Slashdot Mirror

← Back to Stories (view on slashdot.org)

Solar Windows Could Help Power Buildings

Posted by Soulskill on from the people-in-solar-houses-shouldn't-throw-stones dept.

Lucas123 writes: Several companies are now beginning to roll out translucent photovoltaic films or solar cells embedded in windows that can supplement a significant amount of energy in the buildings where they're used. SolarWindow Technologies, for example, is preparing to launch a transparent product made with organic PVs, while another company, Solaria, is cutting solar cells into thin strips and embedding them in windows. Both companies admit their products can't produce the 20% efficiency ratings of today's best rooftop solar panels, but they say that's not their objective. Instead, the companies are looking to take advantage of millions of skyscraper windows that today are simply unused real estate for renewable energy. One company is aiming at supplementing 20% to 30% of a skyscrapers power requirements. Meanwhile, universities are also jumping into the solar window arena. Oxford University has spun off a PV window company that produces semi-transparent solar cells made of semi-transparent perovskite oxide that has achieved a 20% solar energy efficiency.

2 of 89 comments (clear)

  1. Re:I'm a genius. by Anonymous Coward · · Score: 3, Interesting

    I know that you're joking, but I'm going to analyse your post anyway ;)

    These are said to have barely over 20% efficiency at the moment. I can't find where it says how much light they block, so I'm just going to pull a number from thin air and say 50%. This means that your first layer works at 20% efficiency and functions as a window; the second layer will result in 30% efficiency and be a bit too dark to be a good window (and cost twice as much too); 3 layers would be 35% efficient, triple the price, and basically unusable as windows; 5 would be 38.65% efficient, ludicrously expensive, and usable only on a tiny patch on the roof when the whole point was to sacrifice some efficiency in order to be able to use the surface area on the side of the buildings.

    But I like your way of thinking , especially since it raises the question of what would happen if you go past 5 layers and start generating energy from nowhere :)

  2. This is kind of a trope by Anonymous Coward · · Score: 4, Interesting

    Cities don't have anywhere near the solar density necessary to make a dent in their consumption. There's just barely enough in a neighborhood, but when you get to multi-story density, it's a hopeless gesture.

    It gets even worse when you use thin-films which have waaaay less efficiency than crystalline panels.

    And it gets even worse when you mount them on vertical surfaces like skyscraper windows.

    And it gets even worse when you have thousands of distributed pieces of small electronics that all must be maintained, managed and the energy combined.

    I loooove solar and I can tell you it's just NOT WORTH IT. Make a big field outside the city and send the power in. Everything is a waste of time or just for show.

    A lot of people have emotional feelings like, "but it's all just going to waste in the city." But use your head: It's all just going to waste out in the desert too. So be wise and put efficient, dense PV where there's lots of sun. Don't put inefficient PV distributed around where there's weak sun.

    It's like trying to write a letter with twenty light pencils. Just use one dark pencil.