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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
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?
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.
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!
You're talking about two different types of measurements for solar cells.
The statement "60x the current" has almost no relation to the maximum theoretical conversion of sunlight efficiency. It completely leaves out the voltage problems inherrant in these 3d designs. The total output measured in watts or VA would be somehwat more comparable to your "20 percent efficient".
Learn some math before you post.
) Human Kind Vs Human Creation
) It'd be interesting to see how many humans would survive to serve us.
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?
No. There is simply more power in the Earth's wind than we could harvest. Or, if you please, the current annual input of power into the atmosphere is greater than the total energy cost of human civilization, by a few orders of magnitude.
Remember: every single watt of solar power that reaches the ground winds up in the atmosphere as heat, the foundation of wind.
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).
If, and ONLY if, the solar panels were not only almost perfectly efficient, but also sucked energy from heat in the atmosphere.
Same sort of thing goes for tidal energy. If you collect enough, you are going to affect life in the ocean.
Tides are powered by the moon's gravity, bub. Sure you'll have an effect, but the tides are already affecting the moon's rotation.
There just ain't no free ride.
Depends on what you means as "free." Sure, the soup kitchen needs someone to pay for the soup, but the bums getting a hot meal get to enjoy someone else's largesse. Most of the power sources available to humanity work like that, including photovoltalic solar, fission, and hydroelectric.
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!).
Why isn't this tagged "itsatrap"???
Agent K: A *person* is smart. People are dumb, stupid, panicky animals, and you know it.
They'd offer it to the power distribution and oil companies - probably on terms that guarantee a revenue stream well past the expiration of any patents on the technology. Why handle the messy details of dealing with the Great Unwashed one-on-one, when others who could be your customers already have the billing systems and the customer bases in place? And with unlimited clean near-free electicity to play with, the oil companies would find ways to produce hydrocarbons from sea water and atmospheric carbon dioxide pretty damn fast - they've got the storage and distribution expertise, and from a storage and usage perspective you have to admit that fossil hyrdocarbons are pretty damn convenient (if not particularly good for the environment). Synthetic hydrocarbon fuels would be carbon-neutral - the waste products are the same as the raw materials, water and carbon dioxide.
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.
Large buildings and cities have much more of an effect on local wind patterns than wind farms do. "Global wind patterns" on the other hand occur in the atmosphere above any of this. You know, the atmosphere that extends up a few dozen miles, or many thousands of times higher than a wind turbine? Your claim is like saying a thin film of bacteria at the bottom of a river will affect the water current. Global warming, on the other hand, affects a large portion of the atmosphere and will likely cause changes in the wind patterns.
Solar panels don't cool the Earth's surface. Actually, it's the opposite as their albedo is lower than that of desert sand so more of the sun's energy is trapped instead of being reflected back into space. However, even if the entire southwestern US was covered with solar panels this effect on Earth's total albedo would be far less than the effect from the loss of the Northern polar ice cap (white ice suface being replaced by dark water). Beaming solar energy from space would probably be slightly worse than covering the deserts with solar panels, as this adds energy to the system that would otherwise not hit the Earth (most electricity is converted to heat when used).
Collecting tidal energy only affects the immediate surroundings of the facility. Certainly you should make sure to build this stuff where it doesn't cause harm. But it cannot change the effects of the tides anywhere else, as the tides are driven by gravity and Earth's rotation. These are things that can not be significantly affected by anything we do, unlike the atmosphere which we are affecting by continuing to emit huge quantities of CO2.
You should quit believing in the moronic strawmen concocted by people who oppose environmentally friendly technology. All of these are perfectly viable and a LOT better than coal.
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'
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.
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
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?
What is the point of even talking about sixty times the current? In a short article with little technical detail, and no mention of efficiency, this only seems to like an attempt to mislead people into thinking something important has been accomplished.
a,e,i,o,u and sometimes w and y (at be if of up cwm by)
You forgot Chuck Norris.
If I have seen further it is by stealing the Intellectual Property of giants.
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
--
Eat the reflectance and get it now: http://mdsolar.blogspot.com/2007/01/slashdot-user
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 \
I have yet to post this, but it was all I could think of,
You must be new here.
Paying taxes to buy civilization is like paying a hooker to buy love.
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.
That's really not true (about wind). It's entirely conceivable that humans could use almost all available (near-ground) wind power, if we chose to make that our only power source. And long before we even get to harnessing 10% of the available wind power, you're going to see big changes, like climate shift, thanks to the reduced power of the winds.
That's completely, totally, laughably wrong. MOST light that hits the ground is STILL reflected outward, back into space. And a significant amount of the light that is absorbed, is STILL radiated back out into space, shortly thereafter.
The rest isn't necessarily converted into wind... You don't just need high temperatures, you need significant temperature *differentials* to generate appreciable amounts of wind.
Complete nonsense. You don't need near 100% efficiency, much lower efficiencies will do a perfectly good job reducing the temperature of the deserts. And you certainly don't need to absorb heat... The deserts get most of their heat from the sun hitting the ground, not from some magical source of "hot" in the atmosphere.
Did you have a point, here, other than baselessly brushing off his concerns? "[Having] an effect" could potentially be very bad.
Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant
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!
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!
That's not what the comment you linked to said. It simply said to "maximize efficiency". Nowhere does it imply that the cell isn't as efficient as current flat plate technology is. Further, it stated that a hybrid cell using this technology (and some other one I don't know about) can get 60-70% efficiency, though the comment didn't cite anything to back that up.
As for the heat, why not just cyphon off some of the energy to power some cooling fans built into the frame of the panel? I don't know if it would work well enough, but I'm sure it would be at least somewhat effective.
"Growing old is inevitable; growing up is optional."
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.
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.
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.