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New Solar Panel Design Traps More Light
GoSun wrote in with an article about new solar panels that opens, "Sunlight has never really caught fire as a power source, mostly because generating electricity with solar cells is more expensive and less efficient than some conventional sources.
But a new solar panel unveiled this month by the Georgia Tech Research Institute hopes to brighten the future of the energy source." The new panels are able to produce sixty times the current of traditional models.
you don't want it bright, if it reflects light that's unused energy!
you want a dim future
It's good to know that solar power is really getting off it's feet.
60 times the current, at 1/60th of the voltage. They're working hard to achieve the next milestone which is 100 times the current (at 1/100th voltage) before Xmas ... in space.
Sunlight has never really caught fire as a power source
Well, I always saw that as a good thing, I don't know about everyone else here...
This is non-news. Multi-layered cells have been talked about forever, and haven't they all previously run into similar issues?
File under: Federal government grants.
Hey, I paid for all the other ones, why not this one.
"...produce sixty times the current of traditional models" BS!!
Current solar cells are ~20% efficient... you can't do better then 100% obviously.
If you can get low $/watts with low efficiency that would be OK. Tile your house with the stuff, use it as the external covering for buildings.
That is one of the major problems with PV showcases like the Australian solar race. they push efficiency more than $/watts which is my the winning cars cost hundreds of thousands of dollars.
Engineering is the art of compromise.
The new panels are able to produce sixty times the current of traditional models.
Yeah, right around the time that AI finally works, fusion power becomes practical, and pot is legalized.
Recall that most solar cells on the market acquire 10-20% of the energy that falls on them. Electrically, power is current times voltage. So this is a bogus claim. There's no point to claiming that the solar cell gets "60 times the current" while ignoring voltage (which dropped by an unspecified amount), and ignoring that there's only a theoretical factor of 5 to 10 possible improvement in power over current solar cells.
Yawn. Posting about how a supposed innovation is actually several years old has been done before. Didn't we just read a post titled *yawn* yesterday?
It's power that matters, not current.
The best solar cells today get about 13 watts / square foot. The toatl power available on a sunny day with near perpendicular light is 130-140 watts. So efficiency is near 10%. The best a new design can do is about 10-11 fold increase, not 60.
I've heard that the energy cost of making the panels is greater than the amount of power they generate in their lifetime. Don't know if that's true though, but it takes energy to make the panels, and they do wear out / break.
Hi! I make Firefox Plug-ins. Check 'em out @ https://addons.mozilla.org/en-US/firefox/addon/youtube-mp3-podcaster/
Besides the bad pun... you obviously have never used magnifying glasses on poor helpless insects...
There was a Monty Python episode where they were comparing penguin brains to human brains. They found that if the penguin were scaled up to human size, its brain was still smaller than a human brain. But -- and this is the important part -- it's larger than it was before!
the best solution to our energy problem in the long run would be some source that doesn't deplete anything on our planet. That pretty much leaves solar, wind, geothermal and tidal. And it could probably be argued that geothermal would cool the earth's core faster.
What I absolutely do not want, however, is the same greedy bastards that are raping us now for our energy to control the development of future energy. Think about it. If they have a choice of giving us near free energy or continuing to corn-hole us, which do you think they'll choose?
The race isn't always to the swift... but that's the way to bet!
In an ideal conversion you can get about 1KW per square meter when the sun is directly overhead.
Call me when you get something that is more than 0.5KW/m^2 and that doesn't rival titanium on the "nasty to manufacture" scale.
Until then it's all just blah blah blah trying to make your University look good in the press.
I'm tempted to say "Cripes, This Again," because it comes up in almost every discussion about solar cells.
Instead I'll say: That may have been true once, but it isn't any more. It will become less and less true with time, as learning economies and economies of scale come into effect.
The op article was vague and didn't have the pretty picture the one below has:
o lar.htm
http://gtresearchnews.gatech.edu/newsrelease/3d-s
If we had so many wind turbines that we were collecting enough power to run the world, would that not have some effect on the global wind patterns?
Also solar power cools the Earth's surface. Solar farms are envisioned as acres and acres of panels in the desert. That would turn a very hot spot into a very cold spot, changing the currents there, and thus affecting overall temperature distribution (ie, the wind).
Same sort of thing goes for tidal energy. If you collect enough, you are going to affect life in the ocean. There just ain't no free ride.
But there are two viable solutions:
Solar panels that opens? Do they use pulleys or motors? Isn't this kind of obvious? Prior art anyone?
Take the cheese to sickbay, the doctor should see it as soon as possible - B'Elanna Torres, "Learning Curve"
MrCreosote Meow!Thump!Meow!Thump!Meow!Thump! "You're right! There isn't enough room to swing a cat in here!"
But it doesn't matter to me that some hydro-electric plant far from my house is making power at $0.02 per kWh, what matters to my economic reality is that my local power company charges just over $0.08 for the first dozen kWh delivered each day and then has a sliding scale that goes up to $0.36 kWh for increased amounts of power.
Before I installed solar panels a high percentage of my power was costing me that top rate. So the relevent economic calculation for me is the cost to install my panels divided by the expected number of kWh that they will generate across their lifetime. This number comes out at about $0.16 per kWh. So I'm better than breaking even now, and assuming that energy prices continue to rise, I'll do even better in years to come.
The final kicker in the equation is that I've switched to a time-of-use tariff so across the summer the power company will credit me with $0.209 for excess power that I generate in peak hours (between 1pm and 7pm), and $0.112 for partial-peak (10am-1pm + 7pm-9pm).
If I'd taken the capital that I used to install the panels and invested it instead, I'd have to maintain a >19% annual pre-tax rate of return to beat the panels. Possible, but extremely unlikely (especially with my stock-picking track record!).
It doesn't make any difference how rough the surface is. Will a rough surface make the daily average shadow of the panel any bigger? If not there is no more energy to collect.
TFA doesn't claim increase in power, just current. Anybody who paid attention in middle school science knows Power=Voltage*Current.
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
Why isn't this tagged "itsatrap"???
Agent K: A *person* is smart. People are dumb, stupid, panicky animals, and you know it.
Ok, I'm a solar cell expert. I've been buying and selling solar cells/panels for years and I also construct panels with 0.5V 2 to 6A single-crystal cells... Now, take it from me, it is IMPOSSIBLE to construct a solar cell that is 60 times more efficient... like these other people are saying, the voltage would have to be considerablly less for the current to be 60X higher... the reason being is that THERE ISN'T EVEN THAT MUCH LIGHT COMING FROM THE SUN!!!!!! There are already cells out there that surpass 35% to 40% efficiency so DOUBLE would be an enormous step, but even 4X the efficieny is impossible.
Sorry guys.
Now all we need is something that can trap more girls and well be set!
"When life gives you lemons, don't make lemonade. Make life take the lemons back!" -- Cave Johnson
It's like a third grader's book report... Why don't we just get the water from the well... from GTRI's site
Maybe a power engineer can answer this... the obvious way to build a solar power plant is to take a whole slew of lenses and focus them on a water tank, and then turn a turbine. Given that heat -> power is a fairly mature technology, wouldn't that be more efficient than solar cells?
Sometimes it's best to just let stupid people be stupid.
Sup, homes?
What?
The tracking motors etc for the mirrors are the deal breaker.
The only number that matters is $/watt. If they're cheap but inefficient we just cover the whole roof. If we run out of roof there is plenty of space in the western US.
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
Man, I wish we'd spent that Iraq War $TRILLION on solar research instead.
If we just got all its 212 possible oil barrels, that would have been $4.72 a barrel (enough to get 50M Americans to vote for it), but we probably won't get any of it now - unless we buy it from Iran.
That 750Pj could come from the Sun (at 1KW:m^2) into 4000K square miles (0.1% of the US total area) in 2.5 years. At 25% efficiency, that would be 10 years. We're already halfway through that alternate decade, we've only wasted huge amounts of energy (and life and limb), and are giving Iran the oil (to sell to us at $100 a barrel).
Investing $250M per square mile in American solar production would have actually secured America, especially from the oil terrorists, at home and abroad.
--
make install -not war
Hey, if you have solar panels on your roof, how often to you have to wash them? Do they develop a film that reduces their efficiency?
Computers are useless. They can only give you answers.
-- Pablo Picasso
Current solar cells are ~20% efficient... you can't do better then 100% obviously.
Nobody claimed they produced 60 X the power. In DC circuits Volts X Amps = Watts. 60 times the current does not equal 60 times the power if the voltage is not the same. The article is very clear, the voltage is way down. They make no power claims. It's even implied that the voltage is near zero. These panels may be less effecient than the curent generation. They are working on raising the voltage. Good luck and I hope they come out with some power figures soon.
The truth shall set you free!
The power convesion ratio is not really that important in itself. The only really important measure is $/watt.
Right, and the only thing that matters with hard drives is $/GB ratio? People don't size systems based purely on $ figures; required output weighs into the equation heavily, since systems usually pay themselves back pretty fast. It doesn't matter when you have a whole hillside or roof, but otherwise, size is important, and the more efficient a panel, (duh), the smaller. That matters for space availability and wind loads.
For example, it's not practical to put solar panels on the roof of a UPS truck; you could cover the entire roof, and even on a sunny day, you probably still wouldn't be able to supply enough energy to keep it going on a day's worth of deliveries. Increasing the efficiency matters here. Likewise for say, putting a solar panel on the back of a cell phone.
The other arena this helps in? Wind loads. If you have a residential system with several panels on a tracking frame, if the panels can be half the size, that means a cheaper frame and tracking system, and less of an eyesore in your back yard. Or, alternatively, twice as much power from the same frame.
What really matters is retail availability. I've been reading about advances in solar panel technology for years, and it's dripping into the consumer market like molasses. Why? Well, for one thing, oil companies are snapping up solar intellectual property and companies like crazy...
Please help metamoderate.
Here's a favorite brainteaser of mine. How many commercial power sources can you think of that aren't ultimately derived from sunlight? I've come up with three.
This is one of those grand myths that the public just can't shake. Photovoltaic's have a very good energy return on investment (EROI).
The energy payback peroid for various PV cell types are:
Crystal Silicon: 3.3 years
Multicrystal Si: 0.8 years
CIS: 0.4 years
To put that is perspective of EROI:
Photovoltaics (Si): 60:1 - 10:1 (based on above)
Wind: 60:1
Coal(US average): 9:1
Nuclear (light water): 4:1
Oil (mid-east): 10:1 - 30:1
Oil (US): 3:1 or less
And that is keeping in mind that the lifespan of PV is calculated at 30 years, an arbitrary number picked to equalize it with the life of a coal or nuclear power plant, however are panel warranties are 20-30 years alone. There is no reason to believe that the average lifespan of a PV panel won't be 40-60 years or more.
Spectrolab has cells that are over 40% efficient. See here for more details.
JSL
open source power supply... mehahahaha yes, GNUTowers.
Balderdash!
How about using cheap mirrors to bounce off some extra light unto those expensive solar panels, and increase the output that way. Oh wait ! The solar power companies doesn't want you to know that . . . Or else the corrupt patent system actually issued a patent on that . . . nuts . . .
Recently, I was having a conversation about the upper limit on solar power. I hadn't done the math then, but I just trotted out a fresh napkin to satisfy my curiosity. The earth is 12756 km in diameter. That presents a 127.8 million km^2 cross section to the sun. With the napkin-math estimate of 1kW/m^2 incident at the earth's surface, there's an upper limit of 127.8 million MW of power available from the sun. Okay, so that's an absolute ceiling for terrestrial solar collection - you can't collect more energy than is incident in the first place.
Okay, now for a more practical limit. Let's put the solar collection grid on land - that's a reduction to 30%. Let's also go with solar cells that are 20% efficient - that's not too shabby, but not bleeding-edge-expensive either. (127.8 * 0.3 * 0.2) = 7.67 million MW.
Finally, how much of the available global land mass are we willing to pave over with solar cells? If I use a residential rooftop model, a 1500 sq.ft. house on a 1/4 acre (~10000 sq.ft., sorry for the non-metric-unit shift) property would be about 15%. I think that's probably a bit high, considering that houses aren't aligned for optimal solar collection, but I'm looking for the practical upper limit of solar collection opportunity. Using 15%, the available harvestable power limit becomes 1.15 million MW.
Let's compare that to current consumption stats in the US (no pun intended.) If I read this chart correctly, December of 2006 had 335.6 million MWh of power generated across all industries. There were 744 hours in December, so that equates to 451 thousand MW average continuous power generation. So the maximum solar harvest potential is only about 3x our current consumption rate? Damn, that's sobering.
Where's the news in a half finished project that doesn't deliver any benefits (so far) on existing technologies? Who was the fool that got suckered into producing an infomercial?
t m
This is news: http://www.abc.net.au/catalyst/stories/s1865651.h
Sliver cell solar technology. This was on Australian TV in March. Generating the same amount of power using a fraction of the silicon required today. Brilliant.
Why doesn't Perry think referring to cream cheese as cow fudge is funny?
Can you get some more & better pics? Less emo losers and more hot chicks please.
Those examples are absurd. First we already have a fusion energy source that beams energy from space that can be captured by receivers anywhere on earth - it is called the *sun*. And the receivers? You guess it - solar panels.
The sun just happens to put out wireless directed energy over the whole surface of the earth, energy dense enough to be very useful, yet not too dense as to be dangerous.
No mega clusters of PV are needed. There is 262 billion square ft of rooftop space in the US (according to census data), 246% more surface area than we need to produce all of the US electrical demand with 17% efficiency Panels. That doesn't even count parking lot surface area, or other multipurpose structures.
Light that would turn to heat on your roof, ends up displaced as heat 20 feet away in your refrigerator. No environmental concern here folks, move along.
Even produced at a distance, the net heat balance on the earth is the same. Not so much could be said for fossils or nuclear.
"The earth is 12756 km in diameter. That presents a 127.8 million km^2 cross section to the sun. With the napkin-math estimate of 1kW/m^2 incident at the earth's surface, there's an upper limit of 127.8 million MW of power available from the sun."
I think you mean 127.8 billion MW there, which turns your worrying factor of 3 into a comforting factor of 3,000.
The Department Of Homeland Security has installed new solar panels throughout the United Stares. When asked about the new panels, DHS stated that it is part of the new Early Warning System. However, anonymous DHS insiders have leaked in formation that reveals far more deatils about the panels than is being officially disclosed.
"The new panels are designed to trap more light, so that we can trap it, and neutralize its threat to the American public. After the rougue photons are trapped, they are then sent to Guantanamo Bay, where they undego interrogations as to why they are violating sovereign American airspace, and why they are trying to enter the United States without the proper documentation." said a DHS source on condition of anonymity.
Knowing Google's lust for data collection, the Soviet Union is still alive and well inside the psyche of Sergey Brin....
Actually, boosting the current is just the wrong way to go since they are having trouble with resistance. So, they do want to get the voltage up (not churned out) to help reduce the Ohmic losses (I^2R). With detectors, you usually put on a bias to help get the defects that are causing the resistance filled up, but for power generations you need to rely on the dopant gradiant alone which is probably pretty ragged after they fabricate their nano-posts.s -selling-solar.html
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Eat the reflectance and get it now: http://mdsolar.blogspot.com/2007/01/slashdot-user
including pretty pictures so we can see what TFA is talking about: Science Daily
What kind of lifetime are you expecting?
What about things like theft, hail, wind, tree branches, neighborhood kids with baseballs?
I know it could be a good investment, but these risks somewhat concern me if it will take 10-20 years to pay it off.
Even low-quality solar cells today have around 10% efficiency. Either these things produce a much lower voltage than standard cells, or those claims are bogus.
Anyway. The "problem" with solar cells isn't the conversion efficiency, it's the cost to produce them. If they had come up with a way to make solar cells that are comparable to current models in efficiency but come at 1/60th the cost, they'd have a story.
TFA says they increase the surface area without increasing the dimensions of the panel. But that's not enough.
/. That would double the efficiency of both panels, without the drawback of using nanoscale structures. The panels would have to track the sun for this to work, though.
Let's say that the 3D panel has 10 times the surface area of a flat panel, with the same dimensions. It still receives the same 1400 W/sq m as a flat solar panel, so the amount of solar power going into each sq cm of the panel has to drop to 1/10. It seems to me that the 3D panel wouldn't produce any more power than the flat design.
So there has to be a second effect at work. Let's see if we can find a better article than the information-starved FA? this article claims that the efficiency is increased due to reflections, i.e. each photon has more than one chance of being caught by a PN junction. Ah.
I wonder if this would work on macro scale, by placing two panels at a 45 degree angle to the sun, and 90 degrees to each other, like this \
Before you patronize him, realize the snippet doesn't mention reduced voltage and the story was clearly designed to mislead the layman.
So he's making a valid comment.
Nice Job. You mention "titties" and the Switchtroll's link is now slashdotted.
Which is good to know, but you haven't answered his question. The question was about wind _patterns_, not whether we'll still have wind at all. Yes, the energy will still reach the ground, hot air will still be less dense than cold air, etc, but just like electric current, wind takes the path of minimum resistance so to speak.
Why are the patterns important? Because, for example, it only takes one relatively persistent current changing direction or moving somewhere else, to stop the carrying of dust to the amazon forest and triger an ecological catastrophe comparable only to the biblical flood.
Additionally, although unrelated to the original question, but related to the later "there just ain't no free ride", the wind farms have other problems. E.g., build enough of them, and you're whacking birds left and right. E.g., they tend to vibrate, which some animals and insects in the ground tend to not like much. E.g., they do cast a shadow, just like any other 3D object, so an area filled with those is pretty much an area where you can forget about growing anything, trees included.
Basically the problems are complex enough. Will we have a problem? Maybe, maybe not. I don't know. But just reducing it to, basically, "we'll still have wind" isn't answering it.
Here the straw man gets even more blatant. His question was about how it will affect _life_ in the ocean, _not_ who'll keep powering them, and _not_ how will they influence the _moon_.
Yes, they're powered by the moon, no doubt about that. How will it influence fish, algae, plankton, etc, in the coastal areas though? Because that's where those will be built. Will the shadow from a million generators kill enough photosynthesis there to choke the fish? Will the energy extracted from the water (remember, energy is never lost, it ultimately ends up heat) be enough to nuke one of the permanent currents? E.g., one permanent bogeyman about global warming is the possibility of stopping the gulf stream. Can we achieve the same by extracting enough energy at the source, where the tides are bigger and more fit to drive some generators in the water?
Notice that you can't really answer it as "there'll still be plenty of uncovered ocean", because the coastal ecosystems are often different enough. So they're not a substitute for each other.
Which is at best hand-waving. The implied question isn't whether there's a hidden cost at all, but whether it's a price we're willing to pay.
To give you an example of what's wrong with that hand-waving answer, let
A polar bear is a cartesian bear after a coordinate transform.
They ought to take a look at how much energy it takes to pump petroleum out of the ground, refine it, ship it from one place to another, and then turn what little is left into energy at less than 40% efficiency (closer to 15% on average if it's an automobile). I think the actual net efficiency works out to around 3% or 4%. So that's what other forms of power are competing against.
Seriously, someday people will have to learn to ignore the insane ramblings of rednecks who believe that "alternative power" is a euphemism for the government taking away their guns and forcing them be Wiccans while having to suffer the indignity of possessing civil liberties and human rights. There have been some issues with producing the semiconductors for solar panels in an environmentally responible way (the process has some toxic byproducts), but energy costs are not among them.
.. according to a comment here, so the overall efficiency could even be negative. This is an example of one problem with solar cells, that if you increase efficiency by making incoming light pass through several collecting layers (such as the tiny towers in the article) you also increase the amount of heat (infra-red) collected and risk destroying your panel.
Reduce, reuse, cycle
1 km^2 = 1 km * 1 km = 1000 m * 1000 m = 1000000 m^2. You're out by 1000.
Actually, this approach is a different one to the multi-layered aproach you are probably referring to.
Said multi-layered approaches use multiple pn junctions with differing band-gaps, all on top of one another. This allows them to capture a broader spectrum of incoming light energies, thus increasing efficiency.
The approach referred to in this article is attacking a different problem - using a 3-D 'nano-tower' construction for the pn junctions in order to minimise the reflection of light, thus capturing more of it and therfore being more efficient.
While I'll agree that even this idea for such nano-cells has been around for a little while, it is still in very early stages of development, and has a long way to go. It is encouraging to see apparent evidence that the concept does work, however!
10 square meters can just about power a moped.
Even a home built solar collector with something like 2x2 meters will provide enough hot water for a whole family.
Don't answer me. Moderate. Slashdot is about moderation, not discussion.
The $6/w total you calculated include the wages of the people building the cells, raw materials, investment in manufacturing facilities...
So the financial payback time can be quite different from the energy payback time, depending on which form of energy source is more labor-intensive to make. Also, the market price for solar cells seems currently inflated vs. the manufacturing price.
In Germany, a political discussion has started about cutting solar energy subsidies faster than originally planned, because the manufacturers have made a lot of progress in reducing manufacturing cost and are earning large profits - mostly at the expense of the taxpayer.
C - the footgun of programming languages
The solar energy subsidies are not at the expense of the taxpayer but at the expense of the electricity suppliers (and ultimately their customers).
The electricity suppliers are obliged by law to buy the solar-generated electricity at above-market prices.
C - the footgun of programming languages
Raise the voltage?
Stick it onto a transformer and make the sun blink.
There ya go!
AT&ROFLMAO
Almost. The laws of thermodynamics dictate that you will never get more energy out of a system than you are putting in. The measurement that we're interested in is not the thermodynamic efficiency, but the "thermoeconomic" efficiency. ThermoEconomic Efficiency is the ratio of the cost of the energy in to the value of the energy out.
The 4KW heat pump you mention is only providing 10KW because it is sucking the extra 6+KW from the ground. The key is that you don't pay for that 6KW of ground energy, but you do get value from it. So, thermoeconomically the heat pump is running at 250% (10KW/4KW), but thermodynamically it is running at less than 100% (10KW/(4KW+6KW+friction)
When our name is on the back of your car, we're behind you all the way!
This shouldn't have been marked as a troll. It's a real, informative post. I guess that his point 5 was what attracted the 'troll' rating, but you can't discount the spend on maintaining oil security when comparing energy costs, even if you argue that only a small proportion of the Middle East Excursion is spent on oil security.
Yes, you definately need to work on your reading skills yourself. 60 times more current MEANS 60 times more efficient if they didn't mention the voltage being any less (as this guy already pointed out.) You remind me of the guy who originally claimed he had solar cells with 60x more current...you are just as ignorant!
Besides, even if he had solar cells that were (say) twice as efficent, and with 60x the current. That would mean that the voltage is 30x less. The voltage of solar cells is very low to begin with (0.5V) so the new voltage of these 2x efficient cells would be 1/60 of a volt! Not very useful!! You would need too many of them in series for the voltage to be useful.
Please read the ACs' replies to this, there's an error in your maths. The Sun provides a lot more power than what your calculations tell. Even with 10 % efficient solar cells, only a small fraction of the Sahara would have to be covered to supply the entire world with all the energy we need. Of course, the solar cells would be distributed. I've seen an estimate that covering the parking lots in the US with solar cells would generate enough energy for the country's own use. We will not run out of space.
Hey, If you are that mentally retarded, why couldn't you just do us all a favor and keep your asinine comments to yourself and not post? Any solar cell expert knows that power output (and efficiency) is directly proportional to CURRENT output. Voltage is always a constant 1/2 VOLT. If a 4" by 4" solar cell could, for example, output 4 amperes then thats (0.5 * 4) which is 2 watts. If this cell twice twice as efficient, it would absorb twice as much sunlight and put out 8 amps (0.5 * 8), or 4 watts.
The article doesn't say anything about voltage. If a new cell was invented that doesn't produce the typical 1/2 volt then they failed to mention that. The original comment was PERFECTLY valid and you, my friend, are talking out of your ass!
It's already been pointed out that you fudged the calculation and are off by three orders of magnitude (I did the same thing last week figuring up the usable power output of my roof area on a napkin).
So instead, I'll leave you with this map of what the required area to meet our energy requirements with solar power would look like.
Note that this map assumes a whopping 8% efficiency for collection, too.
What you want is a cell that produces the maximum life-cycle watt-hours per dollar, adjusted to NPV for life time.
Why? Well, if it costs more to make a cell than it will produce in its lifetime, then the cell is only good as an energy storage machanism, like hydrogen. You put energy in one and, and you take it out at the other, but the "out" side has less energy than the "in" side took.
A cell that costs more than 1-2c/kwh to produce is not economical. We can already generate power for 2c or less with nuclear, 3-5c for fossil fuels.
The cells based on this metric alone may not be practical due to size and other factors, but any cell which fails this metric can never be used for net power generation.
Is it just my observation, or are there way too many stupid people in the world?
man, every time I read a /. post about bad math, I think it's about bad meth, and get excited about the flamewar that I'm about to witness, only to ultimately disappointed with the relatively tame flamewar about actual facts.
And I quote: "Inductance?! I laugh heartily at your naivete, dear n00b!"
Please stop stalking me, bro.
Why are the links always to crappy re-statements of the original press release ?
o lar.htm
Here's the original
http://gtresearchnews.gatech.edu/newsrelease/3d-s
Absolute statements are never true
The typical warranties for panels say that they will produce within 80% of their rated power over 25 years. The main cause of the degradation is defects in the crystal structure of the silicon created by cosmic rays. There is a very strong after market for solar panels because they can be used where there is plenty of land, say at a dairy or ranch, where ground mounting is not a problem.
o t-borrowing.html#comment-4164085150001376667.
I like your comparison of EROI. I recently calculated the relative burden on transportation infrastrcuture for solar and coal: On the other hand, installed silicon produces about 200 kWh per pound before it needs to be recycled while coal only produces about 1 kWh per pound for a one time use so there are additional substantial savings on the transportation infrastructure side with solar. here:http://mdsolar.blogspot.com/2007/01/saving-n
I'm assuming 42 lbs for a 250 Wp panel and a 25 year life. If the panels don't move far in the after market, then the solar number probably goes up.
The EROI for hydro is pretty high as can be seen from it's very low price.
11kw would be about 90 amps of 120volt, or 45 amps of 240.
Minimum service install for homes today is 100 amps, my service is currently 60 amps, which I'll upgrade sometime to 200, which is what it looks like they're going to be requiring in the future.
Given that that's probably the systems maximum production capability, not an average, he'll likely only average a third of that. ~2,640 kw/h a month. Or $211 dollars of electricity at my local rate. 20% average and it'd be 1584 kw/h, $127. Still enough to run pretty much all electic, including stuff frequently done by gas, such as heating and cooking.
Yep, he's using a lot of electricity.
I don't read AC A human right
Current solar cells are between 15% and 20% efficient in converting solar energy into electricity. It is obviously impossible to achieve more than 100% efficiency without violating conservation of energy. In addition a 100% conversion efficiency is impossible as that would violate the second law of thermodynamics. So basically there is a fundamental limit to how much you can reduce the cost of solar power by improving the efficiency alone. I have mentioned this before, but just look at solar heating equipment. A near perfectly black surface absorbing light to generate heat is pretty much the most efficient solar collector you can ever get. A dash of black paint will also for sure be cheaper than any solid state device to generate electricity. So unless you live in a very sunny and warm region of the earth ( i.e close to the equator) it will be more economical to use some black paint and water-filled pipes to heat your house than to use photovoltaic cells.
...we can give you lots of current at low voltage. No info at all about the power output or conversion efficiency. I could take an existing cell, slap a transformer onto the output leads and make the same claim these guys are.
You raise good points, and they make a compelling economic case for solar power as long as those conditions hold.
One concern that cannot be dismissed out of hand: if many people start installing solar as you have, it is possible that the 'buy back' programs may end or drastic limits may be imposed, thus in effect removing or drastically reducing the substantial and compelling subsidy you describe.
Think supply and demand: right now, the programs are intended as an incentive to convince people to install such systems because relatively few people have done so. What happens if every third house is selling power back to the power company as you are? Rates will drop, the programs may be curtailed for economic or political reasons.
It's still compelling, but one needs to keep in mind that things change, especially in the political and economic arena - so one should not make plans over ten or twenty years based solely on today's assumptions - risks must be factored in.
Now, if you had a legally binding contract with the power company that locked them in to paying you known rates for power you produce over a ten or twenty year period, that would be an entirely different matter. If that were the case, you'd know conditions up front.
It's kind of like buying stocks on the assumption that the market will rise over the next 20 years because it has risen over the last 20 years. Yeah, maybe - but we all know it isn't guaranteed - so risks must be factored in to the calculations.
The sun does blink. At around 1.15740*10^-5 Hz (If I got my math right).
How SHPEGS works.
You have clearly thought about this a lot more than I have. :-)
Patrick Doyle
I mod down every jackass who puts his moderation policy in his sig. Oh, wait a sec....
The early circuit companies were awful in containing their toxic chemicals.
1. Sure it's a different issue. Solar cells aren't physically logical if they have a negative energy return. Still, it's the same situation as with electric cars right now. They're feasable physically, but cost so much that they're substantially behind other alternatives; making them economically unfeasable in most situations.
2&3. Welcome to the reality of economics. Should be worth it to set up as a solar panel manufacters right now, right? But by economics supply should catch up as more manufacturers enter the field and current ones expand to grab more of the market. For the parent, I'd recommend waiting the said five years for costs to go down and efficiency to go up.
5. Sure, for the same $2 trillion we could build a billion kilowatts of nuclear capacity, producing 8.3 trillion kw/hs annually, or about DOUBLE our annual consumption. And the electricity wouldn't be free, as there'd still be infrastructure maintenance costs and the solar panels have an unknown(but long) effective life. Nuclear requires more maintenance, but I'm sure we could only build half as many plants and spend the extra money on that as well as recycling/eliminating the waste. Also, as you noted, you couldn't physically buy $2 trillion in panels today even if you bought every single one. You'd have to built the infrastructure to do it as well, and that'd increase the price.
I don't read AC A human right
He said "toxic". "Toxic" has nothing to do with payback times, or CO2 emissions.
And since you didn't address it in your link or your post, I suspect you have no answer for it. That may be because you are ignorant, or because you are intentionally avoiding that subject because you know the answer.
Regardless, your wonderfully well crafted post completely missed the point, and refuted a point no one made.
"More referenced research and less willfully ignorant babble please."
Funny, how you say that, then willfully ignore the fact that his post was about "toxicity". So you're an asshole and a hypocrite.
>it will be more economical to use some black paint and water-filled pipes to heat your house than to use photovoltaic cells.
Definitely yes for heating. No, for electricity (at least in principle): Sunlight has a lot of exergy that you waste if you run it through a heat engine on Earth: You're limited by the temperature you can get your hot reservoir. This imposes some fundamental thermodynamic limits:
Via heat engine on earth
Say you use sunlight to heat your 'hot' reservoir to an exceedingly hot temperature. In solar power towers, liquid salt is used, which had a melting point of 1074K -- let's say you get your hot temperature there. Then, say you exhaust heat at room temperature: 22C = 295K. This gives you a Carnot efficiency of deltaT/Th=(1074-295)/1074=73%.
Direct from sun
Solar panels receive radiation from the sun, which is (nearly) a blackbody at 5762K. Again assuming the Earth where you're working is 22C, then you get a Carnot limit of (5762-295)/5762=95%.
So: This doesn't consider the practical efficiencies currently achieved by different technologies, nor the comparative economic efficiencies. But it does show that sunlight has an awful lot of exergy that you throw away by using basically any reasonable heat engine on Earth, and some sort of direct radiation-capturing technology (solar panels, etc) has the potential to be much more efficient.
(woo Thermodynamics.)
Something is wrong there. There is only so much power in sunlight. The best current cells have about 20% efficency. The cheapest are around 5% efficient. Using the low end, 60 X .05 = 3! These things either get 3X the power of the sunlight falling on them (300% effecinecy!), or the article is misleading at the least. I think they mean the cells use a smaller area. (they are concentrating units after all.) This is not a new idea. The problem is that concentrators need direct sunlight. diffuse light (cloudy day) won't concentrate well. Power drops dramaticly. large cells only drop a little (diffuse light is less intense.)
I've seen claims like this every couple of years for the last 25+ years. Before that, I just wasn't paying attention. They still haven't captured the market.
Everybody knows 3 people with my name.
Solar is currently economically feasible in many markets, even with inefficient labor/installation. With electricity at 18+ cents/kWh in the northeast and California, solar looks very good. Now add to that large-scale installation by "virtual" utilities (instead of an installer who does 8 installs a year, a utility scale company doing thousands a year). Labor cost impact would bring system costs very close to equipment costs (10-15% extra for labor, instead of 40%).
Efficiency is not an issue. Nobody is waiting for it to go up. Current efficiencies are 15-20% for Si, 30-40% for multi layer, and 8-10% for thin films. If 10% efficiency thin films can be produced dirt cheap, it will win the marketplace. Efficiency is generally only important if it give an economic advantage.
What about land use? Not an issue. A typical roof on an 2000 sqft house will produce 6 times the amount of energy used by an average American family with 15% efficient cells.
Yes the nuclear question. I didn't check your numbers, but here is a comparison. On a small "large" project I had (30 kW), I negotiated $3.50/watt for PV. For $2 Trillion, we can get 570 million kilowatts of PV. Not quite the same amount but close - but it has no fuel, maintenance, security costs, subsidized loans externalities, insurance backdoor externalities, centralized grid cost externalities, nuclear waste, nuclear proliferation, etc, etc, etc. Still for $ 2 trillion I'd hope we could negotiate better rates!
In fact there is very little going for nuclear, it is very expensive - very close in price to PV. And that doesn't even count all the externalities. We have already spent $1 trillion on it in research & subsidies in the last 40 years... and still it has been a boondoggle, now in deregulated states customers are getting charged another extra "tax" to decommission old plants that are just not economical (as if there weren't enough externalities).
The promise of Nuclear as a source of endless cheap energy was a 1950s dream, it hasn't even come close to the dream. It take a *LOT* on energy to process the nuclear fuel. Notice that Nuclear has one of the lowest EROIs.
I'll just pick one of those externalities to show what is wrong to nuclear.
Where there is no grid infrastructure solar is the cheapest thing going. In developing countries, the cost of adding a grid can cost 10x the cost of the power plants... making solar the cheapest option. We happen to have 75 years of subsidized grid infrastructure in the US. However it is getting old, and every power plant requires a grid upgrade. The grid is the source of most of our power problems in the last decade - not production. More than half the price of electricity in the US is transmission and distribution cost.
One of the missing links in nuclear advocacy, is transmission and distribution. Nuclear power in very centralized by is nature, and requires large grid externalities that aren't counted in its costs. Solar is the exact opposite, as solar is ultimate distributed energy source - it can literally be installed within feet of its primary use.
If today just focused on Distributed solar, we could *downgrade* the grid, instead of *upgrade* it... very big difference in real cost externalities.
I think they forgot that (as the article states) "concentrating solar energy on a smaller area" does not increase the efficiency - it merely concentrates a wider area of sunlight into a smaller area.
Say you have a 100 foot tall 20 foot wide black-coated solar water heater tower. It cranks out a certain amount of BTU, like 5x.
Now take an area of 60000 square feet of reflective panels - and focus them so the sunlight reflects onto the same 100 foot tall 20 foot wide black-coated solar water heater tower. The amount of BTU increases, to something like 300x (60 times the original).
The efficiency is still the same.
In the real world, of course, reflection not only costs money (the reflective panels, tracking the sun), it decreases efficiency (reflectors are never 100 percent efficient).
What has captured the market is the projected constant increased cost of other traditional energy sources, such as barrels of oil, which used to go for $20 a barrel at peak to now $70 a barrel at peak with a floor around $40 a barrel. So the cost-effectiveness of traditional - or improved - solar generation methods is higher, even though they are not substantially more efficient, as you can get more energy from solar for the same amount of money spent on oil than you could just a few years ago (due to the increase in price and demand for energy).
-- Tigger warning: This post may contain tiggers! --
Solar is currently economically feasible in many markets, even with inefficient labor/installation. With electricity at 18+ cents/kWh in the northeast and California, solar looks very good. Now add to that large-scale installation by "virtual" utilities (instead of an installer who does 8 installs a year, a utility scale company doing thousands a year). Labor cost impact would bring system costs very close to equipment costs (10-15% extra for labor, instead of 40%).
.95*. Solar panels can't break 50%, a google search came up with 10% for fixed panels in England. Even if we assume 40%, a watt of solar capacity is half as effective as a watt of nuclear capacity.
Sure, where they've messed up the system, it makes sense. Meanwhile I enjoy 8 cents/kwh power including fuel charge. Nuclear power is around 2 cents/kwh at wholesale. It actually beats all the hydrocarbon ones as long as the power plant isn't essentially situated next to the mine.
Efficiency is not an issue. Nobody is waiting for it to go up. Current efficiencies are 15-20% for Si, 30-40% for multi layer, and 8-10% for thin films. If 10% efficiency thin films can be produced dirt cheap, it will win the marketplace. Efficiency is generally only important if it give an economic advantage.
It was a general statement. A thin film that's 15% efficient for the same price would make for some deals. Same general thing. I'll agree that the cost per watt is the main obstacle remaining.
Yes the nuclear question. I didn't check your numbers, but here is a comparison. On a small "large" project I had (30 kW), I negotiated $3.50/watt for PV. For $2 Trillion, we can get 570 million kilowatts of PV. Not quite the same amount but close - but it has no fuel, maintenance, security costs, subsidized loans externalities, insurance backdoor externalities, centralized grid cost externalities, nuclear waste, nuclear proliferation, etc, etc, etc. Still for $ 2 trillion I'd hope we could negotiate better rates!
I was figuring $2/watt construction cost. There are new proposals at $1/watt, assuming 'type' certification. For the kw/h comparison, I went to CIA.gov to find the annual electricity usage, and assumed a 24x365, with a factor of
As for the better rates - the first nuclear plant for a type certification costs $1.40/watt capacity, subsequent at $1/watt.
As for the waste - build breeder and integral fast reactors. They're more expensive to build, but cheaper to run, as their fuel can be all the 'waste' fuel rods sitting around. Eliminate two birds with one stone.
*What percentage of the plant's maximum wattage it averages. US nuclear reactors average something around 98-99%.
I don't read AC A human right
Not even close. Nuclear is around 6 cents/kWh for current facilities (ranging from 3 to 14 cents/kWh), and that is with completely depreciated capital costs and counting no external costs! Future plants? Please all theory, no reality. The mantra of nuclear is always been "too cheap to meter", yet it has fallen famously short of this for 50 years... why should we subsidize it further? What is the benefit? Causes its super geeky cool? Not enough.
That would be nice. Nuclear plants have historically averaged only 80% up time - in fact in the 1980s is was 65%. Less availability than wind power: 95+% for a good wind farm (surprised? of course capacity factor is a different story). But your point about solar is indeed true, i left it out of my post for simplicity, it averages 30-40%. In fact 85% of the country has 1800-2000 kWh/m^2/year isolation for fixed panels. Around 80% of the best location in Arizona, so no desert needed.
You can't have everything with Nuclear, you either get less efficient use of fuel, OR nuclear proliferation problems. The designers of light water reactor weren't stupid, they designed them to be a nuclear proliferation resistant design. Now, when we are concerned with terrorism, building breeder or fast reactors is insane. Remember is only takes 5-25 kg of material (a softball size) to made a viable nuclear weapon. Its the nuclear materials that are hard, the rest is a glorified pipe bomb - literally garage science.
The main point is with comparatively less subsidy than nuclear, solar and other renewables are kicking nuclears butt in the marketplace already. Next year solar will surpass new nuclear capacity, wind already did it 3 years ago. even with all of the hidden economic subsidies for nuclear. If you add those externalities back in, Nuclear doesn't make any sense. Yes it is cool technology. And it makes sense in a few situations (nuclear subs for example). But that doesn't win one any point: Pollution, scale, distribution, safety (the murphy factor), security, EROI, construction time, cost, etc.
The one flag that nuclear advocates wave is CO2. That is the only benefit, That alone is not enough. Trading 1 waste for another is not a big win - when there are renewable resources that do better, faster, cheaper.
If someone came up with really cheap energy and they didn't sell it to the oil industry they could expect the oil industry to protect its market any way it could. Even by making an unfortunate accident happen to that individual if they didn't think they could contain the threat through lobbying efforts.
When you're talking billions of dollars there are lots of people who will do anything.
The race isn't always to the swift... but that's the way to bet!
Information I'm seeing is ~4-6 cents a kw/h, and that's including paying for the plant over 40 years.
You can't have everything with Nuclear, you either get less efficient use of fuel, OR nuclear proliferation problems.
At this point in time, what with China, NKorea, and Iran, I'm a little less worried about proliferation in US plants. Besides, IFRs are designed to avoid the proliferation that traditonal breeders were known for. Besides, it's not like you have to pull the plutonium out of them much. It's safe in the reactor.
I also love how you go on about how solar and renewables have advanced - and seem to assume that Nuclear hasn't come forward any since the 1960's.
Next year solar will surpass new nuclear capacity, wind already did it 3 years ago. even with all of the hidden economic subsidies for nuclear.
Well duh, we haven't built a new nuke plant since the 80's. All increases in nuclear power during that time was increasing their rated capacity through upgrades. IE a plant rated for 750 megawatts in 1980 might be a gigawatt plant today.
Thing is, we need baseband power. Our choices are pretty much coal and nuclear for that. Heck, your nice PDF points out that almost half of the decentralized generation is natural gas. I've read projections showing that we're draining NG reserves faster than oil. I'd prefer nuclear for a number of reasons, for one it's non-polluting if you do it right. Nuclear power deaths are so low that any are generally reported world wide.
Heck, I saw a blurb about a garbage processing facility that produces power, a NG equivalent, and molten glass as a byproduct. The best part is that no sorting is required. I'd love to see that done, and if it actually makes economic sense like they're promising (cost is half that of what NYC is currently spending to dispose of it's garbage), I'd see them popping up all over.
I don't read AC A human right
That would be nice. Nuclear plants have historically averaged only 80% up time - in fact in the 1980s is was 65%.
They pretty much are - From the article:
To put it another way, the US increase from 65% load factor in 1980s to 90% today is equivalent to adding 23,000 MWe capacity.
Oh, and on the other side; decentralization vs. centralization:
computers won decentralized; but their manufacture is very much centralized at a few large plants.
Please note that I don't disagree that decentralized power has a place in our overall solution. I just think that nuclear plants remain a strong possible solution to certain aspects of our power demand, providing the electricity needed to run factories and cities. Heck, coolocate the plant in the city to give them waste heat. Use some of the newer designs and waste heat to generate hydrogen or desalinate water.
I don't read AC A human right
Yes, the cells may be 60 times more efficient, but will the be 60 times more expensive as well?! I wonder what the optimal break point is where they will be able to take the place of coal or natural gas or oil? When I was a kid, I did a science fair project with selenium solar cels, and was amazed. However, I seem to remember they were toxic as all H due to the selenium. Is is just me, or does it seem that we are trading one poision for the other?