UCLA's new transparent solar film could be game-changer | Hacker News Reader

UCLA's new transparent solar film could be game-changer

phys.org

60 pointsot16 comments

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.

They're happening all the time.

http://reneweconomy.com.au/2012/solar-insights-pv-costs-set-... 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...

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.

Not sure what the "not including silicon" means in that first story. Nevertheless, these are evolutionary improvements, not the revolutionary ones implied by the hyped headlines. Don't get me wrong -- I'd love to see PV power production become prevalent. I've been waiting decades now, regularly reading stories about "paint-on" solar cells, etc., and getting frustrated at how the "paint-on" and "spray on" thing keeps getting headlines year after year, decade after decade, but somehow never becoming a product. Isn't it rational to question when the same "game changing" idea keeps making headlines, across years & decades?

> but these wondrous lab results don't seem to make it to the marketplace

However, there is a very good progress in solar energy production.

According to this chart [1], solar production in July '12 (peak month) was more than twice the producion in July '08 - 100% increase in four years.

And that's in US only, and they aren't the leaders in solar adoption - that'd be Germany and Italy, according to BP report [2]. This report also says that worldwide solar production grew almost ten-fold over the last 5 years!

So, I'd say lab results do affect the global picture already.

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[1]: http://ycharts.com/indicators/us_solar_energy_production

[2]: http://www.bp.com/extendedsectiongenericarticle.do?categoryI...

Indeed. It seems all energy "game changers" are perpetually 10 years from mass market. Not that we shouldn't keep trying, but its definitely something that can make a cynic out of you.

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.

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.

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.

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...

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...)

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.

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.

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).

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.

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.

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 :-)

Sounds more like a game-charger to me!

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