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Japan Power Technology

Film Turns Windows Into Solar Panels 186

Posted by samzenpus
from the peel-and-stick-power dept.
itwbennett writes "At the Ceatec electronics conference in Japan this week, 3M is showing film that turns windows into solar panels. Although the product only generates about 20% of the electricity of a traditional solar panel, it will cost about half as much, is much easier to install, and takes up no additional space. 'An average person could go to the store, buy some of this, and then bring it home and install it themselves,' said Yasuhiro Aoyagi, a senior manager in the company's construction markets division."
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Film Turns Windows Into Solar Panels

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  • by tverbeek (457094) on Wednesday October 05, 2011 @04:12PM (#37616876) Homepage
    It's about time someone found a good use for Windows.
  • An average person could go to the store, buy some of this, and then bring it home and install it themselves

    Only if the average person happens to also be an electrician, or at least someone knowledgeable enough to plug a small power plant into their house's electrical system without ending up a "Dumbass Killed Tonight In Apparent Electrical Fire" headline on their local news.

    • by Abstrackt (609015) *

      I imagine that if/when this tech is available at the hardware store there will be companies selling borderline-foolproof kits.

      • by roc97007 (608802)

        You can already, this very day, buy solar power solutions at the big hardware stores, and no, the kits aren't foolproof unless your use is trivial. For instance, setting up a single-use circuit, like to power a freezer, isn't hard. (And incidentally, that -- powering fridge/freezer -- is a great use of solar and a good introduction to the technology.) But you still need to know which end of a screwdriver to hold and have some rudimentary understanding of electricity.

      • by Rei (128717)

        Nah, then people will just invent a better fool. ;)

        • by Abstrackt (609015) *

          Fools are like bacteria that way: 99.9% of them aren't a problem, it's the 0.1% that slips through that you have to worry about.

      • by Macgrrl (762836)

        Only two things are infinite, the universe and human stupidity, and I'm not sure about the former. Albert Einstein

    • plug a small power plant into their house's electrical system

      A very very small power plant. TFA says it's enough to "Charge an iPhone". Assuming you're charging over USB, an iPhone pulls a max of 500ma at 5V, or 2.5 watts. Not enough energy to warrant upconverting it to AC, given that there's efficiency losses there. Given that you can only charge your iPhone under the best of circumstances, this seems like yet another not-market-viable solar technology. But, ya gotta start somewhere. Maybe they'll make it better. None the less, the applications are on windows

      • Funny thing, people generally prefer bigger windows on the sunny sides of their houses...what with the natural 'light' thing and all :)

        While they won't be angled outside of vertical in most cases, it is an interesting use of an existing space to produce power. Much like the solar shingles [wikipedia.org] that already exist.

        Enough of these things that make existing space dual use and pretty soon it becomes a significant input to the power supply with little effect compared to installing solar panels on top of the ro
        • by roc97007 (608802)

          > Funny thing, people generally prefer bigger windows on the sunny sides of their houses...what with the natural 'light' thing and all :)

          > While they won't be angled outside of vertical in most cases, it is an interesting use of an existing space to produce power. Much like the solar shingles [wikipedia.org] that already exist.

          So, I have a house with windows facing south, and am at a northern latitude, so I really do get exposure for much of the day. That's not, as it turns out, where I put my solar

        • by zennyboy (1002544)

          I live in Spain. In general (our house included) we have NO windows facing the sun...

          • Is it common to have 'no' windows on the sunny side, or just have shades/overhangs to keep out the, I'm assuming, stronger sun?

            It's a fair point that in the tropics the sun might not be as welcome inside as in the more northern latitudes, and that it's angled much more vertically further lessening the usefulness of anything on a vertical window surface.
            BR I still think it's an interesting idea that has potential.
      • Also interesting... If it is indeed, 2.5 watts, that's 1/400 of a killowat. If your window generates that for an hour, you get 1/400th of of a kilowatt-hour. At 10 cents per kWH, you earn roughly 1/40th of a cent worth of electricity per hour. Even if you get 8 good hours out of the thing a day, it takes 5 days to generate a penny worth of electricity...
        • by Moekandu (300763)

          Ya know, I think they're selling this all wrong.

          They should pitch it as a window coating that has a far better thermal performance than triple pane windows, does not require replacing your existing windows and costs a fraction of said replacement.

          Oh yeah, and it will charge your cellphone too. With a lot of windows, a bunch of cell phones.

      • by timeOday (582209)
        I would like this on the windshield of my car to power a little fan to stop it from getting so hot when I park in the sun.
        • They actually already make these. They're designed to fit on your window. You put this thing on the top of the window, and roll up the window until it's snug. The solar panels run a little fan that vents air out of the car, and a hole in the thing lets fresh air in. Whether this is actually better at cooling the car than just leaving the windows cracked is up for discussion...
        • I think car windows are an ideal application of this technology: lots of people want them tinted anyway, so now they can get that and a solar battery charger all at once!

          I just wonder if this stuff can be stretched, since car windows tend to be curved in multiple dimensions.

          • by kenh (9056)

            Cars generate bucket-loads of excess, unused electricity - what would you really gain from gluing this to your car windows? You'd be better served by carrying a battery pack and charging it in your car while you drive IMHO...

            • Car batteries discharge if the car isn't driven regularly, so people have to hook them up to trickle chargers. This would build a trickle charger into the window tint.

              Besides, its no more impractical than it would be on a house, anyway!

    • by amorsen (7485) <benny+slashdot@amorsen.dk> on Wednesday October 05, 2011 @04:26PM (#37617042)

      Actually it is dead easy these days. You buy an inverter which plugs into any socket. It doesn't support "island mode", so if the grid power fails, the solar power goes out too.

      They are not universally legal, so check the local laws. They are about as safe as anything gets when electricity is involved.

    • by Dzimas (547818)
      This is low voltage stuff - you're not going to be tying it into the grid. Trouble is, I can't really see this being of any use in the real world, unless you happen to live in an off-grid mansion with massive south-facing windows and don't mind green opaque strips blocking the view. It makes more sense to mount a conventional panel with manual tracking that can be adjusted throughout the year and receives sunlight 24 hours a day. A simply charge controller, lead acid battery or two and an inverter can provi
    • by Macgrrl (762836)

      I grew up in a small coutnry town where my father was one of the few local electrical contractors and was also a volunteer ambulance man. Based on some of the stories he used to tell me, people as a general rule don't show electricity nearly enough respect.

      I have this theory, that because people can see water leaking, they don't think twice about calling a plumber. But because they can't see electricity leaking it doesn't occur to them to call an electrician before they tinker with things they really don't

    • by iamhassi (659463)

      An average person could go to the store, buy some of this, and then bring it home and install it themselves

      Only if the average person happens to also be an electrician, or at least someone knowledgeable enough to plug a small power plant into their house's electrical system without ending up a "Dumbass Killed Tonight In Apparent Electrical Fire" headline on their local news.

      then they'll also have to sell a idiot-proof-plug-into-house-electrical-system kit.

    • by iamhassi (659463)
      It's also worthless: [itworld.com]
      "Aoyagi said a square meter of the material can generate about 5 volts at 7 watts under peak conditions"

      7 watts per square meter? 1 kwh (1000 watts a hour) costs roughly 10 cents. It'd take 142 hours for this thing to make 1000 watts, almost 18 days assuming 8 hours per day are "peak conditions" (unlikely). Unless these panels are under $1 per square meter it'd be better just to keep paying the electric company since it'd take 6 months just to save $1 on your electric bill.

      Als
    • At ~7W peak, I doubt you'll be feeding this back into your house's electrical system...

  • "The film blocks or absorbs about 80 percent of visible light and over 90 percent of infrared light, so it also acts as a sunshade"

    Thats pretty dark. Now you don't have to live in the basement

    • If you want to block 80 percent of visible light, why exactly did you have a window installed there in the first place? Just asking. Wouldn't be doing my job if I didn't ask...
      • by Tumbleweed (3706) *

        If you want to block 80 percent of visible light, why exactly did you have a window installed there in the first place? Just asking. Wouldn't be doing my job if I didn't ask...

        Yeah, most people live in places where they decided where the windows would be installed.

      • I'd love that on the west windows of my home. Odds are high I'd probably save more in cooling costs during the summer than I would in generating electricity. Come to think of it, I should really just install window tinting on those windows, how it is that I've never thought of this before is a mystery to me.

      • by Leebert (1694) *

        Aside from what others said, windows are often demanded by building code for emergency egress purposes.

    • by JMJimmy (2036122)

      Great for hot climates not so much for cold ones. But 5v 7w for a metre of the product? Might be able to power the lights in your house... but then of course you're blocking the natural light to use artificial light? The only application I can see that would make this practical would be tinting on a car... but I think 80% light blocking is too high for many regulated areas.

      • by SomePgmr (2021234)
        Well if you're generating that power and keeping your AC from kicking on, you could be looking at a win.
    • by raygundan (16760)

      We have shade screens that block 90% of the visible light coming into our house, and surprisingly, it doesn't look dark at all. (But it cut a HUGE chunk off our utility bills.)

    • by dgatwood (11270)

      Seriously. It blocks as much light as putting up a full blown solar panel that covers 80% of my window, but only produces a fourth as much power.

      So let's do the math. A typical solar panel has anywhere from 6% to 20% efficiency. Let's generously assume that this is 20% of the efficiency of a fairly good one, so... sat 4% efficient. 4% of the energy from the sun turns into power.

      Now sunlight is about 93 lumens per watt. CFLs only produce about 75 lumens per watt. So even if you had 100% efficient captu

    • by roc97007 (608802)

      That's interesting. You can actually see through my current solar array, if you squint a little. It's not completely opaque. And it actually produces 100% of the power of a solar array, not just 20% as does this film.

  • by ArsenneLupin (766289) on Wednesday October 05, 2011 @04:18PM (#37616940)
    ... who misread this as "Film turns Windows Into Solaris"...
  • by roc97007 (608802) on Wednesday October 05, 2011 @04:19PM (#37616962) Journal

    > 'An average person could go to the store, buy some of this, and then bring it home and install it themselves,'

    This is really a selling feature? Anyone can go to amazon.com, buy any one of a number of solar panel kits, get it delivered to their home, and install it themselves, with the panels inclined correctly to maximize exposure to the sun (unlikely using existing windows, which have different design considerations) and get the full output of a solar panel, not just 20%, and never have to leave their home. (Speaking from personal experience.)

    Mind you, it might be interesting to build a house designed to maximize the use of the technology, for instance, big skylights that are also solar panels. But a film for existing windows? There are better solutions.

    • I dunno... anything that increases the electricity producing square area has to be good, even if that area is often in the shade. As long as this stuff is cheap, I don't really see a down side.
      • by roc97007 (608802)

        I'm not arguing against the product, I'm arguing against the contention that it makes the product easy for mechanically-stupid people to set up a solar power system. In reality, the panels are the easy part. Scroll up to my longer article in this same thread.

    • by gknoy (899301)

      It's easier to install in your house (or apartment) windows than something which requires you to climb up on your roof.

      • by roc97007 (608802)

        Perhaps, but again, the panels are such a small part of the total amount of work that it's like arguing over the kind of hubcaps you'd put on a car you're building by hand. (*There's* our car analogy!) Scroll up to my longer article in the same thread for more information.

        Caveat: I'm not an expert, but I have installed a solar power system in my home.

    • by kenh (9056)

      20% as efficient as "conventional" solar panels, cost 1/2 as much - let's see, that works out to 2.5x more expensive than a conventional solar panel per unit of power. In other words, it takes 5 meters of this film to generate the same amount of power as 1 meter of "conventional" solar panels would generate...

    • by AmiMoJo (196126)

      Most panels installed on buildings do not track the sun, they are fixed. Installing panels means either getting up on the roof or losing some of your garden. If I could cover my south facing windows with these things and save some money on my electricity bill I'd definitely want to do it.

  • Return on investment (Score:4, Interesting)

    by ickleberry (864871) <web@pineapple.vg> on Wednesday October 05, 2011 @04:20PM (#37616968) Homepage
    Normal solar panel takes 10-15 years to pay for itself. If it only produces 20% of a normal panel it won't be worth it unless it costs about 20% of a normal panel
    • by MrTester (860336)
      With normal solar panels you have to pay someone nearly as much as they cost to install them. These you can install yourself. That can cut the true total cost in half right there.
      TFA also states that it takes less sunlight to power these than traditional cells, so while they are less efficient, they will generate power for more of the day and on more days.
    • by goffster (1104287)

      The only savings I could see were if the windows were in full sun and caused your place
      to heat up in summer. So the film might save some more in terms of cooling bills.

      • by rsborg (111459)

        The only savings I could see were if the windows were in full sun and caused your place
        to heat up in summer. So the film might save some more in terms of cooling bills.

        Even roof-mounted photovoltaic cells reduce summer heat... think about it, all that energy hitting your roof, previously converting into mostly heat + some reflected light, replaced by photovoltaics that now convert mostly into electricity and some heat. With a much higher efficiency rate and larger surface area, the roof-mounted ones may "cool" your house better than the window ones do.

        Nowadays, most new houses are outfitted with Low-E or Super-Low-E (ie, argon sandwich) glass that insulates pretty well.

    • I could see them being used in high end cars so that they never have the battery die. There are probably other instances where durable portable solar panels are desired. This would spur the R&D needed to bring the cost down until they would be used in house windows.
    • by roc97007 (608802)

      Ok hang on.

      I'm not a big fan of solar power, I think solar solutions are *way* oversold, but there are cases where they pay for themselves immediately.

      I had an issue where a new building on my property needed power. I had the city come out and mark where all the utilities were, so I could trench it myself and only have to hire out running the actual electrical and wiring it into the panel. (Which I could also do, but I'm not licensed so it'd put me in a legal grey area...)

      So I pick my path, and start digg

    • Normal panels are typically less than 20% efficient, so if these panels are only 20% of that then these panels are less than 4% efficient. - A lot of work for not much power.
    • by kenh (9056)

      No, it will just take 50-75 years to pay for itself... But I'm sure, with adequate funding from the US Gov't 3M will get that cut in half!

    • by dbIII (701233) on Wednesday October 05, 2011 @10:20PM (#37621412)
      The numbers are going to vary depending on how much grid electricity costs where you are, how much electricity you use, how much sun you get, which panels you use, how much 12V DC stuff you run, how much you run through an inverter and which inverter you have. I probably left a few things out - batteries for one thing but not all installations have them.
      Since reality is so hard to pin down you have to ask yourself where the confidence of the above post comes from. Is it ignorance and just parroting some specific case? Or is some petty little agenda being pushed to put those greasy engineers and smelly hippies in their place as mere consumers instead of rocking the boat? Either way the above poster IMHO deserves contempt.
      Two decades ago some solar panels in the right place paid for themselves on installation if they cost less than getting a line in from the grid. It's not just about being green.
  • Come down from what level? No price is mentioned. No date is mentioned when the product will be delivered.

    To keep a short story short: Come back once the vapor has desublimated.
    • by kenh (9056)

      Half the price of conventional panels - we're using natural constants, not actual values.

  • ...Coming to a theater near you! Rated NC-17 for violence and disturbing sexual imagery.

  • 80% less for only half the price? I'm sold! ...wait, wut?

  • The payback on normal solar panels is already in the 10-15+ year category for most installs. This tech costs 150% more on an output basis, so 25-40 year ROI? of windows are also far more prone to being broken then a solar panel installed on your roof hmmm think I will give this one a pass.
  • Combining Larry Elson with Steve Ballmer would form s material that could rend the very substance of space-time itself!!! Stop this madness before the universe is destroyed!!! There are some things that mere mortals should not even contemplate!!!
  • Paragraph 2 says: "still allows for high visibility."

    Paragraph 6 says: "The film blocks or absorbs about 80 percent of visible light"

    I am not an engineer - but can you actually prevent 80 % of visible light from getting through and really claim there is "high visibility" ?

    • I seem to recall that people tint their car windows to a comparable level in California, to it's at least good enough for that.
    • Paragraph 2 says: "still allows for high visibility."

      Paragraph 6 says: "The film blocks or absorbs about 80 percent of visible light"

      I am not an engineer - but can you actually prevent 80 % of visible light from getting through and really claim there is "high visibility" ?

      Indeed you can. In order to see clearly, humans need only a fraction of the visible light of a typical sunny day. During the day, your pupils are contracted, allowing relatively little of the available light to hit your retinas; you would be blinded by the glare if your pupils allowed all available light in. Blocking eighty percent of the light on a clear day at noon still leaves a lot of light, more than enough to see clearly with. Your pupils would simply dilate enough to compensate.

  • I heard about this and started to do the math.
    " Aoyagi said a square meter of the material can generate about 5 volts at 7 watts under peak conditions, and can operate under far less sunlight than it takes to power a conventional panel, so it will be active for more of the day."
    Picture one meter^2 that is not a small area people.
    Next under peak conditions?
    Peak conditions means point south if you are in the northern hemisphere and at an angle that is equal to your latitude. Most windows are vertical so unle

  • I've invented a solar panel that's 20% the size of a traditional solar panel, produces 20% of the power of a traditional solar panel, and I'm selling it at half the price of a traditional solar panel!

    -

  • this stuff would be perfect as a contingency to leaving your lights on... let the car sit for a while and it'll charge the battery enough to start the engine.

  • ... I'm working on a way to get my dog's nose to apply this. I'll be rich!

  • So.

    A link to an article about windows without any pictures.

    As a homeowner, I need to know how much light this will block, how much heat this will block. I need to know how the color and "texture" of the light will change.

    Upholstery is expensive.

    Flooring and carpeting are expensive. Wall coverings and window treatments are expensive.

    Is the transparency good enough not to significantly impair a view for which I have paid a great deal of money?

  • Apart from a few special cases, this going to be mostly useless for well designed houses - main windows facing the equator with a small verandah.

    In summer - when the sun is strong - you dont want to sun to be hitting your windows as it will cause unwanted heating. The small verandah blocks this because of the high elevation of the sun.
    In winter - when the sun is weak - you want as much light into the house as possible to supplement heating. The low elevation of the sun gets past the verandah, but if the s

  • This stuff absorbs 80% of the visible light that hits your window. That might be fine in places where the sun shines very intensely - it's about the same transparency and very dark sunglasses. However, I would not want this on my windows during already-dark New York winters!
  • Windows let light in, which you'd otherwise use electricity to generate. Although the film is see-through, it must reduce the amount of incoming light. I'm not an expert, but wouldn't the effectiveness of the film increase proportionately to the amount of light it absorbed without passing through? It seems like a window is not the best place to put a solar collector, even if it is easier than installing on a roof or other surfaces.
  • How exactly would the average person go to the store, get some, and install it themselves?

    Are they going to run the wire to the charge controllers? They are probably in the basement with the batteries, so as with most solar you're looking at a fairly major install. Except in this case it is on the windows so the wires are coming from every part of the house.

    How about set their battery banks up properly ? Plan them out for winter vs summer in terms of sun time per day.

    How about grid-tie ? Otherwise you're st
  • Although the product only generates about 20% of the electricity of a traditional solar panel, it will cost about half as much, is much easier to install, and takes up no additional space.

    This guy has invented a film that takes up no additional space — it's two-dimensional! It must be horribly dangerous to install, imagine the paper cuts. Sinclair Molecule Chain, eat your heart out.

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