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Solar Power From Home Curtains
kaliann writes "With the push for more sustainable energy, easy DIY kits for alternative energy sources are likely to become quite popular in the coming years. We may see some big improvements in our ability to 'green up' if these photovoltaic curtains become widely available."
Actually, RMIT (a tertiary institution here in Australia) recently announced that one of their new buildings will be solar-powered thanks to the glass on the buildings. From the article: blah blah blah "with an outer skin of 16,000 sand blasted glass cells, some of which will be photovoltaic solar power collectors to help shade and power the building."
I have a window with a pretty bad shade and too thin of curtains in my room. After waking up when the sun rises instead of 10:30-ish like normal too many days in a row, I got some black rodeo fabric that lets absolutely no light through and VHB taped it to the wooden frame around my window. Now it's totally black but I leave it on all day and whenever I need to open my window, that fabric feels about 100 degrees and the air trapped behind it is about the same. And that's with my shade closed! If I left it open, black fabric alone could absorb a ton of heat energy. So I think solar curtains would work great.
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I think there is a misunderstanding about the usage of the word "curtain", possibly even by the author of the article. No where in the article does the researcher who is working on this imply that they would be curtains in the normal sense. I think they are just flexible, fabric solar panels. Because they catch the light, they can be called, "curtains".
The panels turn transparent when they come in contact with water, so it's mainly for when it's raining (I suppose there are other, far less peaceful circumstances in which water can hit them). Otherwise they're translucent.
And, moving right along, look at the growth of things like Maker Faires. Or of Make, itself. Plenty of people are doing just this sort of thing.
I could go into waaaay more detail on this but frankly, afaic the store locator on either of those sites says it all. No. You are wrong. Plenty of people do just this kind of thing all across the developed and developing world. Evidently they just don't hang out with you.
It's all about the information. And what we do with it.
Actually I think they will save more power with the curtains open than closed.
I'm shooting from the hip here but looking at the picture I expect there's a serious flaw here. The Curtains look black so they are absorbing a lot of light energy. We know they are highly inefficient. So they mainly heat your house.
SO in summer time you will pay more in cooling costs than you gain in electricity. Either that or be warmer. Logically you want the drapes outside where they would be amiently cooled.
Now if you draw the blinds and thus it gets darker and you need to turn on a light well. So much for any gains.
Finally most houses are designed to have their windows shaded more or have an oblique incidence in summer time. Thus during the time of maximum sun, and warmth you get the least electricity.
In winter time when the solar flux is less and there will be fewer hours of daylight the direction of incidence will be better. But chances are you'd like the light.
The drapes have no thermal mass so they act like the worst kind of traum wall where they heat up and cool down quickly. No thermal damping.
Seems like archecturally this is a bad idea from the get go regardless of how the solar fabric technology improves. Maybe in northern canada or something it makes sense.
Some drink at the fountain of knowledge. Others just gargle.
If you are trying to cool with curtains you want white curtains.
Some drink at the fountain of knowledge. Others just gargle.
The problem I see is mostly that somebody needs to start manufacturing such turbines, complete with standard output to a battery
No, the problem is there's an incredibly tiny amount of energy in the water from a toilet flush falling 30 feet.
energy joules = m(kg)*h(m)*g(9.8 m/s)
= (3.8*3) * 30/3.28 * 9.8
= 1021 joules.
a kilowatt hour is 3,600,000 joules. so we're talking about 1021/3600000, or .00028 kilowatt hours. My power costs about .10/kilowatt hour, so one flush is equal to $0.000028. If you flush 4 times a day for a year, that's $.04 of electricity. (and this is assuming you're able to capture ALL of the energy, which you can't do, and the water falls 30 feet, which isn't happening in anyones home anyway.
AccountKiller
While this is true for batteries, I do not believe that batteries will power the future electric cars. Do a wikipedia search for Supercapacitors to see what is on the horizon. They are not yet perfect but MIT has demonstrated capacitors that offer 1/4 of the storage capacity of Li-Ion batteries.
There are many advantages to using capacitors in place of batteries - mainly due the the greatly reduced internal resistance. First, the charge time is reduced to under 10min. Second, when used in a hybrid vehicle, one does not encounter the loss associated with "charging" the batteries so regenerated power can actually be reused. Thirdly, they will not go bad like batteries. They are typically rated for ~10000 charge cycles. There are also many other reasons why these new capacitors are desirable - just read the wikipedia link.
Nasch already took care of some of your illogical arguments... but you've made other assumptions that are just plain wrong or at best outdated.
20% efficiency on a solar panel is not uncommon. In fact, you can buy 28% efficient solar panels (as long as you don't live in the US *grumble*). Over their lifetime, of course that rate is going to fall, but it will still remain a bit above 20%.
Given time, that efficiency is only going to improve. Both of these factors right there shoot your 600M^2 theory to shit.
Using you and your family as an example, your average 1.4KW usage could be dramatically reduced without impacting your quality of life in an appreciable manner. I know this is so because I've done it myself. It takes some will power and awareness of what power you are actually using, but it can be done fairly painlessly. You can start by replacing your incandescent bulbs with CFL or better yet with LEDs. One of the largest single power draw in a home is from all the light bulbs. Reducing that can cut your monthly average quite a bit.
You need to turn off stuff you aren't using. Putting things into standby is not turning them off... in fact, many appliances and electronic gadgets don't even HAVE an off switch, they go into standby. So that means you have to unplug them. That's a pain in the ass. However, a simple solution to this is to plug everything you use for a particular activity into a power strip... when you're done, turn the power strip off. This overcomes the leeching power used by wall-warts, as well as gadgets and electronics that go into standby mode. Yes, you may have to wait a few seconds longer for something to power up, but it's not a huge deal.
Another big energy saver is to replace your windows. If you have contractor grade windows in your house, you are leaking energy like a sieve. Replacing your windows with high quality double or triple paned, krypton filled windows with insulated frames will save you a TON of money and energy for cooling and heating.
Do you have an ancient refrigerator? If so, it's probably drawing 2 to 3 times the amount of energy a modern refrigerator uses (or more if it's REALLY old). Might be worth it to replace it.
Do you leave your computer on at night? Turn it off, or at least put it in standby. My system, at idle, draws about 600w, when it's in standby it drops to about 30w. That's a HUGE savings on a month or yearly basis. If you're on Slashdot, chances are you've got multiple computers - I think you see where that's going. If you're using an old computer as a Linux router or something we are all fond of doing - stop. Old computers are incredible power hogs. A cheap wireless router that you can load new firmware onto will suck a fraction of the power, produce a fraction of the heat and noise. It's nice to think you're recycling your computers, but it's costing you more than they are worth in power per year, for sure.
There's lots of things you can do to reduce your power consumption. You can take your 1.4kw to 800kw fairly easily I suspect. That almost halves your 600M^2, coupled with the fact that you can buy efficient PV panels, now you only need about 200M^2. The average house has that much roof space that's likely suitable.
Even if you don't, as long as you are offsetting some of your power needs, it goes a long way to helping bring about a more energy efficient future.
Is it going to be uncomfortable? Probably a bit, but not cripplingly so, and once the "new" way sets in, it will seem silly that we didn't do it a long time ago.
why is it people are so ready to believe every so called green product? this curtain idea is so obviously flawed it's amazing anyone is buying it as real in the first place.
for a start, you do realise this is about the worst way to collect solar power? 2nd, claiming it can produce 70% of our power need is a total lie - base load people, learn what it is.
If you mod me down, I will become more powerful than you can imagine....
Study some heat transfer principles. Depending on their reflectivity, these curtains may cause the roof to absorb MORE heat than the roofing does.
Ideally, solar installations for home use will not transfer heat directly into the house. A curtain laying directly on the roofing surface will absorb some light and create some electricity. However, light and heat that is not reflected will absorb and the greater part will transfer through to the house a large amount of heat. A smaller portion will radiate from the house.
Solar panels are typicaly elevated above the house. The air gap allows the panels to be cooled by airflow.
The actual news here is that they can create solar fabric. I'm sure they can design a roofing system that will use the material to generate electricity while the system maintains an air and water seal and reflectivity of the largest part of the sun's energy.
TANSTAAFL GIGO Acronyms to live by!
People don't even do it when it's a trivially easy task that they perform regularily anyway.
Take modern light-sources as opposed to incandescent ones. A typical bulb migth live for 2000 hours, cost $1, and consume 60W. A modern replacement (that screws directly into the same socket) migth live for 8000 hours, cost $10 and consume 15W.
At current electricity-prices it SHOULD be a complete no-brainer.
$1/2 + 1000 * 0.06 * $0.15 = $9 (for each 1000 hours of light)
$10/8 + 1000 * 0.015 * $0.15 = $3.50 (for each 1000 hours of light)
It's one third the price, basically.
It's also more environmentally friendly (ok, so you DO need to return the used bulbs responsibly), creates less extra heat in the summer, and thus reduces your AC-bill somewhat.
And it literally costs you NO time at all. When the old bulb burns out you need to put in a new one ANYWAY. And putting in a modern one instead of an old-fashioned one is a similar task, one ain't harder than the other.
Nevertheless, hundreds of millions of old-fashioned bulbs burn in USA today. It's sad, really.
Most people don't even replace their lightbulbs with more energy-efficient ones. And that's a 1-minute job. (zero-extra if you do it the next time the bulb burns out anyway)
Also, you're ignoring the PAYBACK time. It doesn't matter if something is easy to install if buying it costs more than it could ever earn you back. It's a loss. Doubly so if producing it costs more energy than it'll save/create.
Typical home-biking may produce 100W when it's in use. Few bikes are in use more than 3 hours/week. So you'd produce 0.3Kwh/week, or about 5 cent worth. In a year that adds up to $2.50, in 4 years it adds up to $10. Can you add the needed generator, cable, and infrastructure for receiving the power into the grid for $10 ?
The door-stopper is even sillier. A typical door weighs what, 10kg ? It moves how quickly before being stopped, 2m/s ? (about 4mph) That is an energy of 1/2*10*2^2 = 20J then.
You would need to slam the door 50 times a day, every day, for 10 years to create one single Kwh. Worth $0.15
Do the stuff that makes SENSE. Get a energy-efficient car. Change the windows in your house if they're old and poor. Have a well-insulated house. Use modern lightbulbs. Consider solar-water-heating if you live somewhere where it's warm and you shower a lot (these two often go together, for obvious reasons)
Drop the stuff that's just useless gimmicks.
You can't use glycol in a water heating system! The risk of the heat exchanger developing a leak and poisoning people is way too great. There's no way that would meet code in any civilized place. That's why you have to use a drainback system, none of the non-toxic heat exchange fluids that are affordable can handle really cold temperatures (-15F is a rare but not unheard of low here in the Great Lakes region).
There are 4 boxes to use in the defense of liberty: soap, ballot, jury, ammo. Use in that order. Starting now.