Comments on: Vastly Improved Solar Cells Possible With Use Of New Heat-Resistant Materials

By: KennyDude

KennyDude — Sat, 11 Jan 2014 16:39:00 +0000

I’m no expert but I believe it just means that more of the energy thats wasted in heating up the solar cell is used towards electricity generation. 2nd law of thermal dynamics states the more heat you generate the less efficient the conversion of energy to useful work ( I think). So I believe this filters out the spectrum thats not convertible into one that is to get more efficiency. So for consumers it should translate into better efficiency. I wish they stated the efficiency numbers after using the ceramic coating.

By: Ronald Brakels

Ronald Brakels — Mon, 21 Oct 2013 02:58:00 +0000

Well, I’ll give you a commonly used extrapolation procedure and you can use it to see for yourself how much difference 200 degrees makes. The Larson-Miller parameter is:

T(C + log tr)

Where T is the temperature in Kelvin. C is a constant which is usually about 20 and tr is the rupture lifetime in hours (How long before things go bad.) Note that this may not be appropriate for the material mentioned in the article, this is for demonstration purposes only.

By: Sean

Sean — Mon, 21 Oct 2013 01:29:00 +0000

Let’s not be too smug when someone is asking from ignorance. You were once ignorant.

By: JamesWimberley

JamesWimberley — Mon, 21 Oct 2013 01:13:00 +0000

Thanks, that makes sense. and so does your scepticism. CPV is just too complicated to pay at scale.

If you could deposit a *transparent* layer of the emitter on top of a silicon cell, that might work, But the photos are of a layer micrometers thick, not nanometers. The perovskite cells (330nm= 0.3 µm) reported on earlier on this site are semi-transparent so the compound cell looks possible. See phys.org/news/2013-09-team-physicists-perovskite-conventional-solar.html

By: JamesWimberley

JamesWimberley — Mon, 21 Oct 2013 00:58:00 +0000

You mean 1200 deg C isn’t enough to ensure long-term stability at 60 C, and 1400 C is?

By: Shiggity

Shiggity — Sun, 20 Oct 2013 20:51:00 +0000

I’ve seen a couple systems being developed that incorporate concentrating solar with natural gas. They both can share turbine resources and while the sun is shining they turn off the gas and it also helps a lot during peak times.

http://inhabitat.com/florida-launches-the-worlds-first-hybrid-solar-energy-plant/

This technology would directly benefit a system like that.

By: Gerald Katz

Gerald Katz — Sun, 20 Oct 2013 18:50:00 +0000

Flat plate silicon cells proven long life ( I have modules made in 1980 that still work fine) Modules now getting so affordable that some new homes have them integrsted with the roof at a cost not much more than high end stsndard roofing. Utility systems with tracking pv provides maybe 30% more energy, if there are going to use concentrating collectors go thermal. Turbines produce Ac no need for inverters, thermal can be stored. Low temp solar thermal organic rankine turbines can also be run on with industrial waste heat or combined with geothermal energy for 24/7 with afternoon peaking. High temp concentrating towers and mirror fields have been able to store enough energy to run 24/7 and the high temperature energy might also be used to power a wide variety of chemical and industrial processes.

By: Omega Centauri

Omega Centauri — Sun, 20 Oct 2013 18:12:00 +0000

I can only imagine this in some sort of CPV context, where the light is focused of this new special material, and the emitted infrared is then directed to the (much cooler) PV cell. Hard to imagine it being practical in any way -CPV is already dying because of cheap panels.

By: Bill Kalahurka

Bill Kalahurka — Sun, 20 Oct 2013 18:11:00 +0000

There is a huge misunderstanding here. A thermophotovoltaic device is very different from a PV cell. All I know is what I’ve read on Wikipedia, but in a tpv device, the immediate source of photons is not the sun, but an “emitter” which has the property that it releases photons of a desirable wavelength, whenever it is heated to a certain temperature. This article is basically reporting that some electrical engineers have built an emitter that remains stable at higher temps.
The emitter itself can be heated by sunlight. So, yeah presumably you’d need to concentrate sunlight on the emitter in order to make the tpv work.

By: Ronald Brakels

Ronald Brakels — Sun, 20 Oct 2013 16:49:00 +0000

Let’s see what Materials Science And Engineering An Introduction, Eighth Edition has to say…

Crikey! There are a lot of words in this book!

Oh look! There’s a whole section on “Generalized Creep Behaviour”. That could be handy to know.

Let’s see, Stress and Temperature Effects, Data Extrapolation Methods… Well, the short answer is, yes, materials that can withstand high temperatures are generally good at withstanding not so high temperatures.

By: JamesWimberley

JamesWimberley — Sun, 20 Oct 2013 14:41:00 +0000

Does a material’s standing up to 1400 deg C for an hour tell you anything useful about whether it will stand up to 60 deg C for 30 years?

By: Teddy

Teddy — Sun, 20 Oct 2013 07:45:00 +0000

The Idea is to try to test out long term heating issues in as small a time frame as is possible.

It’s not a great real world test, but waiting 30-40 years for results is also not so feasible.

By: J_JamesM

J_JamesM — Sun, 20 Oct 2013 04:42:00 +0000

I agree. Where exactly is 1400° C going to be relevant? Have they started putting solar cells in foundries?

By: JamesWimberley

JamesWimberley — Sun, 20 Oct 2013 00:03:00 +0000

I don’t get the relevance of this. The temperatures cited (1200-1400 deg C) are miles above anything a solar cell could experience. They could just be reached in solar tower collectors, but the article doesn’t mention CSP. So the connection to improved silicon cells is handwaving. What am I missing?

BTW, science runs everywhere in the world on SI units, including degrees Celsius or Kelvin. You can use Fahrenheit if you insist to talk about air-conditioning to an American audience.