UCLA Develops Transparent, Electricity-Generating, Solar Cell Windows 163
Elliot Chang writes "A team from UCLA has developed a new transparent solar cell that has the ability to generate electricity while still allowing people to see outside. In short, they've created a solar power-generating window! Described as 'a new kind of polymer solar cell (PSC)' that produces energy by absorbing mainly infrared light instead of traditional visible light, the photoactive plastic cell is nearly 70% transparent to the human eye — so you can look through it like a traditional window."
70% ? (Score:3, Insightful)
so, like about as transparent as your shower door with some soap scum on it? 30% obfuscation seems like a lot...
Re:70% ? (Score:5, Informative)
Transparency is merely how much of the light gets through. What you are talking about is translucency (i.e. scattering). There's no indication from the article that there is significant scattering. It would just look like you had tinting on the window.
Re: (Score:3)
ah my mistake.
Re: (Score:2)
Re:70% ? (Score:5, Informative)
Transparency is merely how much of the light gets through. What you are talking about is translucency (i.e. scattering). There's no indication from the article that there is significant scattering. It would just look like you had tinting on the window.
And not very much tinting, either. 70% transparent would just look like glass, if you didn't have something to compare it to. Even 90% tinting (10% transparent), as long as it is reasonably uniform at different color transmissions, doesn't interfere with vision at all ... sunglasses block more light than that!
Re: (Score:2)
Re: (Score:2)
I think his point was that if you were inside a building that all the windows had the exact same 70% transparency, you'd have a hard time answering the question "is there tinting on this window". Whereas if someone said "here's two windows" and one was 70% and one was 90%, you'd be able to totally tell the difference. We're just not that good at detecting the difference between "full daylight" and "70% of full daylight", unless we're directly comparing the two.
Re: (Score:2)
BUT, 70% might be low enough that when you walked outside and saw how bright it really was, you might think to yourself "oh, yeah... definitely that was tinted in there".
Re: (Score:2)
Actually I was in a lecture on photography that referred to that. Now if we only could make the windows blur out the things I don't like to see......
Re: (Score:2)
I was just thinking this sounds like a nice way to get some power from your tinting. But I wonder how useful it is in reality? And attaching wires to a roll-down window will increase mechanical complexity and add will eventually wear out the wires leading to the window or whatever track mechanism you're going to use to transfer power.
I assume this has been tested to work with safety glass? And you can't tint your front or rear windows legally. Probably would make getting a window replaced significantly
Re: (Score:2)
How barbaric! Don't you know that these days we threaten and harass our neighbors with lawyers, not violence!~
Re: (Score:2)
Simulated windows only work when you are stationary. once you move the illusion dissipates and you only perceive them for what they really are (failed mind controlling devices designed with the disillusioned hopes of making you work harder) from then on.
Re: (Score:3)
Would be more effective to get rid of the windows entirely (or shrink them to tiny size), since there is more energy LOSS through the window than any other part of the house. Thousands of kilowatt-hours of heat (or cool) leak through glass via conduction. Meanwhile the embedded-solar would only generate a few hundred. Overall a huge net loss.
Re: (Score:2)
Okay then explain this image where triple-paned windows in buildings are leaking heat like a sieve:
http://en.wikipedia.org/wiki/File:Passivhaus_thermogram_gedaemmt_ungedaemmt.png [wikipedia.org]
Re: (Score:3)
From the units posted on the graph, the windows in the Passivhaus are emitting radiation consistent with a 1-2C increase in temperature (or, rather, the difference between 37/39.2F and 41F), while those for the traditional structure are consistent with a ~4C increase in temperature (or, rather, the difference between 37/39.2F and 46F). (Compared to double-pane, low-E, R-3 (U-factor 0.3) windows, triple-pane windows (typically R-5/U-factor 0.2) can reduce average heat loss through the window by more than 30
Re:70% ? (Score:4, Informative)
Re:70% ? (Score:5, Informative)
Given that untinted window glass is in the 80-90% range, 70% isn't bad at all.
Remember that you don't perceive brightness linearly. Its several orders of magnitude brighter outside on a sunny day than it is in a very well-lit room inside, but it doesn't feel that way. Think of how many light bulbs you'd need to have to match 1000W/m^2, factoring in also that even fluorescent and LED bulbs lose the lion's share of their energy as heat.
Re: (Score:2)
exclamation marks look terrible here (Score:5, Insightful)
Re: (Score:3)
Thanks! I was wondering how they found me out at the 4th grade science fair.
Want to sound like a snob? (Score:2)
I'm not sure if the summary has been changed since you posted, but here is what I currently see:
XSUNX Research (Score:5, Informative)
Disclosure: I am not an investor or employee.
The company XSUNX has been doing this for a few years with Copper Indium Gallium Diselenide (as a competitor to Silicon and which theoretically is supposed to be better for the environment), generating thin film solar power that you can see through. Their first generation was a smoky amber glass with slight distortion; their current generation film is more like a tinted window.
There's a few people doing similar (Score:3)
Similar work is being done at MIT.
http://web.mit.edu/newsoffice/2011/transparent-solar-windows-0415.html [mit.edu]
For the folks wondering what 70% transparent windows look like, I think the small glass pictured in that article is 65% transparent. Certainly good enough for ambient lighting in an office.
Does it come in styles for Automobiles (Score:4, Interesting)
Its not slow glass (Score:2)
So I'm not interested.
Incandescent bulbs return? (Score:5, Interesting)
produces energy by absorbing mainly infrared light instead of traditional visible light
Unclear how much energy you get in exchange for adsorbing 30% of the visible light and probably all the IR. However, if its a lot of light, it might be worthwhile to dip old fashioned incandescent bulbs into this goo. Rather optimistically, if it can generate more than 40% of the nameplate wattage by adsorbing all the IR and 30% of the visible, then you'd get ahead by recycling that power back into the grid. Not a perpetual motion machine, because 70% of the visible is still leaking out the lampshade, but it would be like the world's weirdest phosphor basically eating IR photons and emitting visible photons.
This does bring up the interesting point for unshaded windows, if it eats 30% of visible light, that merely means you need 30% more ultra-low-R value window area, or 30% more lightbulbs inside to brighten the room back up. So its not going to work well for windows in rooms where the drapes are always open and people are always inside. Great idea for my garage or bedroom (why do those have windows, anyway?) terrible idea for my office / kitchen / living room. Solar panel covered shutters seem like a good idea for the garage and bedroom... if the panels are rockin don't come a knockin or whatever.
Re: (Score:2, Insightful)
Bedrooms have windows so you have at least two escape route in case of fire.
Re: (Score:2)
Bedrooms have windows so you have at least two escape route in case of fire.
A door would be cheaper and better insulated than any window.
Re: (Score:2)
What if there's a fire by that door? (Do you mean multiple doors?)
Is a door really better insulated when there's usually a crack below the door (and it's likely not perfectly sealed on the other edges too)? It seems like most outside doors aren't insulated well.
Re: (Score:2)
They are if you're Rick Santorium
Re: (Score:2)
It can't be more efficient than using light sources that don't emit the IR radiation in the first place.
If a room is well-lit by windows, you don't need any additional window to remain well-lit. A 30% reduction in light for something that's well-lit, particularly by daylight, is not really noticeable. (Rather, you can only tell if you have both available for comparison. If you reduced the transmission of your windows by 30%, your eyes would simply adjust.)
Re: (Score:2)
Yeah, that gives me a great idea! (Score:2)
We'll just make a heat reservoir and hook it up to a heat pump that pumps in heat from outside with a COP [wikipedia.org] of well-greater-than-1, and we'll surround the reservoir in highly efficient IR-absorbing panels, which will capture almost all of the energy, driving the heat pump and yielding energy to spare. Perpetual motion! Take that, laws of physics!
Whether you're dealing with a physical "engine" or not, Carnot must be obeyed, because if he's not, a high-COP heat pump can pump in more heat against the gradient
Re: (Score:2)
Generally, daylight produces more light than you get from light bulbs. Your eyes adjust so you see just as well either way, but most of the light is unnecessary and eventually devolves to heat.
That heat is useful in cold climes, and obviously this device will be most useful in sunny places. At that, it might even help cool the room as well as producing electricity.
Re: (Score:3)
In cold climates, these panels may not be a good idea since instead of reflecting IR, it absorbs it. So, a part of the energy spent to heat the building will feed these panels instead of heating the inside. Again, we need more data to compare both alternatives.
Re: (Score:2)
Well, as mentioned elsewhere, you're limited not just by the standard issues of solar cells, but also by more relevant entropy limits. If your solar cell is being hit by ambient radiated heat IR and is radiating IR in the same range, it's impossible to generate power without violating the laws of thermodynamics. Even though it's not technically a heat engine, you can treat a solar cell as an indirect heat engine subject to the limits of Carnot's theorum (as Carnot's theorum is simply a direct consequence
Re: (Score:2)
That said, if adsorb really is the technically appropriate term here, I
Re: (Score:2)
Incandescent bulbs are hot from heat, not IR. There's a lot of IR, as well, which may make this kind of coating worthwhile; but, the heat will still radiate.
Re: (Score:2)
if you could work out the whole 'light uses AC, generator makes DC' issue while maintaining the cost advantage.
Incandescents work perfectly on DC. You other argument was important though.
Nice thought, but I just don't see that working. I like incandescent too because they are instant on, (I have yet to find a fluorescent that actually works like this)
fluorescents are slow, true. Try Leds for the instant-on places (like the bathroom, it's hard to aim in the dark), if your house wiring is good enough. Do you really need instant on in the living room? That blinding brightnes at the moment you flip the switch? I'd hate it. I love my slow dimmable fluorescents for those applications.
works in all temperatures (from -40 in winter for outside lights, fluorescent come on VERY slow in winter)
There are low temp fluorescents. They still contain a significant amount of mercury (normal fluores
Make it controllable (Score:2)
If this stuff could be further developed so that you would be able to turn it on and off like smart glass it would be a good alternative of shades, generating electricity from excess light. Trying to only convert IR light is a clever idea, but the electricity you get from that isn't much, you are much better off putting a panel on the roof.
Spy product (Score:5, Interesting)
So if I replaced a section of optical fiber with this stuff, it would look on the OTDR like the worlds most uninteresting little bump (oh look, sloppy winding in the splice case results in a minor bump, eh who cares) and I could detect the electrical field... Sounds like a optical tap design.
Of course a beam splitter would probably be a lot simpler, but supposedly there does not exist a beamsplitter design that doesn't inherently create what amounts to multipath that "looks like a beamsplitter" on a OTDR so simply doing something weird when you're tapping might help avoid detection.
The only undetectable optical tap I can think of is chilled-PMT based... I think that would be fairly undetectable if done right.
I haven't directly hands on done fiber since early 90s so I'm not sure. Probably fiber work is much like IT and CS, there is nothing new, just recycled old ideas along a baseline of slowly increasing speeds.
Insulation Properties (Score:3)
Re: (Score:2)
UV (Score:2)
If it could have used UV instead of infrared, we could have energy-generating sunscreen!
Obvious response (Score:2)
When first shown such a window, aren't we all going to say " I see what you did there" ?
Price? (Score:2)
Re: (Score:2)
Re: (Score:2)
You don't need to be "off the grid" to have solar. In fact, having solar tied to the grid makes the most sense nowadays (IMHO).
If you generate enough solar, you can still be zero net usage from the grid, but the grid is your "battery", so you still have power at night for example without your own energy storage.
If you're using the power at night, it's (1) cheap, and (2) you're basically using the baseload power that was being generated anyway.
Generating during the day, you're generating power at the most e
Old... (Score:2)
Way to claim you innovated something when you really didn't!
Re: (Score:2)
If you don't care about environmentalism then why go to a "lame environmentalist convention"?
Re: (Score:2)
If you don't care about environmentalism then why go to a "lame environmentalist convention"?
obviously he's a demented fan of a wild, untrimmed thatch
Re: (Score:2)
For large glass buildings? (Score:3, Insightful)
Depending on the efficiency, it might be an interesting choice for something like one (North or South) side of a large glass building, effectively giving you a large solar array for windows that you were going to put in anyway.
4% (Score:3)
"With this combination, 4% power-conversion efficiency for solution-processed and visibly transparent polymer solar cells has been achieved."
Okaay...
Re:4% (Score:4, Insightful)
These could be particularly useful on large skyscrapers
Re: (Score:3)
Really depends how much that 4% costs.
If the windows are a lot more expensive don't expect much conversion (pardon pun).
Also the ease of use. If hooking up 4% worth of power to your home and/or the grid is expensive, also do not expect much conversion. (batteries, inverters, wiring, smart meter, etc... is it really worth doing all that for a handful of watts?)
If you want conversion, make it economical and easy.
Re: (Score:2)
Re: (Score:2)
In fact that is one of the ways a greenhouse works. Light enters through the glass, hits the ground (covered with black plastic or dark earth) is converted to IR and radiates out from there. Some of it will hit the plants, some of it will miss and hit the glass. The glass reflects most of it back again. Some of that reflected IR will hit the plants, some will hit the plastic/earth and warm it, and so on.
This wa
Re: (Score:2)
That's why you can control temp by covering the ground with a white reflective surface; the absorption and re-emission doesn't happen - the short wavelength IR is simply reflec
4% conversion efficiency (Score:2)
Whee.
If it blocked UV instead (Score:3)
Blocking UV would have some benefits as well.
I seem to recall IR it is blocking is also a major part of heat transference. There could be some definite savings on cooling bills throughout the sun belt/southwest.
Anybody else reminded of the Heinlein stories where Solar panels took off when they started generating energy from the full range of cosmic radiation bombarding the Earth? Led to commuter roads in "The Roads must roll".
Conservation is oppression (Score:2)
This is why I am in favor of technology developments that focus on energy generation. I'm against using state power to artificially drive conservation because most of the time that really means making access to energy more expensive. The end r
Re: (Score:3)
"Electricity-generating solar cell windows"? (Score:2)
"Electricity-generating solar cell windows"?
As opposed to solar cells that that generate, say, xenon and mummy dust?
Re: (Score:2)
Don't worry, Some politicians will request a new stimulus package because throwing money in the air has worked so well so far. We will end up funding those Chinese with money we borrowed from them in the process _again_.
Re:More liberal bullshit. (Score:4, Funny)
Re: (Score:2)
They're even renewable!
The oil industry's already on that ... (Score:2)
Re: (Score:2)
We should be burning them instead.
We are [blogspot.com]
I wonder if we can make a window that absorbs bomb blasts (In some places there's more of that than sunlight.) and generates electricity.
Re: (Score:2, Funny)
Re: (Score:2)
Re: (Score:2)
wouldn't that be fossil fuel that's not being released into the atmosphere, but rather captured and stored as a solar cell? seems like a good idea to me.
Re: (Score:2)
Re: (Score:2)
Re: (Score:2)
There was actually a recent episode of the Straight Dope podcast (which is just reading the weekly column) that covered this. It was a followup to a recent episode that doesn't seem to be available in the feed anymore..
The main feed is:
http://straightdope.infoble.com/rss.xml [infoble.com]
Followup: How much energy is wasted hauling around U.S. body fat? 4/28/12
Re: (Score:2)
Re: (Score:2)
Off the top of my head, I can think of a few reasons this won't work in my house during the summer, when the sun is most plentiful and we have the least amount of overcast days where I live:
Why must it always be one way or the other? (Score:2)
It's really not that complicated. If it's cheap enough, and produces enough power, it will be useful for some people, but will probably not replace Grid Power (though it may help reduce consumption of Grid power, which is generally a win). For other people, because of their circumstances, it will not be so useful.
Therein lies the great, simple truth that most advocates on both sides of the argument ignore.
Solar power (and wind power) isn't a 100% solution for our national energy needs. That doesn't mean it
Re:Tell me slashdot... (Score:4, Interesting)
"Our new PSCs are made from plastic-like materials and are lightweight and flexible," he said. "More importantly, they can be produced in high volume at low cost."
Of course, I'll believe that when I see the bill. However, if it works as they say about the only downside is that you won't get as much heat during cold winters through the windows. That's actually about it. Oh yeah, and they are polymers so they may require oil to be produced (maybe, not sure and don't care enough to find out). Maybe some Slashdoter could get worked up about that or something.
Re: (Score:2)
The reduced heat in the winter is probably offset by the reduced heat in the summer (for those using AC), but...
You will also have 30% less light coming through your windows. It's going to get dark inside your house earlier in the evening, requiring you to turn on lights.
Using a transparent (or even opaque) film on the siding makes a lot more sense to me.
Re: (Score:2)
Re: (Score:2)
Re: (Score:2)
Re: (Score:2)
Re: (Score:2)
Oh not this bullshit again. That was for space-grade solar panels as used on satellites, not all solar cells.
Re: (Score:2)
In fact, the data that I've seen shows that one type of solar cell (CIGS) can actually *increase* in power output over time. Unlike with silicon cells, where there's a small (usually tapering off) loss over time, the "damage" from ionizing radiation can help remove defects in CIGS cells, functioning as a slow annealing stage.
Re: (Score:2)
This is much more interesting for commercial building use than for the home. At home, you're better off shading your windows and just using less AC. Once you get above tree height the math goes the other way. Cover as much of the facade as possible, including vision glass, with photovoltaics. They're already using both transparent and non-transparent photovoltaic on tall building facades.
Re: (Score:2)
Re: (Score:2)
Even if solar is far away or never will become a primary energy source it makes a great backup or supplementary source of power. I live in a house that is covered almost entirely with shade except for a portion of my garage. That small portion of garage is another to charge up a dozen of my DC gadgets.
It's not a lot, but it is something. Think of the exposure to sunlight that cars have on the road. Yes... if you can get enough juice out the material it could top off you battery nicely.
Re: (Score:2)
Fascinating, because just from a quick Google search I find a company selling~30% efficient solar cells [spectrolab.com] today, and that Sharp is at 43.5% [cleantechnica.com] in lab cells. I swear I've seen cells in the 30%s being sold commercially (albeit at very high prices), but I forget which company it was.
Re: (Score:2)
Re: (Score:2)
it's all relative. The problem with traditional solar panels is there's a limited area you can place them - typically on the roof, and often at an angle to get the most sunlight, thus reducing the number of panels further.
But if you look at most office blocks, they're practically all glass. Even at 1/5th efficiency of traditional panels, if you can put at least 5 times as much area of them in, then you will get more power out. Ratio of window to roof on a modern skyscraper towerblock is a lot more than 5:1.
Re: (Score:3)
Re: (Score:2)
Re: (Score:2)
That was actually butt-obvious from the context already (especially to anyone who has spent more than three seconds ever checking out solar panel pricing). IMHO you didn't really need to clarify that, just to satisfy some pedantic egotist trying to demonstrate their superiority by pretending your use of units was confusing to anyone 'clued up'.
Re: (Score:3)
30 years ago, photovoltaic panels were an oddity. Your average person never saw them. Today, they are everywhere. You can't walk through a Walmart without seeing them all over the place for
Re: (Score:2)
Why is it that every time a story is posted about a new solar technology, someone replies to say, "We keep hearing about new solar technologies, but they won't make it onto the market for years." Wrong! All these new solar technologies you keep hearing about are making it onto the market. That's one of the reasons solar prices have been dropping like a rock in recent years.
Re: (Score:2)
Two things:
1 skylight. Now get the efficiency of a roof top solar panel... with electricity.
2. Blocking IR is huge for windows. We have a few south facing windows with no shade... just blocking IR through them would be huge (I have thoiught of it before too). Especially in the summer, every unit of energy that I don't have to extract and remove with the AC units is money saved.
Anything on top of that, even a little extra electricity (maybe enough to operate the blinds?) is gravy.
Re: (Score:3)
3. Twenty story buildings generally have more glass space than roof space.
4. You could put 20% efficient panels on your roof, put 4% efficient film on your windows, or both.
Re: (Score:2)
Especially if you'd be tinting the windows anyway. If you can make this stuff for not much more than regular window tinting, then it might end up way ahead of photovoltaics on the roof.
The questions would be (i) how much more expensive than regular tinting, (ii) how much more/less heat ends up in the building versus tinting (this stuff may be more efficient or less efficient at keeping summer heat out of the building than straight tinting) and (ii) what's the cost of the additional wiring you'd need (as yo