Baby steps: new solar cell efficiency record isn't awe-inspiring
By Darren Murph 
posted Jan 27th 2009 2:02PM
posted Jan 27th 2009 2:02PM
[Via Gizmag]
posted Jan 27th 2009 2:02PM
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Patience, grasshopper.
I wish I was even 40 percent efficient ... sitting here reading engadget when I should or could be doing something productive. And incidentally, why does your spellchecker flag 'engadget?' Kinda funny.
Wonder what is new over at Hulu...
Umm... the version of the comment engine I always see doesn't even have a spellchecker. Perhaps you're thinking of the spellchecker embedded in your browser?
Using Google Chrome...wouldn't think it would correct in the Engadget box, but maybe you are right.
You, sir, are correct. It is the Google browser doing the spell checking. Just tried IE and no corrections were suggested for my many misspelled words. Good catch. Good job Google. And good night.
Wow, 41.1%, i have thought this day would never come! This is truly the beginning of a new solar powered era for mankind!
When efficiency reaches 41.3% we can abandon fossil fuels all together!
That's a fact that I just made up, but it's still 100% true.
From 40.8% to 41.1% is not a baby step, it's a GIGANTIC leap, considering the fact that it can only go as high as 100%, and they must make a hell of a blackhole out of it to achieve that.
Yeah, not to mention that the time intervals seem to be decreasing exponentially. So by next year we should have 60 percent efficient cells! Assuming that this continues, of course =)
You getting bored, huh?
You better hope that these brilliant researchers don't.
Just to put this into scale:
Internal combustion engines have energy efficiency ratios of 18-20%.
And they have been finessed for over 100 years.
You know, in a typical car, only about 3% of the energy in gasoline gets converted into forward momentum.
We've been working for over a 100 years on that one...
41.1% sounds awesome to me.
But who cares if they cost $10,000/W. < $2/W PV is what we really need.
41.1% of the solar energy striking the cell being converted to electricity does not equal 41.1% of the solar energy striking the cell being converted into kinetic energy of a vehicle.
A gasoline engine by itself is far more efficient than 3%.
In the article, it explains that these cells are suitable for converting 'concentrated' (focused, etc) solar energy into electricity - if commercialised, they would be used in solar concentrating power stations, and not on your roof. So I don't imagine they'll be aiming for a consumer-level price point.
On an individual level, advances in low-cost cells are more interesting. I've been wondering about wireless sensors, for instance. How much improvement has there been in those 'calculator-size' solar cells? Can you build a device using one of those that stores enough energy to measure something once a minute and then connect to wi-fi to transmit it somewhere? Could it even work in relatively dim artificial light (as the calculator cells do)? Etc.
Bzzt! Order of magnitude error. It's more around 30%, give or take 5% either way.
Current gasoline engines are approx 16-24% efficient, with new trends with hybrids and new engine technologies pushing 30% ratings.
Ryan
ASE Master Certified Auto Technician
I think you misquoted the number. The efficiency in terms of moving you is less than 3% for each joule in the gasoline you burn up. Much of it is lost in the engine as well as moving the vehicle itself, which for American cars can be 10x+ your weight (or less if you're a fatass).
Is it just me and oliverbusch, or is this really impressive?
so - are these 40% cells going to be mass produced sometime? that would be news
Yeah, just mass produce 30% cells and I'm happy.
glad you're happy:
http://www.emcore.com/solar_photovoltaics/space_solar_cells
@ a ham sandwich
You know... these are space grade custom-made cells and you can only buy them in bulk quantity. I actually asked emcore last year and the quote I got was $6k MINIMUM
@wslcrew
yeah i know. im on the university of michigan solar car team and suffice to say we have a decent number of these.
but at least they are, in fact, mass produced!
@ a ham sandwich
Nice! I worked on batteries for Momentum project in 03-05. Had to contact emcore last year for an another project with UM though. Anyway, go Blue!
@wslcrew
Awesome! what are the odds of that?!
Go Blue!
I'll be happy to take 41.1%. Now please, for the love of everything, PLEASE start making something with all this damn research!
It's still better efficiency than a combustion engine.
+1
then again. i think ANYTHING is better than a combustion engine...
consider that for all semiconductor cells, the amount of energy you get out of them is far less than the energy required to gather the materials and purify them enough to be able to convert light into electricity... and the process itself is in no way enviromentally friendly, its quite bad actually
in that sence, gas engines are way better.
Oh, do gas combustion engines require no energy to make? Steel just magically pops out of steel mills? Oil comes out of the ground, turns into gasoline, and no pollution is generated while burning it? No? No. Photovoltaics can keep on keeping on with no upkeep other than a quick rubdown for 25-50+ years.
Considering that the leading consumer panel manufacturer sells panels at 18.5% efficiency, I'm hoping "trickle" down effect economic principles will apply in my lifetime. A greenie weenie I am not, but I do understand the forthcoming hardships America, nay, the world faces.
I think the bottleneck is not really the power but the cost. Currently to power a house can cost over $35k ($5-$8 x watt), or you could say the price of a average house if not the same house.
There are projects to bring cell that produce 1 watt x $1 - $2, so this sound more plausible for a average house.
I agree, power isn't the issue. There are printable solar cell devices in production that are aimed at the project you have described. These cells are only about 20% efficient (or maybe less), but can be more easily mass produced. In the case of powering homes, you only need a sufficient amount of roof real estate in relation to cell efficiency.
A 0.3% increase doesn't seem like much but no doubt solar cell design is quite a challenge. Here are a few reasons why this is so:
Natural sunlight is composed of many different wavelengths of light and each wavelength interacts with materials differently. This has two implications for solar cell. The first is that many different materials (or forms of a material) must be layered in order to take full advantage of the energy in each wavelength of light. Secondly, each layer of material must allow a fair amount of light to reach the lower layers. These two problems in themselves are very challenging.
Unavoidable losses due to the transformation of light to electricity adds to the difficulty.
Knowledge courtesy of my solid state devices class.
When people speak of the efficiency of cells or gas engines or whatever they are speaking of energy output over energy input, i.e what you get for what you give
In the case of solar cells, its how much electrical energy is output for the amount of light that is input. You cant really increase the amount of light coming from the sun (other than aiming the cell at the correct angle, taking away obstructions, etc.).
Since you cant change the input that much, To get more power, you need to either increase the efficiency or increase the amount of light being used (i.e increase the active area of the cell).
Although this record is pretty good, it isnt much more than a showcase, like an athlete showing off what they can do. The real practical way to harness more energy right now is to increase area.
One note is that these cells are III-V materials, which are much more expensive and less widely produced than silicon, the king of the semiconductor industry, so dont count on seeing these cells in your toys anytime soon.
I agree, power isn't the issue. There are printable solar cell devices in production that are aimed at the project you have described. These cells are only about 20% efficient (or maybe less), but can be more easily mass produced. In the case of powering homes, you only need a sufficient amount of roof real estate in relation to cell efficiency.
Please ignore that reply, wrong comment.
I agree with all, but i'm not sure if an impractical increase in solar cell efficiency should be disregarded as showing off. No doubt the materials used to make highly efficient solar cells are out of reach for mass production but this latest increase in efficiency most likely signals an increase in understanding and possibly research funding.
Thermodynamically, nothing can even come close to 100%. They should report what the max possible (carnot) efficiency is and then we'd really have a good gauge of how impressive this is.
"Typically, as wind approaches a turbine, almost half of the air is forced around the blades rather than through them, and the energy in that deflected wind is lost. At best, traditional wind turbines capture only 59.3 percent of the energy in wind, a value called the Betz limit"
Comparison with wind power.
http://www.gizmag.com/flodesign-high-efficiency-wind-turbine-based-on-jet-engine-technology/10556/
20 years ago I had a cell with 6 percent in my hands. This is quite a step forward. Ok, when will they start mass production?
41% efficiency is huge with solar cells, the potential energy in a
square meter is a huge 700 watts. most cells that people use today
are
are? are...
ARE WHAT??? Get this man a new keyboard! STAT!
Zee, he was using his solar powered keyboard.
excuse me, i'm not an expert, but what is 100 %? I guess it differs from place to place depending on sun activity, but i guess there must be also some other scale if i want to compare - dimension or price.
E.g. if I would say that i got a sollution, which can convert 40 % of some defined light source, than for me it does not necesserily mean it is 2 times better than sollution with 20 %. E.g. if the first sollution would be 10 times bigger, than for me it means that if i putt a square meter big sollar plate on my roof, i would have 5× less energy with the first sollution.
And the same with the price - if it would be 10times more expensive, than i would probably prefer the less efficient variant (depending on ROI).
So it is improvement only if the price and size is the same or better and this need to be declared to be able to decide if the new sollution is fine.
P.S.: comparing to standard engines is nonsense, as they are transfering something to energy - with sun you are "just" giving the energy some "reason" and not letting it just convert to heat (what will happen anyway, as energy cannot disapear). Bigger bottleneck may be in a way of storing the energy (batteries), as for many things you will need somewhat constant delivery even without sun.
There is even better way to get the energy - do not lose it - recuperantion - if the car is moving it has it's potential energy and if you will be able to store 40 % of it when decelerating, you could have "always on" car with just few sollar cells (for covering the rest 60 % and friction loss). The same with an energy of house - every man is like a 40 W source of heat, and every applicance is converting 100% energy in heat - create an effective heat-to-energy sollution and protect the heat loss and you will not need so effective solar cells.
When they create batteries that last 20+ years, then I'll be excited. Also, solar cells, as they age, lose efficiency, so it's debatable how much this means to Average Joe without some sort of cost-of-production / price / reliability / mass production metric.
Still nice to see things moving along, regardless.
truly when you think about it. getting half a percent more of the suns power is actually quite a lot. So small steps really are in some cases a big deal.
Im sure if there was a comparison as to how much more power these actually produced compared to old ones it would be somewhat more significant.
Interesting, this is progress compared to the last time I looked into solar cells.
slightly off topic but I like the sound of this: http://www.inhabitat.com/2009/01/26/hot-air-balloon-engine-by-solartran/
Obnoxious reporting on something as challenging as improving solar cell efficiency does nothing to educate the reader on the true level of difficulty of doing such a thing and makes it sound like researchers somehow owe us the excitement of faster progress.
Thanks for saying that. I don't care what you people think, improvement in technology no matter how small they seem to you. They are still improvements. How about a little more appreciation for the hard work.