Carbon Nanotube Solar Cells On the Horizon 150
MikeChino writes Carbon nanotube news abounds as of late, and the next application for the up and coming material may be hyper-efficient and economical solar cells. Led by professor Paul McEuen, researchers at Cornell recently tested a simple solar cell (called a photodiode) crafted from a single carbon nanotube. Surprisingly, researchers discovered that more light shined on the nanotube created even more electricity, a huge difference from today's silicon solar cells where excess energy is lost in the form of heat rather than used to create more electricity."
The technology isn't important (Score:3, Insightful)
The question is, it it cost-effective?
New title:
More cost-effective Solar Cells On the Horizon
There, fixed that for you.
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The question is, it it cost-effective?
New title:
More cost-effective Solar Cells On the Horizon
There, fixed that for you.
New solar cells that are "more cost-effective" require new technology.
New technology requires research.
Research is an expensive process.
To make new, more cost effective solar cells, we need to fund _some_ technology. Carbon Nanotubes are promising.
Press releases get a college department more funding, which buys new equipment and affords more people working on a subject area.
So, in short, the fact that this technology is related to Carbon Nanotubes is intrinsically important.
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Considering the energy required to produce crystalline Si cells, if the manufacturing is perfected, it could be both more efficient and cheaper. A solar pv panel today must produce energy for a year or two to recover the energy used to create it. Nanotubes may be much more complex, but they probably need nowhere near as much power to create.
The bottom line Is what generally matters to consumers, but the cells must still be efficient because roof real estate is not unlimited.
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It's a great finding, but unfortunately, making nanotubes is a HIGHLY energy intensive process
Obviously we need someone to invent some sort of hyper-efficient, clean and renewable energy source to power the manufacturing process then.
Re:The technology isn't important (Score:5, Funny)
The question is, it it cost-effective?
If someone developed a 99% efficient solar cell, would you really care what it cost?
Re:The technology isn't important (Score:4, Insightful)
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Perhaps, but I promise you this, at 99% in an energy starved world where energy is one of the driving forces for tension between countries, and world dominance (see middle east and russia) cost becomes much much less important. at $10.34 per kw/hr I assure you no matter what cost you charge there will be investors out there who will finance you.
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no.... if it costs 10x current solar prices to ramp it up to 99% then it doesn't really help does it. I mean maybe for some weird science use but not for energy production.
TFA is a little light on details, but consider this quote: "Researchers discovered that more light shined on the nanotube created even more electricity, a huge difference from today's silicon solar cells where excess energy is lost in the form of heat rather than used to create more electricity."
So say it's 10x the current price of solar cells, but can utilize cheap mirrors so that you only need 1/10 as many of them as conventional solar cells.
There *is* some potential here (assuming it actually works on a
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Current price has just about lowered to 1 dollar per Watt.
The optimum conversion of sunlight hitting the earth would be 1 Kw per sqr meter.
That means at 10 times the current cost you would be pating 10K dollars per sqr Meter.
I currently pay about 10 cents per KW.
So, yeah cost is a factor.
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You're kidding right?
For everyone who is looking for real solutions (unfortunately that's not quite everyone in the debate), the cost is a crucial factor in the equation. Economic efficiency is more important than energy efficiency.
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Economic efficiency is more important than energy efficiency.
they are both fairly important. As stated above, if your launching this into space for a satellite then the Economics is vastly different than if you putting this next to a nuclear plant. If we could just convert a nuclear plant into a dedicated solar cell manufacturing plant, get rid of all the ugly & terrorist target & high maintenance of the power grid, all the middle men (IE Enron, etc) in favor of wal-mart, that changes overall economics greatly. Adding $50,000 to the cost of a Prius to have
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Adding $70,000 to a high end motor home, that then never needs fuel, grid connection, etc. Even if it just provides say 500 miles of travel a week + complete self sufficiency (ok I still probably need to recycle the waste for clean water) Is well worth considering (would trade my house in as a down payment.)
Good luck with that. A 20% efficient panel will collect maybe 1 KWh/m^2 over the course of a mid-latitude day, on average. A typical motor home will have somewhere around 15 m^2 of roof area. That means you can collect 15kWh per day with today's panels. That's enough to run an electric motor at 20HP for a bit less than an hour. Or, looking at it another way, that's about the energy you get from burning half a gallon of gas.
This is all from the back of a pretty small envelope, as it were -- your panels
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For one, 15kWh is about the average amount a three bedroom house uses in a day. That RV would move just fine off of that, and it could still have huge 'dragon wings' as you know, most RVs have those things called hinges that allow those huge shade spreaders on the sides of RVs to fold against the side of the RV while it is in motion. The only problem would be camping in a forest where a majority of sunlight gets blocked. More efficient solar cells made from this technology would pretty much allow truly sol
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For one, 15kWh is about the average amount a three bedroom house uses in a day. That RV would move just fine off of that...
...just not for long.
Most people don't seem to realize that the typical vehicular engine can produce much more power than the typical household electric service. A generous 200A 240V feed equates to about 64 horsepower. At that power level, you consume 15kWh in a bit less than 20 minutes.
Looking at it another way, an RV will typically get around 10 mpg. That means you're using about 3.3kWh of gasoline per mile (energy content of gas is about 33kWh/gal). Assuming you lose about 80% of that to thermodynam
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The thread was more of a hypothetical 99% efficiency what would the value be... It appears with nano tubes a reflector has a bigger benefit, so we could get 20% over not only the panel area, but the reflector area as well. 10meter x 2.2meter motor home roof, with a full length vertical reflector on each side that could automatically rolled out to say 5 meters while parked, tracking the sun would give me 22 m^3 of panel area + 50 m^3 of reflector area (assuming we can choose the optimal parking direction.)
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Yes, this idea of putting down roots and spreading out petals during the peak of the day could buy you quite a bit. However, it also imposes a much greater requirement for batteries, which brings us right back to the other disappointingly stagnant technology. If only we could come up with a high-power-density battery system with a service life much greater than the current few hundred to few thousand cycles, a lot of things would get a lot better.
The best power density I see for current commercial technol
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agreed, were not even close. But I can dream of becoming a super Hippie. Were probably closer to gathering the methane from the black water tank to get home, than packing the 2 tons of batteries around.
Although I just want the pedals on my current camper (trailer) so I can run the AC when it's hot (and maybe hook it up to the house at home). I do think making that trailer a hybrid would be nice first. Be able to even out the hills towing, smart braking around corners, and then charge the batteries down t
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they are both fairly important..
You see my point; If, say, a few square feet of your roof can supply all of your daily electricity needs for the next 20 (or more) years, then what's that worth to you? If a dozen acres of otherwise useless land can supply a city the size of New York, then what's that worth? Naturally the cost of any technology goes down over time as manufacturing processes are perfected and optimized, and as more manufacturers are producing that technology.
Bad examples (Score:2)
I can put a dollar value on those easily, and they better make financial sense, little else matters. In the US Cars are generally a 2-3 year investment, and a house is a 5-8 year thing, both generally financed. Both (as a guy) require me to grab a calculator and figure out the math (because it won't change my lifestyle/activities.) And given the choice of eliminating a $150 per month utility bill at the cost of a $300 mortgage will be obvious (same with the car.) The same isn't true about lifestyles, ho
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The problem with that is, Economic Efficiency is a non-stable and non-quantifiable metric. Trying to calculate economic efficiency results in absurd conclusions.
In the real world, such calculations have 'proved' that the United States doesn't need high speed cargo rail, it just needs to keep subsidising the airlines. It's 'proved' that shipping from say, Nice to Tuniz by truck, through nations such as Lebanon, in time of war, is 'better' than shipping straight across the sea by
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There are limits to how precisely it can be pinned down, but some arrangements are obviously more reasonable than others.
> In the real world, such calculations have 'proved' that
> the United States doesn't need high speed cargo rail,
That conclusion is correct. The problem with any railroad is that it's only practical when huge amounts of cargo (or passengers for that matter) need to travel exactly the same route all the time. We do
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could a 99% efficient solar cell even provide enough electricity to cool/warm/light my home? Of course, but how large of a setup would one need?
Let's see.
according to http://www.wunderground.com/calculators/solar.html [wunderground.com] I have no idea what I'm talking about.
How much electricity do I need in my home? http://tonto.eia.doe.gov/ask/electricity_faqs.asp [doe.gov] says the 2007 average was 936 kWh per month. I'll say I'm average in that respect with a gas furnace and clothes dryer.
that's 11,232 kWhs per year?
At my location,
99% != infinite (Score:2)
If it costs less than 10 times as much as a 10%-efficient cell, I'm all over it. If it costs 100 times as much, I have no interest, unless I'm really constrained for space and/or weight, or installation costs per square meter are really high.
No, wait. If "99% efficient" means only 1% of the incident radiant energy gets past it or gets re-radiated as heat, I'm all kinds of interested. But, of course, that's not ever going to happen.
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Most people in this thread really need to understand something about lifecycle costs. If solar panels were completely free, it still would not make sense for most people to install them on their roofs, because of all the other costs.
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Well, if somebody developed a 150% efficient solar cell I wouldn't care about cost.
Then again, you could use such a solar cell to power some high efficiency light producing device (say, a LED) which you would point at the solar cell thus getting back more energy than you used to power the light (i.e. free energy).
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a 101% efficiency would drive the cost down to just above 0 per KW.
Of course, if we are talking about magic, we might as well hope for a way top get 10KW of power from body odor.
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Yes, I would. If it cost $1,000,000 for enough solar cells to generate 1 kilowatt at 99% efficiency, it would be essentially worthless for anyone but NASA.
What I'm looking for is something that costs $1,000 per kilowatt. That's cheap enough that I could actually make use of it.
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That would be 1 Kilowatt per sqr meter. So, is there a limit to how much you would pay to gte 1 KW for hour, 12 hours a day?
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Yes, there is.
My roof is rather larger than 1 square meter. It's enough larger that I can get 1kW per hour, 12 hours per day with 15% efficient panels.
So, if it costs more than about 7 times as much as conventional solar, it's worthless to me.
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It all depends on the application.
If I'm powering a satellite, I *almost* don't care what it costs. If I'm powering a planetary probe, it'd easily be worth its weight in gold.
On the other end of the spectrum, I read last year about a group working on photovoltaic house paint. That's almost certain to be extremely inefficient. However if it costs about the same as regular house paint, and works about as well, the inefficiency *almost* wouldn't matter. I've got to paint my house anyhow, and I were going
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I guess that would also depend on how much more efficiency we gain through this method.
I think the present state is 30 to 40% or something minimal like that...if this shot it up to 80-90% then I think regardless of cost, the same panel would yield you twice as much power...just let's hope it does not cost twice as much to produce.
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researchers at Cornell recently tested a simple solar cell (called a photodiode)
I'm not a Cornell researcher, but I'm fairly certain a solar cell is not the same thing as a photodiode. Once again, proof that the only way we can make science relevant again is to train the people reporting on it to actually understand what the hell they are talking about!
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A solar Cell is definitely not the same as a Photo(emitting)diode. (and most of the time, when someone says photo-diode that's what they mean). Whether you could justly call a photo(converting)diode a solar cell with built in unidirectional output is really a matter of semantics. I'd go with not conflating the two simply because it's potentially confusing, but then, most people say LED instead of photo-diode these days so maybe the usage is legitimate.
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It just might be cost effective soon. Just a few years ago 100 NM was the longest you could make this stuff in quantity. Now it's up to 1000 NM. That's just barely enough to make fabric and maybe wire.
Homer says... (Score:5, Funny)
Carbon nanotubes... is there anything they _can't_ do?
Re:Homer says... (Score:4, Funny)
They have yet to get me a date with Megan Fox.
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Let's be fair, I doubt anyone perusing these forums has either.
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Re:Homer says... (Score:5, Funny)
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Plenty. In many cases, people just add them to things because it sells. It's increasingly becoming a buzzword. I think Ruby on Rails is carbon nanotube reinforced, and The Cloud consists of up to 20% of carbon nanotubes.
Re:Homer says... (Score:5, Insightful)
Carbon nanotubes can't be mass produced economically yet.
There, fixed that for you.
Yikes, what an article! (Score:4, Interesting)
Did anyone else conclude that article was written by someone who had little idea what they were talking about? Note that "light" doesn't enter the description until after they talk about running power through it. And not one number.
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A photo diode is just a PN junction too.
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and even human hair! [...] Lacking substance...long on hippy drivel.
To be fair, it's only the hippies who had hair long enough to be usable in industrial quantities.
Ooh, ooh (Score:5, Insightful)
Another world changing technology that's just around the corner.
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This didn't sound "just around the corner" because it's pretty basic research and we still need good ways to mass produce the nanotubes. Still, the science there is now proven and it's "just" an engineering problem. Someone fund this... please!
Re:Ooh, ooh (Score:5, Insightful)
Another world changing technology that's just around the corner.
Just for fun, if you're old enough, try to remember what things were like 35 years ago in the mid 70's:
These days the average (new) cell phone is more powerful than all the computing resources used by the Apollo program. Heck I carry my ENTIRE music collection around with me every day!
Now try to imagine the world in 35 years.... it's just around the corner.
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Nuclear fusion was just around the corner. So were high efficiency solar cells. Some things got a lot better. Some things didn't.
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Nuclear fusion was just around the corner. So were high efficiency solar cells. Some things got a lot better. Some things didn't.
Have you read Robert Heinlein's essays on the foolishness of trying to predict the future?
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Except that the things we thought were right around the corner turned out not to be. By now we were supposed to have fusion power and sub-orbital passenger ships. Hydroponics for food staples. A cure for cancer. Cryogenics.
It's not the things you expect that turn out to be world changing. Those things tend to not happen at all or not be as important as you thought they'd be. It may be quite a bit harder than people think to produce these things economically, and there are already a few other technolo
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There's an app for that.
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There's an app for that.
You might be aiming for +funny by tapping that meme, but it turns out you're right [lunarmodule3d.com].
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The moon? you think small. We ahve devices exiting are solar system that were built with technology on the 70s.
Again with the #$##%# solar cells (Score:5, Funny)
Not a week goes by that you don't hear about yet another breakthrough in cheap and efficient solar cells. Every week, without fail, since 1979, I swear to God. Any more grains of salt, and I'll have a heart attack.
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And prices have been dropping. I am only a casual observer, but have seen that manufacturing costs have dropped to under one dollar per watt. I'd really be curious to see a chart of the price drop over the past twenty years, but my google-fu has yet to uncover the information.
Re:Again with the #$##%# solar cells (Score:4, Interesting)
Here is an anecdote I found in my search
"Scott,
The price of PV modules has come down in the last year, although not quite as much as the Times article suggests. I don't think there has been any significant drop in the cost of inverters, racks, cable, or installation labor.
My first PV module cost me $8.33 per watt in 1980. I paid $3.97 per watt in 2004, and $3.99 per watt in April 2009. Current PV module prices can be as low as $3 a watt, but only if you buy a whole pallet of modules. Otherwise you're still liable to pay $3.50 to $3.96 a watt"
So, since the year 1979 which the GP references, prices to the consumer have dropped more than 50%, even without adjusting for inflation. After accounting for inflation, you are looking at solar being 5 times cheaper than 30 years ago. Not bad.
I know it is poor form to extrapolate like this, but if we had a similar improvement over the next thirty years, then solar would easily become the number one source of energy worldwide. that may or many not come to pass, but the overall point is that despite the jaded responses from folks, we are seeing dramatic improvement in the price/performance of solar.
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You extrapolate wrong, though. In your own example, the price has actually risen between 2004 and 2009. Even keeping inflation in mind, the price drop during those three years will come out as marginal. So the curve of this price drop has become quite flat, don't you think?
This implies, IMO, that even though manufacturing costs have dropped, the consumer price has not changed all that much. Obviously, someone is finally making a profit... Or rather huge profits all of a sudden, depending on how cynical you
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The shorter a time period you use for extrapolation (or fewer data points), the more wrong you are. You shouldn't be concluding much of anything from the price trends of the last five years.
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Not really. Adjusting for inflation, we are still seeing a 14% drop in five years, or nearly 3% drop annually.
Also, we are discussing one guy's experience. I'd still love to see a more formal chart of manufacturing costs and consumer cost per watt.
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But solar panels are physically limited. Even if they grab 99% of the energy that hits them and they transfer it cheaply we will still have to make they for almost the same price as sheets of hard plastic. At best solar cells can become
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I don't think you realize just how stupid it is. Consider:
Doubling efficiency from 5% to 10% - relatively easy.
Doubling efficiency from 25% to 50% - hard
Doubling efficiency from 55% to 110% - requires breaking the laws of thermodynamics
It is obvious that if you start out with rubbish efficiency you will see some great improvements when you put some effort into it, but that rapid improvement will stall when you are up to par with what the tech is actually cap
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It is also poor form to pick up on one tangent to the discussion and miss out on the main point, especially when poster already noted that extrapolating was not appropriate. The main point, if you missed it, is that the expense of solar has already dropped a lot despite original poster's belly aching.
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On the plus side, the cost of solar panel is expected to hit 1 dollar a watt by before the end of 2010, and as cheap as 50 cents a watt by the end of 2012.
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On the plus side, the cost of solar panel is expected to hit 1 dollar a watt by before the end of 2010, and as cheap as 50 cents a watt by the end of 2012.
Do you have a link on that?
If true, the only thing remaining would be to drop the ancillerary costs to a similar level. Right now that's running around $1/watt itself.
For example, a 6kw inverter [solarhome.org] runs $3.6k. That's $.50/watt right there, without getting into wiring, mounting costs for the panels, paying for the electrician to hook everything up*, etc...
*You can't count on everyone, or even a significant fraction of the population to be able to do this stuff themselves.
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A Silicon Valley start-up called Nanosolar shipped its first solar panels -- priced at $1 a watt. That's the price at which solar energy gets cheaper than coal. Curious that this story is not on every front page.
Note that the article is from 2007. What I love about their process is that when they run the roll of substrate faster, the process becomes more efficient. And while you're correct, the support equipment and installation aren't exactly cheap, the panels will continue to come down in price making the total installation cost cheaper.
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Show me someplace I can purchase nanosolar at even a competitive price, say, $3.75 a watt for finished panels (ready to glue down or whatever.) I can get seconds-quality panels (cosmetic problems, nothing wrong with them) for $2.75 a watt fairly regularly.
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I'm talking just the panel consumer cost. I.e. you walk into a store and that's your price for the panel.
The panels coming out of China next year are expected to be low cost do to lower manufacturing.
I am not talking about the converter.
Like these:
http://sunelec.com/index.php?main_page=index&cPath=5&zenid=2cb58ed84ab020ff9956e7bcdaa79691 [sunelec.com]
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I'm talking just the panel consumer cost. I.e. you walk into a store and that's your price for the panel.
I think you need to reread my post. I asked for a source on the $.50/watt solar panels, then commented that the next that needs to happen is that the associated costs need to drop - which at that point would be double that of the solar panels themselves, thus a bigger target.
What I said: 'If true, the only thing remaining would be to drop the ancillary costs to a similar level. Right now that's running around $1/watt itself.'
When solar panels themselves were running $4-$5/watt, $1/watt ancillary costs were
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He's talking about panels only.
Thin film manufacturers like FirstSolar have already announced that they are producing panels below $1/watt. NanoSolar is very likely there as well.
Silicon panels have dropped a huge amount in the past 6-9 months with the weak economy. Wholesale prices are close to $2/watt, and you can buy panels retail at $3/watt.
Yes, the rest of the costs to install a system (inverter, wiring, mounts, labor) are quickly becoming the largest cost in a solar system, so expect to see drops in
More Than You'd think (Score:2)
Well, yes and no, you mention a lot of things that could be grouped as switch-mode power supplies.
Making an inverter isn't really rocket science; basically one way to do it is to get your input voltage to say 170 VDC (maybe up from 12 or 24 volts from a battery, or down from say 600 volts from a solar array) and then use that to power a class D amplifier with a sine wave as the input.
Now, that isn't that hard to build. However, for an inverter of the type you might get to feed power from your solar array i
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It's all a matter of timing.
We know at some point petroleum will become impractical to support the energy needs of civilization as we know it. In 1979, people thought the end was nigh, when in fact it was just an oil cartel flexing its muscle. But the ability of the cartel to do this was a harbinger of peak oil. The US was no longer anywhere near energy self-sufficient. The same thing happened in 2008, suddenly the end was nigh. It wasn't.
Let me draw a closer analogy. During the Dot Com boom, lots o
On the Horizon? Really (Score:2)
Though still in the very early stages of development, if perfected, carbon nanotube-based cells could provide a more efficient method of converting light to electricity....
ans
While the device is certainly in its earliest stages of development...
So it uses a rather exotic material and is still in the "earliest stages of development" but is on the horizon? Really? It sounds to me like we probably won't see them commercially available for at least another 10 years...then again, I suppose the truth of the statement depends on one's definition of, "on the horizon," but I wouldn't expect to be seeing these guys in Home Depot anytime soon...
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It's a strange but not rare material -- essentially limitless, but currently expensive to produce.
Re:On the Horizon? Really (Score:4, Interesting)
The important thing though is that with the linear response to photons light can be focused on the cells- even if they are expensive they could possibly be cost competitive with Si cells.
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The last working test is sitting in an eastern window. Get it? East... Window... Horizon...
Sorry.
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The slow rate of solar cell improvements (Score:2)
Is it just me or do we get all sorts of stories about this or that breakthrough but I have yet to see ANY of this stuff make it to wide use (or even in specialized cases). What good is all this research if none of it ever gets engineered into something we can use.
Don't get me wrong. I LOVE science and research but I look up in the sky and see that big freaking nuclear fusion ball hanging there and wonder why we can't seem to get enough energy from it.
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why we can't seem to get enough energy from it.
It's that 8 minute delay. It kills your efficiency.
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R&D takes time. If you want to read articles about scientific developments where you can have engineered results "soon", read publications from 15-20 years ago.
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I think what you are seeing is all the progress in solar is masked by the fact it still hasn't reached the critical threshold of being cheaper than fossil fuel. Regardless of whether it's 20 percent more expensive or 20 times more expensive, it's still not the cheapest option. However, it has been making progress and getting cheaper, w
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No one will jump.
We can power the US on industrial solar power. It takes room and money, but the technology is well known.
Future speak meets now tech. (Score:2, Insightful)
I, for one, thought the article was good for giving us a look into the future of the tech. Based on teh way things are rapid prototyped and built these days I would expect to see something like this hit the markets in 5-7 years, and the price become reasonable with 2-3 years after that. 10 years to a cheap and cost efficient power source is not bad.
Photoresistive, not photovoltaic (Score:3, Informative)
If you read TFA carefully it seems to be describing a PHOTORESISTOR, not a PHOTOVOLTAIC device.
They talk about APPLYING a potential difference across the thingy, and discovering it has a wide dynamic range OF RESISTANCE, not of any ability to generate voltage or current.
We don't need any more resistors, we have enough of them and they don't generate any power anyway.
This article is even more of a major fail than most.
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If you read TFA carefully it seems to be describing a PHOTORESISTOR, not a PHOTOVOLTAIC device.
But they describe it as a photo-diode. I'm going to take a leap of faith here and assume they know the difference.
Oh, and here is a link to the original page [cornell.edu].
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>But they describe it as a photo-diode.
Photo-diodes can be used in resistive or voltaic modes. The original page is not any clearer.
In any case it still an answer to a non-existent problem-- photocells do just fine in full sunlight.
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"We don't need any more resistors, "
Sure we do. That allows for smaller and more versatile devices.
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Holy bleepin diety.
>They have not created an actual photovoltaic device, but have demonstrated highly efficient electron-hole pair generation when the carbon nanotube is illuminated. In other words, they have created a photodiode, not a photoresistor.
Respectfully, NO. To have a diode, you need a junction. If you only make electron-hole pairs, you just have a photoresistor. And if you read previous replies, you see people that have actually heard the author state it only works at very low temperatures
Meaningless (Score:2)
For all solar cells, increasing the intensity (the "amount of light shining on the cell") increases the photocurrent.
It would be nice if the press release had a link to the actual work.
WALL-E ! (Score:2)
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I know you could be going for funny, but there is a project in Israel that does exactly this they have 1,000x parabolic concentrating reflectors that reflect all their light onto a single PV panel.
http://www.greenmomentum.com/wb3/wb/gm/gm_content?id_content=2365 [greenmomentum.com] The image seems to be missing, so here is the Manufacturers site. http://www.zenithsolar.com/ [zenithsolar.com]
Also this Fresnel Lens gets 1,000x concentration but isn't really a reflector
http://www.technologyreview.com/energy/22204/?a=f [technologyreview.com]