Slashdot Mirror
Solar Windows Could Help Power Buildings
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.
Semi transparatent with 20% efficitntcy. Just put 5 of these suckers, one behind the other, and you're at 100%! Imma go on Shark Tank as soon as possible and get funding for this blockbuster and file a patent today.
Are they already designed using multiple layers? I'm no photovoltaics expert, but with 20% efficiency per layer couldn't they combine 5 layers to achieve "100% efficiency" per window? Seems like with enough windows a building could theoretically get all of its power from solar - at least on sunny days.
Is that normal? Only use 20% of the available solar power? Why is it so low?
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.
Apple likes to brag about being green. Rings pretty hollow now, doesn't it?
Linux won't be so green until Microsoft's patent expires.
There's no way this is cost effective. More money down the drain.
These films are so poor on performance, you can put 3-4 real solar panels on the roof and make the same energy. They would not block sunlight from entering the building. the fact that most tall buildings are grouped together and cast shadows these windows would produce very little and would be very costly. We are not lacking good solar panels for roofs. We are lacking utilities that will let us connect to the grid our parents paid for years ago.
As the article noted, the double benefit of this system is not just the token energy it generates but the ability to better control HVAC costs by reducing the amount of heat that goes in through the windows, reducing demands on air conditioning in the summer. That being said, based on the pictures, this system is not pretty: the lines running through the translucent cells are rather annoying to look at and could be shot down by builders for the aesthetics alone. It would be better if they could deploy this as some sort of window shade that can be retracted to allow for unobstructed views (looking at the photos of the sample setup, it reminds me of the translucent shades used in a lot of newer offices), but I don't think this technology is there.
SSIA
Or we could stop designing our buildings to look like they're made out of glass...
Do not look into laser with remaining eye.
The article talks about changing all the south facing windows in the office towers. It sounds great but in the city there's usually another tall building across the street blocking the sun so there's not much point in changing all of the windows. Maybe the ones near the top that does get the sun. I could see it being of more use in less dense areas but not in city centers.
Why do people waste time on Slashdot with this stuff? Unless they are implanting little nuclear fission reactors in the windows, most of the posts here will be a bunch of whining on how nuklear kicks ass and any other attempt to do anything related to energy is stupid. They will then rant on how great the world would be under various "what if scenarios," as they shake their fists at the sky.
Any attempt to call this out will be modded down to hell, so you only get a small resistance who seem to think that wasting their time to make Slashdot a little less biased and realistic is worth it. Then you get Anon posts like this that are just a therapeutic rant for the poster (Seriously, guys, get a life and fucking "live in the now." For whatever the fuck reason, decentralized technologies have fucking blown past nuclear fission. Fucking deal with it, already.)
Allowing less heat in would be good for the summer but bad for the winter. For that, I think the windows lined with e-ink would help. The windows can be set to darken during the day in the summer and clear during the day for the winter. In the winter, when you want privacy, there's a capability to scatter the light coming through to blur the view without blocking a significant amount of the light from getting in. These windows would look nice and they could eliminate the need for blinds or curtains. Set the windows to automatically open up when someone is home and the outside temperature is within a comfortable range (and it's not raining or too windy) and you'd have a significantly more efficient home.
Most skyscrapers need AC even during the winter. Any reduction in added heat from the windows would help.
As if they don't already routinely apply much cheaper coatings specifically designed to do that.
Not everyone likes living in a basement...
Faster! Faster! Faster would be better!
What kind of toxins might be involved in the creation of these new windows, and what happens when a window breaks? Can the pane be easily recycled? How much energy does it take to produce one of these windows, and how long can we expect it to take for the window to capture a matching amount of energy?
Just curious.
Maybe we could remove all skeumorphism, transparency, bevels, borders, and gradients here in the real world as well? I propose we call this style "new metro!"
Irony: Agile development has too much intertia to be abandoned now.
Far more helpful would be to add awnings over windows like the Petronas towers have. The view is not obstructed, but high angle sun is largely never hitting the windows.
You still have to pay to have them applied. And that's the same cost for both, have you got a figure for that and the cost of both films? And one film will just cut out the heat coming in, whereas the other one does that and generates power you can use locally and cut down on your (businesses run at peak times, hence why they are peak) expensive electricity bill in the daytime.
So, above 45N, it's as useful in collecting sunlight (or better) than a solar panel placed horizontally on the ground, it's 20% efficient. And the load will be best used during the peak of solar power. So something like 100watts per square meter peak. If it only generates for four hours a day average, that's 0.4kwh each day per square meter, and a skyscraper is, what, 100m wide and 200m tall in a city block? Just one side generates 8Mwh per day. At 5c/kwh or $50 per Mwh, that's $400 a day. Every day: $146,000 a year.
How much does it cost to purchase and install that area? Done the maths?
We got rid of gradients with Windows 8
I gotta set me up a Kickstarter or something.
You still have to pay to have them applied.
if it's done at the factory on automated machinery the cost is probably pretty minimal
A nice simple drop-in application would be this, a decent but discrete battery and some lighting (maybe built around the window, maybe elsewhere). Then you have daylight during the day and free electric lighting at night. If the glass can also be switched translucent/clear that would be an added bonus, though I'm not sure if the two techs would be compatible.
And yes, I know that this would be non-optimal, but it would also be relatively cheap, simple to install and have an immediate useful function. More optimal integrated functionality can come with time.
> Remember that light energy can't be converted to electricity and also
> transmitted through the window; whatever percentage gets converted
> to electricity must be subtracted from the percentage that is transmitted.
A hot summer day...
* incoming sunlight reduced; check
* some electrical power provided for air conditioning; check
Now that's what I call win-win.
I'm not repeating myself
I'm an X window user; I'm an ex-Windows user
Because coal powered fire stations are only about 30% efficient. Your "best solar available" that you find so disappointing is half as much again as efficient.
I guess all that coal powered generation infrastructure was an illuminati conspiracy and they just made you THINK you had electricity!
You don';t have your building lying down in the factory. You have to pay to put them up where you need them. Got a cost for that? The cost per film meter coverage may be much higher, but if the film is a small fraction of the cost of installation, the increase in installation cost is not anywhere near as large.
So, again, do you have any figures for this? Or are you presuming it is not going to work then claiming it won't work?
Post hog ergo propter hoc fallacy.
I know what you mean... I remember reading headlines about this as far back as 2002...When is it ever going to actually happen?