, thanks to the very convective effect that makes the whole proposition feasible, but by how much will depend on the ceiling height. Remember thermal gradients; it may not be possible to use the entire area, but a good portion of it will never come close to70 C. I have to point out that growing plants under it is actually part of the proposal, it isn't my idea. If you don't think it's possible, tell the people planning it, I'm sure they'll appreciate the advice.
"It may be possible to use this land to extract salts for industrial use"
Not really, it's common sodium chloride, and much more readily available in commercially attractive deposits elsewhere; desalination plants along the nearby Murray River, for example.
"From this I gather that, as a first approximation, energy expended to evaporate water will be lost"
Two points: (1) Mildura receives little rainfall (irrigation is vital), so surface water isn't as much of an issue as you might think, and (2) this has probably been included in the effciency calculations.
"I doubt that a large expanse of even more highly salinated land is going to contribute much to the local environment."
You don't understand the mechanism behind land salination (in
Blank until
Sure, there are other costs...but everything has other costs. Can you put a price on the fact that coal spits out 100 times the amount of radioactive material into the air than a similar sized nuclear plant? How do you even clean that up? Also, everything in the energy sector is subsidized. No nuclear power station has EVER broken even in North America...but still our energy bills are cheap...why? Because our energy is subsidized. Maybe you don't need a subsidy to build a coal power plant, but your tax dollars sure do go to paying for environmental damages, health damages and other things associated with the coal power plant.
...but you're only looking at the inital costs, not total cost of operation. A nuclear reactor is far more expensive to run and maintain, contains more moving and pressurized parts requiring higher standards of engineering expertise, reactors produce nuclear waste which is expensive to transport and store (and the waste from the tiny, 45 year old research reactor we have in Sydney is politically volatile enough, thank you), and at the end of the working life there's still the problem of decommissioning with the associated clean-up and disposal costs.
By comparison, this takes a lot of land (but considering Australia is a largely arid continent with a population not much more than 20 million mostly living on the coastal fringe, appropriate land isn't hard to come by), but requires relatively little maintenance, no expensive and hazardous fuel, little to no full-time supervision, and can be repaired by glaziers rather than expensive nuclear technicians; an entire installation could be run by a staff you could count on one hand. It also wouldn't require the same degree of security, which is another saving.
Oh, and $1,300 per kW = $1.3 million per MW...slightly more than 50% of what this tower is projected to cost (hardly WAY out of line, nice try at slewing the figures though), so with the overall savings in operational and maintenance costs over an average lifespan of (conservatively) 30 years, the solar tower *still* comes out in front.
Blank until