Record high performance with new solar cells
November 3, 2008
Researchers are reporting record-high efficiency levels for a new generation of solar cells. Credit: National Renewable Energy Lab
Researchers in China and Switzerland are reporting the highest efficiency ever for a promising new genre of solar cells, which many scientists think offer the best hope for making the sun a mainstay source of energy in the future.
The photovoltaic cells, called dye-sensitized solar cells or Grätzel cells, could expand the use of solar energy for homes, businesses, and other practical applications, the scientists say. Their study is scheduled for the November 13 issue of ACS' The Journal of Physical Chemistry C.
The research, conducted by Peng Wang and colleagues — who include Michael Grätzel, inventor of the first dye-sensitized solar cell — involves photovoltaic cells composed of titanium dioxide and powerful light-harvesting dyes. Grätzel cells are less expensive than standard silicon-based solar cells and can be made into flexible sheets or coatings. Although promising, Grätzel cells until now have had serious drawbacks. They have not been efficient enough at converting light into electricity. And their performance dropped after relatively short exposures to sunlight.
In the new study, researchers describe lab tests of solar cells made with a new type of ruthenium-based dye that helps boost the light-harvesting ability. The new cells showed efficiencies as high as 10 percent, a record for this type of solar cell. The new cells also showed greater stability at high temperatures than previous formulas, retaining more than 90 percent of their initial output after 1,000 hours in full sunlight.
Article: "New Efficiency Records for Stable Dye-Sensitized Solar Cells with Low-Volatility and Ionic Liquid Electrolytes" http://dx.doi.org/10.1021/jp808018h
Source: American Chemical Society
Jul 31, 2008 |
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And they breakdown over time. Ho-hum. :/
A little fact checking next time please!
They just changed the standards for efficiency.
The old 41% is now 23% according to another Physorg article. The efficiency statement is now based on usable capture as opposed to overall capture.
There's only so much surface area on the planet, and we'll need as much as we can get for vegitation.
Roof's/walls of buildings are the only real good spots for solar energy.
Roof-mounted solar might be enough by itself -- a typical 1kW household could be powered by 5 to 10 square meters of 100% efficient panels depending on location -- but solar panels can also be put in deserts, along cleared power line routes or freeways, on arid mountaintops, maybe in the oceans or at the poles though it would be expensive -- and, eventually, in space. But, honestly, rooftops alone will probably be enough.
You realize that 100% efficiency is impossible when talking about electricity.
Hell, right now 60% is a stretch.
I don't want to be a cynic but it just seems we are heading backwards.
And yes, if someone comes up with a solar cell collector that I can spray on my roof that achieves 10% efficiency, then I will consider it, unless, it degrades to 1% efficiency after 12 months.
100% may be impossible, but 95% is not. Costs will eventually come down and efficiency will go up. That is how it is with all new technologies.(except combustion engines of course) :P
where do you get a 1KW houshold from unless you live in a tent?
Name one technology or system that is over 60% efficiency in regard to energy collection and transmission.
(We'll skip the storage part right now as that'd make me have to lower the percent to 40 just to be fair.)
Ant: 1kW is about the average figure I saw on the web for typical household energy consumption. Search for "typical household energy consumption kw". Don't forget this average includes nighttime. Larger houses will consume more power -- but will also have more room for more solar panels. ;-)
The average home consumes 920 kWh per month. Not 1 kW. Your figures are wayyyy off. That and how many homes don't have 20 m^2 of surface area with access to direct sunlight?
It is not efficient enough, it's too expensive, and you can't store it. The technology has a long long way to go before it's feasable to remove a home from the current grid.
Velanarris, you apparently don't know the difference between between power and energy. One thing that should have clued you in is that Damon Hastings did not quote you a period of time, not to mention the units he used. To compare your number with his, you'd have to take 1 kW and multiply it by the number of hours in a month, which is about 730.5. This results in a monthly usage of 730.5 kWh, which is quite close to the 920 kWh you quoted. So no, the numbers are not "wayyyy off." Please get a clue.
Actually I'm quite comfortable with it, which would be exactly why I'm questioning the use of a figure of energy when talking about electrical power. Sometimes the argument isn't as complex as you desire.
I'd also note that the solar dish stirling units NOW BEING INSTALLED in western US already provide 30% net efficiency (and at very reasonable costs).