Pour-In-Place Solar Cells

ianchaos writes: "According to an article in New Scientist, solar cells that 'self assemble' from a liquid have been developed by scientists at the University of Cambridge. The breakthrough could make it cheap and easy to cover large areas, like roofs, with efficient, ultra-thin solar cell coatings. Now they just need to try coating clothes with the stuff to make the wearables more viable."

bout time

[PBCODER]

Oh yah Baby... FP I've been searching for patents that show the comstruction method of cells for a while now to build my own. Maybe we dont need to buil them just pour them. I live in FL and it always erks me to see so much free power all over and we can't use it because of cost factors.

Re:bout time

[Procrasti]

so much free power all over and we can't use it because of cost factors

that doesn't really make sense....

Solar Cells

[veinard]

To their defence, though the application technique sucks, it does have a lot of implications. An organic solar cell with 34% efficiency is really amazing actually. The solar cells used in the space program are expensive thin film gallium-arsenide that are about 24% efficient. The solar cells that we can go out and buy on the market are amorphous, poly-crystalline and single crystal Si cells that have efficiencies from 7%-16% or so. Even at low efficiencies of 16%, if you cover a roof with solar cells in Ca (Which is cheaper than you might imagine given all the government subsidized loans and rebates for this kind of thing), you can power all of an energy efficient house during the day, as well as sell back some energy (which the utilities are required to buy) while you are at work. So yeah, you still buy energy at night, but it ends up as no net energy cost after installation. My point is, if they really mean that 34% efficiency, this has the potential to seriously reduce the power problems in most of the united states, since it would make solar viable for places in the US that are exposed to fewer days of sunlight, AND make it more affordable for all.

rant complete

Re:Solar Cells

[Prof_Dagoski]

Anyone intersted in going solar should check out this product [ovonic.com] from Unisolar [unisolar.com]. It's about the cheapest I've seen yet. If I've done the math right you could roof a decent sized house with these for about $5000.

Re:Solar Cells

[gogogo]

The article at the end said they need to raise effeciency. Perhaps the %34 efficiency is for only a narrow band of the solar spectrum.

Re:Solar Cells

[Cy Guy]

Perhaps the %34 efficiency is for only a narrow band of the solar spectrum.

That seems to be it. According to the abstract [cam.ac.uk] "these films show photovoltaic response with external quantum efficiencies of >34% near 490 nm." 490 nm is right between blue and green in the visible spectrum.

Re:Solar Cells

[brokenwndw]

Not exactly... the 34% quoted is the "external quantum efficiency" which I assume refers to the ratio of input photons to output electrons or something similar. On page 1122 of the article it reads, "The power efficiency maximum was 1.95% at 490 nm." This, naturally, doesn't really cut the mustard in comparison with silicon cells. ------------

Other research

[Myco]

I'm more impressed by some of the other research being done in this area, such as the German scientists who are developing solar fabric [newscientist.com]. Maybe solar-powered textiles will finally explain 7of9's shiny wardrobe.

Good toy, but not an important energy source.

[Acto]

With its low efficiency, this type of solar cell will have very few uses. And solar power is nearly useless as a large-scale energy source: even in the sunny southwest desert, the average power one can collect with solar power is no more than 240 watts per square meter. No matter how cheap the solar collectors are, much of the cost of solar power would take the form of batteries used to keep the energy coming while the sun isn't shining.

Re:Good toy, but not an important energy source.

[hamburger lady]

eh? 240 watta/sq. meter is a lot. either way, i believe that is on the very high end of possible energy capture, i.e. assuming a very very efficient panel.

however, A)240 W/sq m means a small roof could provide 20kW or so, way more then a regular house needs. even assuming a low efficiency, the numbers are still pretty nice.

B) you don't need batteries, just hook the system up to the power grid, and during the time you make more than you use, the power company pays you for the excess.

Re:Good toy, but not an important energy source.

[BigBlockMopar]

eh? 240 watta/sq. meter is a lot. either way, i believe that is on the very high end of possible energy capture, i.e. assuming a very very efficient panel. however, A)240 W/sq m means a small roof could provide 20kW or so, way more then a regular house needs. even assuming a low efficiency, the numbers are still pretty nice.

Yeah. And maybe 20 years or so from now when the technology moves out of the laboratory and into Home Depot, we'll see it powering peltier junction air conditioners.

Also, how do you collect the power from the solar cells? Anything capable of dumping 20kW of power would be ...troubling, since a paint-on coating isn't terrifically easy to which to make a low-resistance high-current connection. Anything less than a perfect connection to the surface would result in voltage drop due to the resistance of the connection. There would be a *lot* of heat.

B) you don't need batteries, just hook the system up to the power grid, and during the time you make more than you use, the power company pays you for the excess.

Typically, electrical demand in a city increases as the sun sets. Batteries *would* be required, and current (and horizon) technology isn't especially efficient.

20kW of power, per house, trying to be put back into the grid would mean that all the pole transformers and stuff would have to be retrofitted for it. Much of the grid in my area was installed over 40 years ago, and is unlikely to be changed in the near future - it's built to last.

Finally, household power is 60Hz (in North America) AC. Syncing the inverter to convert the DC from the solar cells into AC with the grid is a non-trivial exercise. If the power from the grid and the power from the inverter are off by even one degree in phase, bizarre problems which would look like a lagging load (power factor) issue will ensue. Very nasty.

I see something like this as, in the future, being a great way to power air conditioners on sunny days (but what about hot and cloudy days) but beyond that, I think it's a neat idea that will remain essentially impractical.

Spinning buildings...

[WebGuyCS]

They then poured some of the mixture onto a spinning glass sheet coated with an alloy electrode.

I want to see them spin the buildings around to put this coating on them. That would be way cool!

Honestly, is this really practical? I'm not sure this qualifies as a breakthough quite yet. Call me when then create a high effeciency solar cell that can be poured out of a bucket onto the roof on a jobsite.

Re:Spinning buildings...

[Skyfire]

The breakthrough is that they found a method of getting fairly decent efficiency with organic materials, not so much the method of application.

Re:Spinning buildings...

[WebGuyCS]

I guess I need to work on my sarcasm. ;-)

I was essentially trying to make the same point as you. Somebody made a huge leap from this article to "The breakthrough could make it cheap and easy to cover large areas, like roofs, with efficient, ultra-thin solar cell coatings." It doesn't sound like the application method is cheap or easy. Rooftop solar cells are still a long way off.

Phoenix

[TWX_the_Linux_Zealot]

I hope that these cells become viable in the next few years, for as high as Arizona Public Service is with its electric service, I'd be more than happy to install something like this. It would pay for itself so quickly in the summer (when we have rain 5 days out of 90) that my electric bill could drop from $140 to $50 or somesuch.

Can't be 34% efficient

[btempleton]

They said that they needed to work to improve the efficiency to make it viable, and that is simply not something that would be true if it were 34%. There's very little improvement even possible at that level of efficiency.

However, cells that can be poured on and installed locally would be a huge boon if they can make that work.

Re:Can't be 34% efficient

[kaltan]

Good point, but they said that it peaked at 34% percent. I think they mean by this that on some spots of their pannel they got good efficiency and on others far lower.

Improving efficiency would mean that the whole solar pannel works on efficiency levels close to 34%