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40% Efficiency Solar Cells Developed
gtada writes "A story published at Physorg.com discusses recently published research into the fabrication of solar cells that surpass the 40% efficiency milestone. Such devices would be the high water-mark to date, and hint at the possibility of even more effective technology. 'In the design, multijunction cells divide the broad solar spectrum into three smaller sections by using three subcell band gaps. Each of the subcells can capture a different wavelength range of light, enabling each subcell to efficiently convert that light into electricity. With their conversion efficiency measured at 40.7%, the metamorphic multijunction concentrator cells surpass the theoretical limit of 37% of single-junction cells at 1000 suns, due to their multijunction structure.'"
There is really no shortage of sunlight anyways. If only solar cells could be made cheaply. I suppose this will be great for satellites though.
Suppose I just dump a bunch of Algae in a pond, then scoop off the top flotsam once a week, dry it in the sun, and then burn it?
Would this be more or less than 40% efficient?
It's another gallium-based technology. That's going to limit it. There's just not that much gallium available. 30%+ efficient cells using gallium have been around for a few years, but other than on spacecraft, and the Stanford Solar Car, they're too expensive to be useful. They talk about "concentrator cells", but that means mirrors and trackers, running up the system cost.
Citation: King, R. R., Law, D. C., Edmondson, K. M., Fetzer, C. M., Kinsey, G. S., Yoon, H., Sherif, R. A., and Karam, N. H. "40% efficient metamorphic GaInP/GaInAs/Ge multijunction solar cells." Applied Physics Letters 90, 183516 (2007).
I wonder how exactly they measure the efficiency. Is it energy produced / total radiation given off by the sun, visible radiation or something else?
not even remotely. plants are efficient at converting photons to an immediate energy source but the vast majority is used to keep the existing tissues alive and functioning. esimates I have seen for the efficiency of converting light, CO2 and water into biomass ranges from less than 1% to 5% depending on the species.
Sigs are too short to say anything truly profound so read the above post instead.
Hmm.
- Efficiency: This article talks about brightnesses of 100 suns. Well what about 1 sun? Or fraction of that (cloudyness)? Are these efficiencies realized then too? If not, does the technology still work at or near where that is?
- Power cost: I've seen it said that many solar cells don't give back the energy required to manufacture them. By that I mean, acquiring the materials (mining, etc), refining them, and manufacturing them all take energy. How many days/months/years would it take to "pay back" the cost of manufacture, in energy?
- Temperature performance differences: How does it perform in low (or high) temperatures? A lot of us live in places where it gets cold for long periods of the year. This also has the associated problems with snow build-up, and getting that OFF of the panels.
- Monetary cost: How much will this cost at the consumer level, for which wattages? How big would they have to be to cover some typical consumer usages?
- Power storage: With solar, it all eventually comes back to storing the power, as they obviously don't operate in darkness. So how much would the batteries cost (initially, and in maintenance) to make this a viable power solution? How much wattage would you need to have enough "storage" for nighttime? Or more practically, for a few cloudy/rainy days in a row?
Some of these issues are universal to ANY solar technology, but some of them are specific to this as well. All need real answers.Please research for 30 seconds before suggesting this is true.
when the article talks about hundreds or thousands of suns, it means they used mirrors and lenses to concentrate the light that falls on a much larger area to then fall on the solar cells. this leads to the solar cells generating a lot more electrical power and thus makes it more economical to produce power from soalr energy as compared to not using mirrors or lenses to focus light onto the panals.
Sigs are too short to say anything truly profound so read the above post instead.
Solar is by far my favorite power source. But like every other power source, it is really just a byproduct of the actual energetic reaction. I think I can accurately say that solar power is second-hand nuclear power. Following this reasoning the other power sources may be seen as third-hand nuclear power.
As another posted stated, even if you make the solar 100% efficient (wouldn't that be something!) you still have to store or transport it - since on average the sun is hitting half the Earth's surface at any given time (with much of that surface being water).
I have high hopes for solar - but it always strikes me as strange that we already have this amazing technology of nuclear power - it's here now! We HAVE it!
Plus, nuclear power can make a nuclear rocket! I don't know of any solar rockets yet.
Read my Very Short "Stories"
The cost of the cells is only one part of the expense of the system. With sufficiently inefficient cells, they could never be installed economically. IIRC, it is possible to make amorphous cells for just about free but there's just no point because they are so darn inefficient.
http://en.wikipedia.org/wiki/Solar_cell
If I stick $1000 into a stock tracker. Would it beat the $1000 invested in this technology?
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If I stick $1000 into a stock tracker. Would it beat the $1000 invested in this technology?
...
Depends on cost of production, installation, and any subsidies.
However, the recent IPO of China Solar would have gained you many hundreds of dollars in just a few days
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I agree to a point.
Didn't we acheive this last year using indium-gallium-arsenide?
Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
It depends on what you want to do. If you want something portable you can charge your PDA, smaller is better. If you want to have a charger on cars, smaller is better. If you want to use part of your roof, smaller may be better.
If you're talking about massive power-plant-style solar arrays, perhaps size isn't too much of an issue, but even the more power you can generate in less space means less work and more scalability.
So yes, this depends highly on the materials used and manufacturing process as to whether the energy payback is an issue or not. 1-20 years? Let's hope this technology is on the low end of that scale.
Also, two more issues came up that I forgot in my original post:
- Exotic Materials: The materials advertised in this article are not... common. I highly doubt this helps either the mass production price, or the long-term availability of such.
- Lifetime: How long does a panel actually last? Few manufactured items of any kind have infinite lifespans. Is the manufactured solar cell "stable" chemically/physically? This ties in slightly to my old heat/cold question, but when stressed by weather, will it hold up?
Most of my questions are challenges to be overcome, not "Death knells" to trying. But they're also things to be aware of when anything's announced with too much enthusiasm.http://hardware.slashdot.org/article.pl?sid=06/12/ 06/027228
:)
Ahh well. More publicity for Spectrolabs...
I was really thinking of investment rather than speculation. The point being, if the technology is so expensive that the cost of the electricity isn't repaid faster than say a FTSE100 tracker then it makes sense to invest the money in the tracker and not in the technology. i.e. it's not a go-er.
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But don't forget this. Okay, only 10x concentration, but compact and maintenance-free.
Your god may be dead, but mine aren't!
Applied Physics letter "40% efficient metamorphic GaInP/GaInAs/Ge multijunction solar cells"
This would imply that the three layers are Gallium InP, Gallium InAs (love that Arsenic!), and Ge (oh my!).
The other question is what temperature and weather conditions these cells can operate under. But, since the firm doing the research is mainly interested in satellite power supplies, one could infer they expect this research to be useful in the extreme conditions of space.
Be good to see an actual cost breakdown, but I doubt we'll see it in a letter to Applied Physics, more likely in something in Energy Policy or a journal more concerned with Economic costs.
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Here's the translation of the story for the common person...
"We hand tooled this one-off array that get's an honest 40.7% conversion (if you're on Mercury) and we might be able to make more that the average person would be able to afford (by saving for 10 years) if you give us a follow-on contract." (Voyage to Mercury not included.)
Suppose I just dump a bunch of Algae in a pond, then scoop off the top flotsam once a week, dry it in the sun, and then burn it? Would this be more or less than 40% efficient?
...
This is called biomass. Or, when considered for vehicles, bio-fuel (e.g. bio-diesel for a VW).
Also depends upon how you burn it
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I would recommend investing in Gallium and (dang, forgot, what is Ge) material providers if we end up using this technology on a large scale, quite frankly.
Sometimes you make more on the materials than you do on the manufacturing.
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The lightside could help power the darkside.
Although unlikely any time soon, it would be a nice technology to have.
Um... If it's shiny, it won't absorb any light energy. Anti-relfective coatings are put on many existing solar cells for this reason now...
Yes, and we have the nuclear waste for oh, I don't know, a few HUNDRED THOUSAND years ...
Only with stupid old technology. The Integral Fast Reactor generates 100 times less waste and it's only hotter than ore for a few hundred years. We should be building one at Yucca Mountain as a national security priority.
Fusion will be great in 40+ years, but that's a little late to act. We could have one of these running in probably 5 years.
Solar, at 40% efficiency would still require covering something like 8% of the land surface area of Earth to meet current-day demands. Wind is too variable, hydro is too small - we basically have coal and nuclear as the two viable baseload options.
Obviously, TBPB don't want to end anthropogenic global warming. It's left as an exercise to the reader to speculate on why.
My God, it's Full of Source!
OUTSIDE_IP=$(dig +short my.ip @outsideip.net)
All the more reason we need to establish reliable mining on the moon. Concentrations on the moon are about 80% higher than on Earth. You know, there is a lot of history ahead of us and maybe Lunar mining would allow future infrastructure that at this point in time boggles the imagination.
Shh.
Polywell Fusion is the future.
% 20Go%20Nuclear.pdf6 673788606
http://en.wikipedia.org/wiki/Polywell
http://askmar.com/ConferenceNotes/Should%20Google
http://www.youtube.com/watch?v=jmp1cg3-WDY
http://video.google.com/videoplay?docid=199632184
As opposed to the arsenic in the solar cells, which will remain toxic for an infinite time. Well, unless it's transmuted in a nuclear reactor into some non-toxic element, of course...
until you can amortize disposal costs, nuclear fission will never be the optimal choice
Ironically, right now nuclear is the only energy source that has a system for disposal of waste paid for by the corporations that produce it. Spent nuclear fuel is stored at the plants themselves, inside special containers which have been designed and tested to survive any imaginable disaster for as long as it takes to the radioactivity to decay enough for it to stop being dangerous. Compare this to other types of power plants that dump their wastes into the atmosphere.
Nuclear power plants are the only ones that have spent fuel storage systems built into them at construction time. All other types of energy systems are built with the assumption that someone else will take care of recycling the waste materials when their useful life ends.
the main problem with solar cells
Not to mention the vast amounts of real estate needed. And the indispensable energy storage systems, since solar cells do not work at night, when energy is needed. How much pollution is created making all those batteries, and when they wear down who will take care to safely dispose them? Cadmium, mercury, lead, many materials used in batteries are highly toxic, and are disposed of with much less care than the nuclear industry uses to handle its wastes.
Let's say you're going to do solar on a large scale. Say, an acre.
Making an acre of solar cells is hard. It takes a lot of exotic materials and a very expensive factory.
Making an acre of pond isn't hard. It takes a backhoe, or a number of low-skill workers. And then it takes water. It can even be contaminated water, as long as the contamination is compatible with algae. This is much easier, and much more available to the third world.
We could always recycle them, or use them in our food supply, like melamine.
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And I'm sure we're projected to see them in the magic next 5 years.
"It's the height of ridiculousness to say for those 9 lines you get hundreds of millions."
Solar is great and all but what about the moon? Sometimes it's bright as hell out there but does lunar power get any press? Nooooooooo.
Need Mercedes parts ?
But there is a shortage of space, and load bearing capacity, on my roof, which could make these desirable over less efficient models.
I suppose this will be great for satellites though.
There is no shortage of space in outer space.
"It's the height of ridiculousness to say for those 9 lines you get hundreds of millions."
So what, now we're supposed to detonate nukes in front of our solar panels for maximum efficiency?
This is good news. I can not wait to have affordable solar cells to power a laptop. On board colar panels until now only can extend battery life for a laptop. There are foldable panels which generate enough power (26 watts) for a power friendly laptop: http://www.ascscientific.com/solar.html For a laptop with solid state harddrive and power friendly CPU, onboard solar cells might soon be enough.
My strength is of a thousand men for yea, I am wired to the gills with espresso.
OK, so I didn't quite get the quote right and I can't remember who said it, but you get the idea.
Maybe I have this wrong, but does that mean it just operates like an RGB display in reverse?
Seems like a why-didn't-I-think-of-that moment.
some other powerplant thermodynamic efficiencies:
subcritical coal-fired: approx 37%
supercritical coal-fired: approx 40% (supercritical = no phase transition from steam to water)
gas turbine combined cycle: approx 60%
nuclear: approx 36%
And this is BEFORE the transmission losses in getting the power from the point of generation to the point of consumption. Cost is the ONLY thing holding back massive adoption of photovoltaic technologies -- and nighttime, but the problem of only receiving sunlight for less than half the day is really a problem of how to efficiently store it. Fuel cells make a nice fit technology-wise for an energy storage mechanism, but again, the problem is cost.
In time, technological advances will almost certainly bring down the cost of photovoltaic+fuel cell energy systems, as well as improve the efficiencies of more prosaic (i.e., cheaper) types of photovoltaic cells. And we're probably talking decades rather than centuries.
sources: Wikipedia (Fossil_fuel_power_plant)
I was wondering...why don't the cells get "blacker" in color the more efficient they are? Maybe I'm missing something, but doesn't higher efficiency imply more light is getting absorbed? Or does it simply mean that more light is getting converted to power?
Excess heat kills conventional panels. That's the main reason you aren't seeing mirrors on home systems. Guys have been trying it for a long time and except for some highly tuned exotic systems it just doesn't work all that well. A regular solar panel sitting by itself in the sun gets *freekin hot* to the touch, tripling that would make it a little oven and fry the electronics. Ya, you can do it for a short time frame (I have done some experiments with it), but you'll cook your expensive panels. Try it yourself, go drop 500 bucks on a panel and a charge controller and one cheap storage battery-your basic small scale rig. Now add a few mirrors to the deal, sit back and watch what happens.
Or, send me the 500, a few weeks later I'll send you back 250, you'll come out ahead!
Nope, the real revolution in solar is the non exotic metals and very very little silicon needed cheap "printable" panels/film sheets like nanosolar are putting out. Not as efficient, but much cheaper to make and sell. So you need more of them-so what? Like others have pointed out, for 99% of the PV usages out there, it's dollars per watt, not watts per square meter.
And my bet is hydrogen will turn out to be the "storage battery" that most solar installations will be using in the future.
Anyway, solar is affordable now for most people in reasonably sunny locales who are paying off a normal mortgage-just include it with that (which you can do now most places). And the reason is you get a locked in price for your electricity for the next 30 years. Until your local electrical utility can give you a fixed price per kilowatt hour guaranteed for 30 years-all the speculation on pricing levels and ROI that solar detractors spout is FUD pulled from their stinky orifice.
1000 suns? Why not give everybody the straight story and give a comparison of ONE SUN to ONE CELL?
Chances are, no consumer is going to have 1000 mirrors focusing on ONE cell, only massive solar arrays will.
So, if the cell really is as efficient as they say, each cell should be 40% efficient when it has ONE sun focused on it.
Man, more and more often are scientific claims and reports starting to read like annual corporate reports: Just alot of fancy crap designed to make an insignificant step appear to be an Earth-shattering technological achievment.
BTW, what good is 40% efficiency if you have to focus 1000 suns onto it? I take it this is only for solar arrays AND NOT consumer applications.
Knowing Google's lust for data collection, the Soviet Union is still alive and well inside the psyche of Sergey Brin....
You will do anything to run just coal and gas. That is, until you can figure out a way to own the sun. At that time, you will then own up to loving solar.
Solar energy --> Algae --> oil Here's a company working on this very thing helped along by the clean living Fat Tire Beer company in CO. http://www.solixbiofuels.com/ Trouble is, like everything in this world, it's a pain... ---537
Yes, the efficiency of modern consumer photovoltaics has much room in terms of improvement. Typically, they're still more effective than photosynthesis. However, it's not just efficiency that's a problem - it's environment. The 40+% efficiency being quoted is with hundreds of suns, i.e. with lots of mirrors or lenses in comparison to the semiconductor area size. This is all good and fine, because mirrors are cheap to produce in comparison to semiconductors, but there's still that nasty problem of waste heat. I don't know about their technology, but the current generation of PV is very much allergic to high temperatures. I mean, anything that makes you sweat is going to make the PV cell feel bad as well (i.e., less efficient - specifically, I mean a drop in output voltage). It also shortens their life. If you were able to keep a PV cell at just above water freezing, continuously, it would last 50+ years. But if you keep at at 100F, it's going to poop out at 10-15 years.
Then there's the whole question of control and storage. Semiconductors are expensive per volume, so the desire to use as little of them as possible is not just so you can fit a pentium3-500 equivalent in your pocket - it's so the chip fabs can get more out of a hunk of pure silicon. When you start pumping a lot of current through them, that minor inefficiency, which gets lost in heat, becomes more than just a problem of not being able to use all the electricity you put into the device - the heat builds up and becomes a problem. So, you have to keep a large enough surface area on the devices, so they can disapate heat into either the air or heat sinks or liquid cooling devices. That extra silicon costs money, and lots of it, which is why the power controllers / battery chargers for 500 watt solar cells cost so much. And this gets me back to why I brought up conventional semiconductors in the first place - it's great that they get 40% efficiency, but how much of the energy they harness do they have to spend on fancy cooling systems? How long does this 40% cell last at 10^2 Sols? I imagine that, because they are using multi-spectrum cells, they heat much less than traditional cells (because light of a greater variety of wavelengths is being converted into electricity) but still, what about that almost 60% of the solar power at 10^2 sols? where does it go? into heat, that's where, and you are going to have to get it out of there damned quick. I think that if they could reduce the light intensity required in order to get this type of efficiency, to, say, 10 Suns, we'd have a real winner on our hands.
I wish each announcement of a cell also reported its consumption part of its energy budget.
We're finally getting really efficient solar cells. And they'll just keep coming, with oil costing not just $60-75+ a barrel, but upsetting the never-stable geopolitics that now can kill hundreds of thousands of people in months, weeks or days.
So it's even more important to know how much energy these new cells consume during their lifetime: production, distribution/deployment, transmission inefficiency, maintenance, recycling. Because if we're so desperate for "efficient" cells that we massively depend on them, but their overall lifecycle isn't really efficient, then we'll be burning energy and pumping pollution even worse than before.
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make install -not war
I am currently bidding on an automated solar tester. They use 1 sun for testing the cells, even the ones that will have the sun magnified are tested with one sun.
Actually its all about scale economics. Typically the cells used in arrays in space are made up of cells that are about 2x4 inch. So you only get about 2 cells per wafer.
Now things are being shrunk down, just like everything else. You can get 50 or 60 smaller cells on the same size wafer. Then use a magnifier to put more light on the smaller space, get same watts out. Do you have any idea of the number of suns a 4" magnifying glass produces? These will find their way into your portable electronics, such as gps, laptops etc.
If we could use NASA's new really-remote control drone tech to make really big reflectors on the Moon, pointing at these high-concentration solar cells, we could beam a vast amount of energy down for use on the Earth. 1.3KW:m^2 falls steadily on the Moon, except for dark phases which could be balanced by another reflector on the Moon's other side.
100m^2 on a single m^2 panel at 40% efficiency would be 52KW, or 10 average US homes. Lunar surface area is about 3.8E7Km^2, so the entire current US energy generation could be fed by 2.39 millionths of a percent of the lunar surface, on about 70*70Km reflectors on a half-million Km^2 of Lunar surface.
Of course, by the time we'd scale up, we could have Lunar (or L-point, etc) orbital reflectors consuming no lunar surface, pointing at only 70-100Km of Lunar based cells. By which time the efficiency could be higher, and optical materials that can receive more than 100x full insolation, then distribute it to stacked cells, could be available.
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make install -not war
Thank you... One of the things that originally drew me to reading Slashdot was that when someone would make an outlandish comment, someone else would 'run the numbers'. It's good to see that some traditions are not completely dead.
Take a thousand heliostats concentrated on a turbines boiler or the hot side of a sterling engine and you get decent efficiency numbers on the comparative cheap. A technology that has been, and is being done now rather than futuristic laboratory musings which I must say, makes rather tiresome reads over the course of decades. Yes, it is interesting science and important work to boot but we are living in the here and now. I would be more interested in scaling practical applications of energy alternatives today rather than this seemingly endless stream of announcements concerning potential breakthrough technologies always found five, ten or fifteen years out if ever. In the meanwhile we do essentially little if nothing, neither of which scales very well.
Of course there is the matter of economics which is important and from that perspective the hands down answer is nuke plants even though many dismiss such an energy source as contemptible, it is the most practical solution near term but like a deer caught in the headlights of an oncoming car, we are not moving in that direction either even though we have copious amounts of high purity nuclear fuel stored in our aging arsenals. As if it is better to threaten the world with it over access to oil than it is to burn it up in reactors.
The dilemma of course is that per capita energy consumption is on the rise worldwide, in fact we are fostering such in places where people are not already bound to the gas pump and electrical grid as though we are doing them a favor. One laptop per child indeed. In the absence of any real economical breakthrough in practical energy technology near term, a harsher reality will take center stage. That being the reduction of per capita energy consumption without any technological breakthroughs leaving energy dependent societies in a perilous position OR reducing the per capita side of the equation. People.
Depopulating humankind by fifty percent will have a positive effect on our energy consumption and if we continue to effectively do nothing that will happen via disease, starvation or war. I wouldn't count on the mass euthanasia option given the current state of even our most civil societies even though it is an option and one perhaps we should seriously start to think about. Of course as the energy situation becomes increasingly grim, such an option might become a preferable elective especially for those formerly accustomed to living more comfortable lives.
If we stay true to our current course, the most likely outcome will be global war between those with the military might to stake claims against earths resources for empirical consumption and those attempting to retain preexisting ownership or control. In fact, it seems that has already started and is escalating. That said, I don't expect war to be the final solution for even nations found abundant in military resources will quickly deplete them. What remains from that point forward is simply a blood fight to the knife as modern society collapses worldwide.
With the failure of transportation and technical infrastructure comes widespread panic, starvation and disease eliminating high density human populations. The number of survivors we can only guess at. As to the percentage of current population that might survive and sustain beyond such calamity initially, I would suggest single digits. Ironically, the people most likely to survive are those who currently have the least.
As disturbing as this scenario is, it is not yet to late. It is imperative that we start making better decisions however and earnestly acting upon them with all due diligence if such a future is to be avoided. Not within the next fifteen years, ten or even five. Now.
To whoever moderated this -1 within five minutes of posting:
Please remember your actions head in sand. Not just today or tomorrow, but ten years from now. Not for the small difference it might have made, but for the intention and the potential ramifications of it.
You may not be able to accurately say that solar power is second-hand nuclear power. In this video a group of scientists pretty convincingly debunk the fusion model of the sun and offer a rather compelling electrical model.
Uhh, dude. Hello!
Where have you been for the past 50 years?
They don't grade fathers, but if your daughter's a stripper, you fucked up. --Chris Rock
Toshiba ( IIRC ) just announced they have the best efficiency commercial quantity cells. 18%. lame. Plus, all the cheap thin-film that is talked about, its taking ages to bring it to production.
http://validator.w3.org/check?uri=http%3A%2F%2Fwww.slashdot.org Errors found while checking this document as HTML5!
If you're going to use mirrors, you will likely be better off using solar-thermal generation. Even then the economics of the situation aren't all that good. If your cells are half as efficient then you need twice the mirrors. The structure required to support the solar panels or mirrors has a significant cost. If you can find an example where amorphous cells (efficiency 6%) become economical when you put them in front of a mirror, then your mojo is better than mine.
"Of all of these technologies the solar dish/stirling engine has the highest energy efficiency. A single solar dish-Stirling engine installed at Sandia National Laboratories' National Solar Thermal Test Facility produces as much as 25 kW of electricity, with a conversion efficiency of 40.7%.[8] Southern California Edison announced an agreement to purchase solar powered Stirling engines from Stirling Energy Systems over a twenty year period and in quantities (20,000 units) sufficient to generate 500 megawatts of electricity. [9] Stirling Energy Systems announced another agreement with San Diego Gas & Electric to provide between 300 and 900 megawatts of electricity"
http://en.wikipedia.org/wiki/Solar_thermal_energy
Stolen from Spain.
Do you want to bankrupt the spanish market of solar cells?
They have solar-cell manufacturing plants that run nearly entirely on solar power
At curent (15%) efficiency, you can, most of the time, cover 100% of your electicity use by covering most of your south facing roof. And, when you see smaller systems it is becuaue installer often sell systems that do not cover 100 % of electricity use because customers can't afford that much. You don't actually see much in the way of lower efficiency (few pecent) panels on roofs because then there is not enough roof space and installation costs go up as efficency goes down for the same amount of power. The lower eifficency panels tend to be ground mounted.
s -selling-solar.html
Here is the other constraint on system size: In many states with net metering laws, once you've covered 100% of your use and start to go over (on an annual basis) the utilites stop using a kWh-for-kWh exchange and either pay what is called the avoided cost (less than wholesale) or they just confiscate the power. This leads to an economic limit limit on system size which ususally means that 5x5 m^2 is about as large as you want.
So, a portion of your observation that roof space is left unused is owing to people not having the money to do more, and a portion (typically using less that 60% of available space) is owing to net metering policies.
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Get upto 100% solar for what you your utlity now: http://mdsolar.blogspot.com/2007/01/slashdot-user
The price of a cpu at a given subjective quality level hasn't changed much, i.e. top of the line cpus tend to cost about what they did a few years ago, but if you think I can't get a 1.8ghz p4 for far far less than when it came out, or that the newer chips won't be significantly cheaper in a few years, I'm fairly sure you're way off the mark.
I've been up all night, so maybe that's totally wrong, but I'm pretty sure not. The price of computing has come _way_ down over they years. The price of converting solar energy to electricity has not, and that is the orginal poster's complaint.
Relax I just want some peanuts.
There is more and more long distance transmission as high voltage DC lines get installed. One could start by balancing the East Coast with the West Coast: http://mdsolar.blogspot.com/2007/03/coast-to-coast .html. This works without super conducting transmission. George Monbiot points out
that wind generation far off shore can be economical owing to new HVDC cables.s -selling-solar.html
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Get solar power without long transmission lines: http://mdsolar.blogspot.com/2007/01/slashdot-user
An old idea dating back to the 70s or 80s was the notion of putting solar energy collection onto satellites, converting it to microwave and transmitting it to a small region of earth where it would be received and converted straight to electricity. By using a large enough antenna, the energy density would have been low enough to keep from broiling anything in the area. While there are doubtless all sorts of problems with the approach (like adding to the earth's energy budget, slightly cooking tweetie pie and donald duck etc) it does offer the ability to get around the daytime night time problem, normal atmospheric extinction of radiant enegy at various wavelengths and the very nasty problem of cloudy and rainy days.
.13 / kwh and assumptions of a 6 hr average day over 360 days/yr which are probably a fair average for here. It also assumes a system to suppliment power by feeding back into the power line anything that is not consumed at generation time to reduce the electric bill at full residential rates and that this is not an off the grid system with massive expense of storage for off times.
This article is about concentrator solar cells where light from an area 10 to 100 times that of the cell is focused down on the cell. There's another physorg article linked to the story from 2005. It seems these people are a year behind their own stated expectations. The number of $3/watt for the equipment, probably in very large multimegawatts commercial systems was claimed in the 2005 article to be on the horizon.
For an installed system to cost $3/watt would mean that purchasing it might pay off in 2 to 4 years. Note it's a leap of faith here that their expectations are on and that a small personal system could be done for that price. However, a 3 to 5 year payout for a commercial venture might actually be acceptable.
However, looking at it another way - comparing it to putting the $3 in a savings account earning interest, it would seem that the electricity generation would provide a 9% interest rate for the money, except that eventually, the principle would be eaten up as well.
These numbers are using my own electric bill rates of
It will be interesting to see what sort of longevity results as semiconductors don't like heat and almost 60% of the incoming energy will become heat and the fact that it is concentrated means it's rather like using a magnifying glass to burn something. However, that 60% heat energy might could be harnessed for solar thermal activity as it is likely to be more significantly concentrated and generating higher temperatures than would be something like a typical solar water heater.
Since there was no mention of this or of the potential need for a cooling system, one can only assume that this $3 may not have been referring to anything but the basic solar panel.
Offhand, it may become a race between these high efficiency approaches and the cheap, low efficiency ones like the dye based cells from New Zealand that made the rounds a few months back.
Hazzarding a guess, I'd suspect that the low efficiency dye based ones might dominate the market for home based noncommercial systems while the concentrator high efficiency devices might win out in the commercial power generation market. This is assuming that both can become feasible and achieve fairly competitive cost/benefit ratios at some respective level of generation.
However, for the global warming worrier crowd, solar isn't a panacea. This little thing called albedo or the light and heat energy reflecting back off into space is a rather important factor, possibly more so than co2 if large areas of land are converted to solar power and significantly change the albedo amount. It's not necessarily a deal killer but it's got to be dealt with.
Actually, there is quite a bit of activity in making roof materials that are solar panels. Researchers are working on making the cells more durable and making them look more like common roof treatments and materials.
Also, on thing people overlook is that photovoltaics are not the best answer -- they are part of the best answer. The most efficient way is to direct heat water and provide for direct heating of air. Those panels are cheap. Then use the remaining area for photovoltaics. Trying to run your water and space heating needs from solar panels is very wasteful, requires a lot of area, and is expensive. On the other hand, it is easier to install - just wiring instead of water piping, air ducts, etc.
Your post is a sensible post. What we have now is a desperation-driven solutions engine that grabs hold of the first obvious answers to energy sufficiency, builds a great cradle-to-grave system for manufacturing-sales-distribution. Once such a large juggernaut is in motion, any newer technology that comes along well, it has to fight it like Abraham fighting all night long with an angel. It has to fight with lobbyists & bought-off politicians defending the tax-paying new employers in their State, defending the thousands of jobs that are also PAYING MORE TAXES.
What happens then is a buggy whip manufacturer begins to squelch & strangle better systems like political kudzu. We don't have a mechanism in place to deal with this process, to pay the people their investments back when new buggy whips are made. I have one such buggy whip myself that produces a great deal more electricity than solar cells. I have also figured out several of Tesla's inventions, specifically the one where he figured to draw vast amounts of water up from the ocean surface over to hydroelectric dams built even in the world's deserts. Dams that would run 24 hours a day non-stop til they drop, moisture introduced inland that would increase, even out & stabilize Global Rainfall.
But, there you go. The scientific juggernaut has now decided come Hell or high water they don't want Tesla's water solution. It isn't the only one of Tesla's inventions I have solved. The solar technology wagon is now become a hayride filled with sexy women, drinks being poured in a D.C. bar. To stand in its way or threaten it in any way would harm people's stock portfolios, so that wouldn't be right either. So, my friend, now the "House" is owned by one of the card players and all we can do is watch it burn bright for a while til people realize it needs replacing, possibly 20-30 years from today, maybe. While my systems, real hog-hungry answers, sit on a shelf. It isn't sexy and it isn't fancy but it walks across the Finish Line at the top of the mountain like a 600 hp Caterpillar engine with 48,000 pound loads. Enjoy watching the Race; everyone else is. No sense getting all bent out of shape or pulling out hair or nails by the roots. It is just what this World has to do, that's all, i.e. plod along at Analog Speed. Meanwhile I have been on disability for 17 years. The next 17 should be a cakewalk for me, which only leaves me another 26 and I equal "Bullet Proof Monk"'s 60 years, at which point in time I'll be 88 years old and time to join Nikolai Tesla I reckon.
Industrial Age 2 + How-to Stop Malignant Cancers.
I agree it would be great to be able to mine key resources from the moon. But quite honestly, I think we're all overlooking the root problem of our time, overpopulation. It will take fuel to get to the moon and back, fuel that could be used for any one of a thousand other pressing terrestrial needs here, and I imagine that will be a hard sell. Don't get me wrong, I like your idea, but I think lunar mining (and much else we talk about on /.) will make the most sense if human population is stable, not ever-growing. I'd prefer a scenario of "stable Earth population, with ever growing material well being" vs. 'ever growing Earth population, desperately trying to find more resources". I recall one calculation indicating that at current growth rates, the mass of all humanity would exceed the mass of the universe in about 7000 years. Obviously that won't happen. But it does throw into stark relief, sooner or later, preferably sooner, we're going to have to figure out our overpopulation problem.
I've just set up a tiny pilot project at home in the UK:
7 .html
http://www.earth.org.uk/solar-PV-pilot-summer-200
The manufacturer's warranty on the solar panel is 25 years IIRC.
(The numbers I have for energy payback for the cell/equipment manufacture is around 6 years, BTW, see: http://eprints.ucl.ac.uk/archive/00002642/ )
Rgds
Damon
http://m.earth.org.uk/
One question I've always had in the back of mind is, couldn't we use solar power for manufacturing solar panels? I know that it requires a tremendous amount of energy, but we have capacitors, don't we?
Evergreen Solar has a more efficient and scalable method of manufacture called string ribbon technology. I am an investor.
Link: http://ec.europa.eu/research/energy/nn/nn_rt/nn_rt _dg/article_1158_en.htm. It should appeal to us internet-loving nerds ;-)
To be, or not to be: isn't that quite logical, Slashdot Beta?
Speaking of efficiencies, this article was publish about 3 years ago about a Los Alamos scientist working with Lead Selenium cells on a nanoscale level:
_ get_2-for-1_051904.html
www.trnmag.com/Stories/2004/051904/Solar_crystals
He was trying to get efficiencies up to 60%. Any words on how this is progressing?
http://hardware.slashdot.org/article.pl?sid=06/12/ 06/027228
in the tropics, I can assure you that cloudy days have a massive production impact. I actually live in Seattle now, but spent most of my high school days on a boat in the tropics. Said boat was powered entirely (whenever possible, and it usually was) by 4x 120W panels (that's supposed to be about 120W per 1KW insolation, so 12% efficiency). My chores, among other things, included monitoring the energy levels. Although I do not have as much data as I thought I had, it is online here. (My apologies for site design, I didn't know anything about web programming then).
Although the sample size could be larger and I don't explicitly note the weather on each day, consider 30 Jan vs. 7 Feb. and you'll notice the difference. It was never really grey and dark all day - we were in the Caribbean after all - but many readings on the 7th were far less than half those at the same time on the 30th. Consider especially the 12:45 to 14:15 period... and then notice what happened at 14:30 on the 30th, when production dropped to less than half the average for that hour and stayed that way for 30 minutes. That's a big squall, bit it was *just* a squall; nothing but clouds and rain.
Now consider what the impact on solar production Seattle's weather would be. For those who don't know, it doesn't actually rain the much here; it just rains (or looks like it's about to) constantly. We're up to a week of clear sunny skies at the moment, and its slightly scary. Girls are walking around in bikinis like it's Hawaii (ok, that part is cool). Everybody knows it won't last... and this is one of the best times of year here. During fall through most of spring, we're lucky to get more than a few hours like this in a week, doubly lucky if they fall on the same day.
I'm not saying that photovoltaics can't be used here, but anybody suggesting they would be 70%-80% as effective as somewhere ideal(that's how I read the gpp) is off his (or her) rocker. Clouds have a HUGE impact on energy production, and it doesn't help that we're 30 degrees further north than those readings were taken at so the base insolation is much lower to begin with.
There's no place I could be, since I've found Serenity...
There's no shortage sunlight, true...but there's a shortage on space.
;-)
Two words: Dyson Sphere.
-- Alastair