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New Solar Cell Sets Record For Energy Efficiency
Lucas123 writes "After three years of work, German and French researchers have achieved a new world record on converting sunlight to energy through a photovoltaic cell, achieving a 44.7% rate of efficiency, which was measured at a concentration of 297 suns. The efficiency rating means the solar cell collects 44.7% of the sun's spectrum's energy, from ultraviolet to the infrared spectrum, which is converted into electrical energy. The team of researchers said the technology places them on the path to achieving their roadmap of 50% efficiency in solar energy conversion."
Thats better than the 25-30% gasoline efficiency. So it sounds good to me! http://en.wikipedia.org/wiki/Engine_efficiency
Take this sig and smoke it.
Look at the graph at http://en.wikipedia.org/wiki/Solar_cell_efficiency (about half way down). All the multijunction solar cells are run under concentration ranging up to ~1000 suns (1000:1 focusing of the suns energy). What's really impressive is that they are getting closer and closer to the 86% efficiency limit imposed by Carnot. Just like with Wind (~59% limit imposed by Betz's Law), our solar cells are approaching as good as we can get.
Here is a graph of solar cell efficiency showing the different kinds of materials used to make them. The typical solar cell is silicon (blue on the graph) and maxes out at 27.6% efficiency.
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Multi-junction cells are expensive to produce, using techniques similar to semiconductor device fabrication, usually metalorganic vapour phase epitaxy but on "chip" sizes on the order of centimeters. In cases where outright performance is the only consideration, these cells have become common, they are widely used in satellite applications for instance, where the power-to-weight ratio overwhelms practically every other cost.
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"...a photovoltaic cell, achieving a 44.7% rate of efficiency, which was measured at a concentration of 297 suns"
This means that they use mirrors to focus the light onto the panel. Since high-efficiency panels tend to be expensive, the more light you can concentrate on it, the better. The fact that it can handle a near 300 fold increase in throughput is a good thing. These are not going to be used on a residential roof flat panel anytime soon.
It really depends on your local power company NET/FIT rates, federal solar panel import protections and state/city building/code regulations.
Some areas ensure you get real cash back for feed in back to the grid. Others have do not offer so much export cash to homes with solar.
City building/code regulations can also be costly in some areas.
http://freeingthegrid.org/
http://en.wikipedia.org/wiki/Net_metering#United_States vs http://en.wikipedia.org/wiki/Feed-in_tariff#United_States_2
http://finance.yahoo.com/news/solar-panel-next-granite-countertop-161321343.html
http://www.fool.com/how-to-invest/personal-finance/home/2013/09/15/net-metering-how-a-little-known-policy-can-shave-h.aspx
When energy prices going up, you get a FIT, the cost of a solar install in your state is fair, your home has newer appliances... the pay back period is not so unaffordable over years.
Domestic spying is now "Benign Information Gathering"
"Germany's Energy Poverty: How Electricity Became a Luxury Good" Spiegel 09/04/2013
German consumers already pay the highest electricity prices in Europe. But because the government is failing to get the costs of its new energy policy under control, rising prices are already on the horizon. Electricity is becoming a luxury good in Germany, and one of the country's most important future-oriented projects is acutely at risk.
In the land of the blind, the one-eyed man is king.
Capacity factor for PV solar in the U.S. is about 0.145. That is, if you plop down a 1000 Watt panel angled at your latitude, and measure its power generation for a year, it'll average out to 145 Watts. It incorporates everything - weather, angle of the sun, night, etc. Across the country, it ranges from about 0.185 in the desert southwest, to 0.11 in New England.
From the Wikipedia article, in 2012 Germany had 32.6 GW of installed PV solar capacity, and it generated 28 GWh of electricity. A year is 8766 hours, so that's an average generation rate of 28000 GWh / 8766 h = 3.19 GW. So their PV solar capacity factor is 0.098 (Numerous hits on Google reporting instantaneous generation and generation over 24 hours notwithstanding - those don't matter, only the long-term cyclical average does, a natural cycle of seasons being one year.)
Basically, Germany is a terrible place to install PV solar. The only reason it's viable there is because their green energy initiatives have driven up the cost of their electricity to about $0.34/kWh (vs about $0.20/kWh for France and the UK). Numerous studies put the cost of electricity from PV solar at about 2x-5x the cost from other sources. So normally it wouldn't be cost-effective. But if you raise electricity prices to 3x what it is in the U.S., suddenly PV solar becomes financially viable.
They use Fresnel lenses, not mirrors : http://www.soitec.com/en/technologies/concentrix/components/
PS: I worked with Concentrix (now Soitec). Cool company.