Anyone know what this would mean as far as size reduction for panels of 42.8 efficiency? I worked out a complicated system that probably doesn't make mathematical sense and came up with 2.87 inches to equal the 200 watt rating of a 3x4 sanyo at 14% efficiency. I'm sure I must be off somewhere though.

Pat, there aren't sufficient details in the linked article to calculate area per watt. Since it's a concentrator panel there might be a limit to how close together these panels can be placed. So without more details its hard to say.

Thanks for the update, Jeremy. Another thing unique about this development apart from the record efficiency is that the concentrator they've designed requires no tracking.

Tracking the sun its entire path is the bane of solar concentrators. A slight error of just a few degrees and you lose output dramatically. With a lifespan of 25-30 years of most solar cells, it's a monumental engineering challenge to design a tracker that lasts that long.

This is one of the reasons PV concentrators have not taken off despite being an extremely attractive technology. The DARPA-UD system somehow requires no tracking at all. Although the concentration at 20 suns is on the low side but to achieve that without tracking is a breakthrough in its own right.

More info here: http://www.ee.udel.edu/~honsberg/

Look under publications for pdf reprints of related journal articles.

Why did I get redirected to "paint on solar cells" while this page was loading?

At what point does the efficiency become high enough that solar becomes the most feasible option; economically, environmentally, etc.?

How nice to know that it's financed by people looking to make better killing machines. Science truly is the handmaiden of warmongers.

That's pretty great. I can't wait until we can get enough juice to run our laptops from solar panels on the covers.

One Man. One Year. $100,000 online. How's he doing it?
http://www.oneyeargoal.com

Dumno how much credence to put in a story that reports "...electrons extracted from photons...".

I applaud the fact that there is research being done in this country instead of Germany. Germany's political leaders have forced the power utility companies to buy back power at 10 times the going rate. In our country, they hold the photovoltaic industry back with a repressive underfunded solar incentive rebate program. They allow the power companies to credit only a small portion of power back into the grid. If you don't use the credit, you lose it. You can not apply for a rebate unless the system has been approved in advance by the state. You can not apply for rebate unless it is installed by a licensed solar installer or master electrician. The installer has to be bonded and insured for millions. If there is a mistake on the solar incentive rebate forms (like using the wrong colored ink) , the installer may be sued for the rebate amount plus attorney fees. The system must be insured for $100,000 and have a kill switch that only the utility can access. Instead of green lighting this wonderful industry it is being repressed. Industry associations are putting up barriers to entry instead of mainstreaming this simple business. My company has a single panel using a multi energy level technology that produces 3000W per panel, but I have been unable to install any at the retail level. With our system you don't have to reduce the size of the panel, just reduce the number of panels. If we made the utilities pay like in Germany, every supermarket in America could produce enough income through unused space on their roofs, to lower the prices of food about 25%. Every school could become a profit making venture, producing enough income to pay all the salaries, material costs and upkeep.
That would reduce the property taxes in every participating community. Wake up, America.

Michael, the German system of feed-in tarrifs is good for the consumer, but it isn't insane -- you can't just go out and build the biggest PV system you can afford and start collecting 49 eurocents/kWh. There are limits on how large the system can be, and those limits correspond roughly with the amount of energy you expect to consume. Furthermore, you don't get paid for each kWh you generate, but only for each kWh you ship out to the grid. If you use exactly the amount of energy you generate, you get nothing. In other words, the scheme is meant to promote the use of PV, but not to turn John Q. Public (Johannes Q Öffentlichkeit?) into a for-profit generator of power.

On the topic of US funding for PV research, note that the funding for this particular project came not from the Department of Energy's PV budget, but from the defense budget. No federal PV funds were spent on this.

As for reducing the price of groceries by 25% -- not gonna happen, not even close. It's easy to calculate just what that would require based on Food Marketing Institute figures. The average US grocery store is about 4500 square meters and generates about $17 million in revenue annually, so to reduce prices by 25% the store would have to get paid $4.25 million for whatever energy it shipped to the grid. At 20% capacity factor (a place like Phoenix, with optimally tilted fixed PV modules) with 20% module efficiency (which Sunpower and Sanyo are close to), a store of that size will generate about 65,700 kWh annually. That means that if the store shipped all of the energy it generated to the grid instead of using it in-house, it would have to be paid $65/kWh in order to reduce food prices by 25%. That's about 100 times the German feed-in tarrif. The limiting factor here isn't technology, either, it's the amount of sunlight hitting the supermarket roof. Improve efficiency to 100% and the required rebate drops to about $13/kWh. Improve capacity factor to 100% -- which is tantamount to forcing the sun to sit directly overhead in a cloudless sky 24/7 -- and the required rebate drops to $2.60/kWh, or nearly 30 times the average residential retail electricity rate in the US.

Not that it would really matter anyway -- if utilities were forced to subsidize our groceries, they'd simply tack it onto its ratepayers' bills. They'd have to or they'd go out of business and there would be nobody to sell your excess energy to. Same goes for schools and property taxes. One way or another, electricity subsidies will come out of our pockets. The only way to reduce prices with PV is to reduce the price of PV.

I live on solar power, and I can say with some authority that until research produces a storage technology that is affordable and effective it doesn't matter if solar cells are 100% efficient. Batteries are embarassingly primitive, bulky, expensive and inefficient. Really, they're not any more sophisticated than putting a rock out in the sun and bringing it in to heat your house. THAT is the weak point, NOT solar cells.

to julie crist...

help is on the way. ultra or pico capacitors show great potential. like batteries, they can be made to store large amounts of current & discharge slowly like a battery at many times less the weight and volume. they can even be molded to form part of a structure or device. the problem right now is cost & mass production. go on line, type in ultra capacitors to find more info.

fraud
fraud
fraud
cell area /= illumination area

If you believe what is being claimed in terms of solar cell efficiency then you are just as naive as DARPA was when they selected U. of Delaware to manage the original development program. As one who has developed advanced photovoltaic cells for the government for 15 years and has seen dozens of unfounded and unscroupilous claims made, history will show these claims too are fraudalentand and the government is once again being scammed - and I fear willingly in this case to save face

Hi Alan, I am impressed by your attention to detail, but I disagree. The panels I sell put out 3,000 to 5000 watts. If legistlation were passed, say in my homestate of Florida, say for the utilities to pay 10 times the going rate or $1.11 for power generated and every year the payout declines 10% until they are paying 11 cents. If they raise their rates, they raise the payout. They eliminate the need for infrastructure improvements because the power will be generated during peak hours when its needed most and in the neighborhoods where the power is needed. This will eliminate the need for new nuclear power plants. This will also make the Sunshine State the world leader in the PV Industry. It would create millions of American jobs and make America a world leader in a dynamic growth industry. If a supermarket were allowed to use their roofspace to generate profit and to eliminate their power bills, the cost of food would drop precipitously. Imagine our public schools operating at a net profit. Imagine our retired citizens farming electricity for their pensions.

42% effiiency makes solar power more attractive. An energy website indicates that 10000 sq miles of 50% efficient solar cells could replace all of the world's current oil production.

A few on the top of each house might make a significant dent in our fossil fuel dependance.

To Michael:

I own a new upstart PV company in the planning stages of building 30 Megawatts of installed PV panels. I would love to hear more about your panels.