Topic: Window blind solar panels - page 2. (Read 3686 times)

No one said Co2 is poisonous or toxic. Just a higher concentration than normal reflects heat energy that is usually radiated back to space. Thus skewing our avg temps ever so slightly upwards that a) some can contest but, b) can be seen long term on polar ice caps,  coral on the great barrier reef and some anomalies in weather systems. Not saying people are dropping dead, or that it's 1000 degrees. But the accumulation of CO2 (and other industrial output with similar affects) from the US industrial age through China's present day consumption of coal is enough to move the needle slightly upwards every year and the accumulated affects are becoming more visible of late. If we go into a prolonged Ice Age in 25000 years, I recant my statement. You can thaw me out from Alcor and say "I told you so".

To the rest of you following this warped thread: My technical take on the "energy windows" is unfortunately posted between this kerfuffle between MachineZero and smutboy420 about anthropogenic GHGs. So it appears I am engaged in that debate. I am not and won't waste the time in this forum. However, SB420 commits an error in logic so I'm gonna just speak to that.

The argument is of the form:
All A are B
C is not A
Therefore C is not B

For example:

All poisons are dangerous to humans
Angry bears are not poisonous
Therefore angry bears are not dangerous.

Ah yeah, but they are dangerous for other reasons. 

Yes, but one does not need to maximize electrical generation at the point of use. Just because a building has many windows does not mean they are an ideal location. The "trick" with electrical distribution is to understand that losses are proportional to the current^2*resistance. Since power is volts * current, one transmits power at extremely high voltages and lower current. A typical 765kV high tension line transmits 1000MW of power over 160km with less than 1% loss. Truly remarkable. So put the panels out in the desert/away from the city and transport it in.

We are here at 230V, so I guess it's even worse here

You're absolutely right about the solar panels on the roof. That's much better. But: this is especially designed for high buildings. Then you have many windows, but just one single roof.

Thanks for the link @brobbel. I've never seen this technology before, so I dug into it a bit and here is my 2 cents.

According to the website, the windows are sputtered (in vacuum) with a coating that directs the solar energy in from the front of the window to the edge. The solar cells are actually around the edge of the window (like a frame) and seem to be independent of the incident angle of the sun. This is kinda cool frankly and there are technologies like that about. But there are some substantial losses. As a point of reference, if you could capture 100% of the solar energy falling on a 1 square meter plate, you would collect 1kW. Typical solar panels are about 17% efficient, so 170W/m^2 is a good rule of thumb. They are quoting 25-45W/m^2 - let's give them the benefit of the doubt and call it 30W/m^2

30 Watts is fine and dandy, but now that you have that power you need to move it from the window to somewhere useful. They have two choices. Either (1) push the DC to a common inverter somewhere or (2) invert it to AC at the window location.
 
Case 1: The band gap of regular Silicon solar cells is 1.1V. Exotic higher band gap materials exist like Cadmium Telluride or Selenium at 1.74V. But this is an absolute maximum. No other higher band gap materials exist. They don't state the material in use, so let's call it 1.5V. In a DC situation they will have to stay below 12V total before they run into issues with typical building codes. Soooo... they split the "edge generators" into 8 pieces and wire them in series. Viola, it is now a 12V system. Moving 12V around at any length of distance without loss will require some seriously thick copper cables. Copper is expensive, really expensive - that's why all big industrial solar installations avoid low voltages like the plague. So DC doesn't make sense here.

Case 2: Small inverters at each window would require regular old romex type cable to transport the 120V @ a miserable .25 amps. Each window would have to be wired as a 120V receptacle, kinda prohibitive but doable. Now all the little AC legs have to be sync'd at the fuse box. Not only with each other, but also with the incoming utility. This is a problem, well solved, but adds another $1,000 box at the breaker panel.

Biggest short coming - how many 120V .25A windows do you plan on having in the house. Sixty of these windows would be 15A - just a single circuit breakers' worth of power. I think putting some plain old vanilla solar panels on the roof is a better solution. But hey, like the saying says, maybe we shouldn't live in glass houses. 

looks like it could be an ugly setup.. power cables from each window to a central inverter or battery bank. or an inverter at each window maybe that you plug things into. iow cables everywhere.

The powerwindow is already placed as pilot project in the Netherlands, and the second pilot is coming soon. Efficiency 50% of normal panels, price 200% of normal panels (but this price is high because there are only a few windows made).

The kickstartproject I don't know: AFAIK there is no pilot yet.

Very cool concept. But looks like vaporware. There are zero specifications, white papers, stats, nothing...

That has to be done, it's just a kickstarter project.

This is already done:
http://www.physee.eu/powerwindow

Those SolarGaps is a great idea imo and I'm glad they already have raised $66,836, just in 6 days.

But I doubt it's possible to mine BTC with those. As they state in the ad video, if you'd cover 2 windows, 3 square meters, with SolarGaps you'll get up to 300 Wh. Since you'll need over 1,000Wx24h= 24,000 Wh per day to run jsut one miner, it's clear that you'll never get that from SolarGaps.

Yes Carbon is very good for plants, fact. However it is a "green house gas" and therefore can attribute in part to rising average temps globally, which can lead to melting icecaps, higher sea levels and erratic weather conditions.
So great for the plants inland, bad for the plants by the coastlines. Maybe good for the seaweed and algae that have more room.

Never researched enough, but always learning.

I agree on the fertilizer and antibiotics running off into water supplies and creating cascading effects for which we won't fully know the repercussions for decades or centuries.

Apparently a reporter who got a preproduction model said they sent a very inefficient inverter which wasn't the one it would ship with. He said why bother allowing him to test and review if it wasn't the optimal setup.

There are also other issues with the setup, such as the window frame itself casting a shadow on parts of the blind panels. They said optimal configuration is an outside window mount, which is weird and will add to install costs.

Another problem is that the blind slats need to be faced at the optimal angle to the sun. It would be pretty annoying to go around the house everyday and position the slats of every blind on the southern facing side to the right angle.  I tend to do that with plain old blinds during the height of winter and summer to preserve heat or reduce greenhouse heating. But, that's usually just fully closing the blinds.

It would be nice if they were motorized and knew the time of year and day and followed the sun with the opening and closing of the slats to achieve maximum capture.

well that is really nice to have, but still the problem with solar panels isn't only about space, but about cost, if this things maintainthe same cost per watt delivered, will be pointless again

i fell the whole solar panel thing should cost 1/10 less than now, to make it worth buying one for saving, and i bet this will cost even more then a regular panel because it's less cumbersome than a standard solar panel

Interesting idea

But it will always be more complicated to manufacturer and maintain that a standard one piece panel
Furthermore, it will likely also always be less efficient that a one piece panel due it having more edges; thus less area of conversion per area of construction and it will also not always be in the correct position to best capture the suns rays.

I think the only real way to do solar is to have roof or land mounted panels (ideally on a tracking gimbal)

Ultimately - I dream of one day being able to get my energy from an orbital solar array that could be vast enough to power the whole planet

I digress...

https://www.kickstarter.com/projects/1170840477/solargaps-smart-solar-blinds

I have a strong opinion not to solar mine as a whole unless you are a home miner and recognize that the capital outlays for the specific purpose of getting "free energy" to offset mining costs is a fallacy.
But, I am green and I have roof panels to run my entire household and am under the firm conclusion that I will ROI in about 9 years and feel better about my carbon foot print as it pertains to my household.
My mining is at locations where local power is predominately wind.

This device is probably nowhere near as efficient as roof based panels, but worthy of a discussion.