U.S. scientists claim world record in solar cell efficiency

I wonder what the point is of testing them at 326 times the amount of light that hits Earth on a sunny day. What's the efficiency for real-life use?

Since the PV cell is one of the most expensive component, it makes sense to use relatively cheap mirrors to concentrate a large surface exposed to the sun onto a small PV cell. This should reduce the overall cost per KW and simplify the electrical connections.

That does make sense - kinda. 326 suns works out to about 32.6Kw per square foot. I hope they come with some big heatsinks.

I agree that is like the test for miles per gallon ran with 100 octane gas. Then the car dealers push those cars to the public but the public can not buy 100 octane gas anywhere. We have not been able to buy 100 octane in over 40 years.

"but the public can not buy 100 octane gas anywhere"

I have to disagree. There is a station here, about 15 miles fom my house, where you can buy 110 at the pump. I used to fuel up my S10 pickup there. It was $4.80 a gallon, back when regular was around $1.75/gal. Very expensive, but the truck had an 11.5:1 CR V8 so it would ping on anything less. I had to get rid of the truck a couple years back, though. So, I don't know what it goes for now, but I'm sure it's insane.

you live near a NASCAR or someohter race track. That is the only place they sell it on the East coast.

A few years back, a guy I worked with drove a '68 Camaro muscle car that took the higher grade, and he bought it at the local small craft airfield. Aviation gasoline is typically 108 Octane number or thereabouts...

"you live near a NASCAR or someohter race track"

Believe ot or not, there are no tracks within an hours drive. I wish like hell there was one closer. I have been told that there used to be a 1/4 or 1/8 mile drag strip, in North Melbourne (about 20mi from me) so maybe that's why the 110 is here. It closed back sometime in the early eighties. It's rumored one of the older guys I work with used to co-own it. I'll have to ask him about it sometime.

I'm only guessing, but I would imagine it's (using 326x sun power) to get a better signal to noise ratio so they can get as accurate a measure of the efficiency as possible.

From other articles read:

Recent comments also said increased efficiency by cooling the solar cells, taking heat away from the cells.

Another recent comment was solar cells developed that can also work at night, the materials used to build the cells are typically used in night vision and infrared camera detectors.

Two companies are building solar power plants in California that will produce 200MW and 500MW, and they say 1MW is the typical energy consumption of a Walmart store. The utility that will buy the power prefers solar to wind, because the solar is present during the utility peak load time of day.

Did they allow for the energy required for the heat removal equipment, when the achieved that 40.8% efficiency?

All too often, the figures are improperly stacked up, leaving out the ones which "go against what the researchers want to say".

Kind Regards....

Good Answer, Sparkstation.

Dragon

People, don't be so negative. If they tested them the same way the old technology was tested, they still improved the light conversion efficiency by 2X. Of course there will be a price to pay for the higher efficiency. At least, it is going in the right direction.

The IC engine is about 40% efficient and we use millions of them. Once you take the losses for the other systems in the car it is much lower but we still use them.

The important point here is that some people are making the conversion technology progress and eventually, PV systems will pay for themselves in a reasonable time without subsidies.

Yes, and hopefully before the sun puts out 326 times as much energy as today. I too am wondering what the data would show at 1 solar input vs 326 solar input. Perhaps it would still double the current average, but we have not heard that yet. Perhaps this is just DOE puffery to make us think they're doing something useful. Pardon me, but I shall retain my cloak of skepticism for a while yet...and still remain hopeful!

What makes PV cells so expensive is their large size. One has to get a huge crystal with perfect structure. The yield is low, the price is high.

Their device could be made out of small chips, mounted under cheap lenses to concentrate the sun ray from 326 times the chips surface. Small chips have better yeild. It could be a neat little assembly. This would bring the PV world into the mass produced electronics. Imagine the savings...

As I said earlier, since price of the PV cell is a major component of the total cost, any technology that allow the replacement of PV by cheaper light collecting material for the same output is a winner. It is even better if they increase the efficiency along the way.

I congratulate their effort and success.

I do too, I just want a demonstration of practicality before I open the champagne.

I'm with Marcot philosophically as I feel that the perfect is too often the enemy of the good in these discussions of Solar Energy, or other Alternative Energies to Oil and Coal, in general. At some point to my mind a thing that works, is 100 percent efficient. My comparison is the old Dutch windmill, and the Sailing ship of the 1500s. Of course it is proper to work to create a better PV cell, or a better more productive system, but this does not mean we ought not commit to the materials and systems that exist. Just like I do not have to be perfect, but only ask for forgiveness to go to heavan, our machines and technologies have only to do what we need them to do in the time we are in. As a working man of the streets exact numbers are not my forte`. If I was President of BP for instance I would turn it into an energy store taking account of the infrastructure and franchise already in place. The direction you take, is more important than the numbers.

"The direction you take is more important than the numbers."

Good Answer, and very true.

Dragon