
UCLA's new transparent solar film could be game-changer - ot
http://phys.org/news/2012-08-ucla-transparent-solar-game-changer.html
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astangl
I wish I got a nickel for every one of these solar "game changer" headlines.
I'd love to believe the hype, but these wondrous lab results don't seem to
make it to the marketplace. By now we ought to have almost-free PV paint that
we could paint onto every surface, turning our roofs into almost-free PV
cells, windows that function as PV cells, etc. I don't mean to be cynical, but
is this field more prone to hype, or just gets hyped more on HN, or what?
Maybe the "game changer" hype stories ought to be tempered with some
consideration of what might impede commercial development of the idea, like
maybe why it's impractical after all.

~~~
AndrewDucker
They're happening all the time.

[http://reneweconomy.com.au/2012/solar-insights-pv-costs-
set-...](http://reneweconomy.com.au/2012/solar-insights-pv-costs-set-for-
another-30-fall-in-2012-2012) 30% fall in production costs this year, 75% over
the two previous years. PV costs are constantly dropping at very high rates.

[http://cleantechnica.com/2011/06/10/solar-power-graphs-to-
ma...](http://cleantechnica.com/2011/06/10/solar-power-graphs-to-make-you-
smile/)

~~~
marvin
Yep. Things are getting really interesting these days. Some German coal plants
have to shut down during peak solar production because they simply become
unprofitable to operate. The US has added huge import taxes on the next
generation of Chinese panels. Lots of existing solar companies are going
bankrupt because they haven't been able to adapt fast enough.

It's not just a series of pie-in-the-sky headlines. Things are changing, fast.

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jws
Thin film, transparent in visible frequencies, nanoscale wires you can't see,
harvests infrared, captures 6% of the incoming radiation, maybe 10% in 3-5
years, infrared accounts for 18% of sunlight. A good match for covering
windows where you want to block the infrared anyway.

~~~
Retric
Most windows are poorly placed to collect sunlight. Anything that's not
sloped, southern facing, and shade free is going to be a lost cause unless
this ridiculously cheap.

~~~
jws
_Most windows are poorly placed to collect sunlight_ – ok, don't use it on
most windows. Sloped isn't really important. Southern facing and shade free
is.

Vertical, southern facing isn't bad for high latitude folks. For instance, I
have my non-tracking panels at the optimum angle for this time of year at 45°N
latitude for 2.8kWhr/m^2/day[1]. If they were vertical it would only drop to
2.5kWhr/m^2/day. Going the other way, a 2 axis tracker would get
3.1kWhr/m^2/day[2]. So that is about a ±10% range for mounting options.
Vertical loses more like 40% in the summer.

[1] November is my worst month. It is cloudier than December.

[2] Trackers never work out at my scale, ~600 watts of panels on a pole mount.
It's always cheaper to just add another panel.

[3] Standalone footnote: It is an island. Grid power is not an option. This
time of year it is just running telemetry, cameras, and keeping the batteries
from freezing, but during the summer I get 6.1kWhr/m^2/day which gets me
around 3kWhr/day (woo hoo! 25¢ of electricity!) and that takes care of four
people. I choose a generator over a battery bank big enough to ride out more
than one cloudy day. It gives me redundancy if the solar/inverter system
fails.

~~~
Retric
Static solar panels at 45°N latitude only work for really remote areas or with
heavy subsidies which are much better spent in southern areas. (Even adjusting
for transmission losses.)
[http://www.nrel.gov/gis/images/eere_pv/national_photovoltaic...](http://www.nrel.gov/gis/images/eere_pv/national_photovoltaic_2012-01.jpg)

Now, as your in a remote area it's worth considering, but even if it's
minimally expensive there are still far better mounting options than vertical
which makes the discussion somewhat moot IMO. Also, full time tracing may not
be useful, but you can use a manual bracket to change the angle once in spring
/ fall and get noticeably more power. EX: ([http://www.crown-
international.co.uk/products/season-adjusta...](http://www.crown-
international.co.uk/products/season-adjustable-solar-panel-mounting-frame/))

Honestly, it's a cool idea, but space is not the problem with photovoltaics it
cost to deploy which is really the only important question.

PS: As to 25c / day, that's assuming you could get on the grid as long as it's
worth paying for it can be worth far more than that.

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mchannon
On the off chance that this technology's cost could be brought down to the
same per square meter as a conventional solar panel, it would add $35 to the
cost of each 0.5 m^2 window, plus installation, wiring, conduit, and power
converters, for a power output around 1/8 of a correctly installed commodity
solar panel (and that's assuming they're able to make their 6% number work in
the real world for 25 years). The 1/8 number comes from not only lower
efficiency but also shading losses and bad angles.

It's a neat research project but even high-rise buildings have more cost-
effective options for generating on-site solar electricity and blocking
unwanted light.

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dmritard96
The concept is nice but making it to market will still be tough. As far as
windows and that type of small scale application, I hate to be a debbie downer
but I think the cost of MPPTs (Maximum Power Point Trackers), transformers,
inverters and storage shouldn't be overlooked. Most of those components become
more cost effective with larger PV installations and 6% (or even 10% if they
actually get there) means that a few windows probably won't really bring the
scale that makes the rest of a PV system a cost effective solution. I do see
this as a cachet product though, maybe in the same way that the solar-prius
uses its solar to run fans...Hopefully the efficiency goes up and it can be
brought to market. If it really can be sprayed on then any and every surface
has potential (yuck yuck yuck).

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MojoJolo
In positive note, I was thinking this to be integrated in touch screen phones
several years from now!

Imagine using your phone, playing with it while walking in the strees and it's
charging through the solar film integrated in the screen.

~~~
robotresearcher
I looked into this because it sounded far-fetched.

The power available in sunlight in perfect conditions (at the equator at
midday, oriented perfectly, is around 1KW per square meter. Scaled down to
iPhone 5 size gives 7.22W. The iPhone charger can provide 5W.

So maybe with extremely efficient photovoltaics you might be onto something,
but unless you leave your phone flat in the sun in Ecuador over lunch, this is
probably not practical. Mine lives in my pocket.

~~~
Someone
Wild thinking: this uses infrared. Your body irradiaties infrared. So, Put it
on or in your clothing (could be the inside of your t-shirt, or even your
underwear), and you're all set :-)

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tribe
Sounds more like a game-charger to me!

