Wednesday, February 8, 2012

A new type of solar cell which could boost the efficiency of solar panels by over 25 percent


A new type of solar cell which could boost the efficiency of solar panels by over 25 percent compared to silicon-based cells has been developed by British scientists, but they need another two or three years to assess whether it is commercially viable.
Scientists at the University of Cambridge have developed a hybrid solar cell which is capable of converting 44 percent of sunlight into electrical power, 29 percent more than traditional cells' capability of 34 percent, they said in the journal NanoLetters on Wednesday.
Solar cells convert the sun's energy into electricity. They absorb energy through semi-conductor materials like silicon from light particles called photons, generating electrons to make electricity.
However, silicon solar cells cannot extract all the energy in a photon and much of the energy from the more energetic blue photons is lost. Usually a solar cell generates one electron from each photon captured.
"We present the first hybrid solar cell that utilizes a phenomenon called singlet exciton fission to generate two electrons for each absorbed photon in the organic material," Bruno Ehrler, lead author of the research, told Reuters.
Hybrid cells are not new and were first developed in 1996 but their efficiency needs to be increased and stabilized before they can be commercialized.
"These (hybrid cells) are the first of their kind so it is very difficult to estimate when they will go into commercialization," Ehrler said.
"The firm Eight19 works closely with the group and will put our cells in production if they turn out to be commercially viable. However, in order to assess that we need to investigate the devices further. This might take 2 to 3 years," he added.
The price of silicon-based panels and cells has fallen dramatically over the past year, cutting profit for manufacturers and putting them under more pressure to produce even cheaper products.
Fledgling technology such as concentrating photovoltaic solar, which multiplies the sun's powers up to hundreds of times, has gained the backing of some large industry players due to its promise of delivering cheaper electricity than traditional solar panels.
The university research team's new hybrid cells could help to reduce costs as well, Ehrler said.
"Since our materials can be dissolved and processed by roll-to-roll printing, we expect the actual cost of a solar panel be much lower than (with) conventional silicon solar cells."
"On an industrial scale, the cost of making the basic silicon solar cell would dominate over the cost of an organic layer printed on top of it. However, this discovery is in an early stage so it is difficult to predict the final cost and device structure," he added.
(Editing by William Hardy)

Friday, January 13, 2012

by Salma Idilbi


[Cartoons of the Syrian artist Ali Farzat]
 School "Peace House" amid the Star Plaza, the heart of the capital, Damascus, I spent all my time. Of age until the fourth and eighth centuries. It was one of the best private schools. Students belonging to families affordable. Merchants, officials, and what was then called the "middle class". In the same school, she studied the daughter of my aunt, which twenty years older than me. Many of the teachers at both the preparatory and secondary schools, was still practiced his profession. Most of its parameters who had come to the school short skirts, Srn veiled later.

Get to school when only a quarter of the eighth. Parameter "bully" or the article "military education", stands in front of the outer door. When a poor and are watching the girls from the colorful buses. Short stature. Is full. Straightening her hair is always black, soft, heavy, pouring on the small shoulders. Sodawan her eyes, coming from Atsallma overly aggressive. Stand firmly. Tight back. Kvaha Amadmoman as a result salute the flag. Do not miss any detail. Aware accommodate all the girls who troop single file drawer into the school bus. Girls who talk among them spin in the morning bus to the sound of Fairouz, narrowing the distance between their eyes and become what the Aabsat When a poor from the bus and walk towards the door of the small school. Miss N.. Do not miss any detail. Steal the smile from the mouths of students, Tantzaaha, Chdha and keep them in place Njhlh all. Laughter is forbidden. And smiling as well. Manbh its looks. Students guilty until proven otherwise. And the subject does not accept the joke. Humiliating slap in the face from here, pulling hair from there. Her husband, a martyr, a hero. Is it tough to be the wives of the martyrs to this extent? I was wondering. Allowed to take one of the students in her coat pocket, because that surely means to conceal her nails long or colored. Hair is always tied. The color of the strand must be black. "Braids" are prohibited.

To escape from the hands of Miss N.., It was impressive achievement Sbahia esteem. Gather in the large courtyard. Stand in the form of columns of Organization carefully. We do "morning greeting" clothed military. Pants and jacket its color khaki. Belt wraps _khasorna we call "range". On our shoulders stretching bands show a yellow or red on the stage of study, but very similar to the rank of officers. Ms N holds. The microphone like a professional singer. Start screaming. The sound is still stuck look back. "Get ready," you say becomes open Bta: Astaad. Nbaeid our feet a little stand by the right of the "battle." And then "relax" Bta also open. Our feet back right and annexing it to the status of the left break. "Tandem." Raise the left hand and place them upright on the shoulder of a student who stands before us. Hand should be tight and firm. Here also the subject of a joke is not likely at all. "One Arab Nation," n scream. Shouting should we answer it amounts to satisfy: with an eternal message. "Our goals," screamed again. Our part, we cry: unity, freedom, socialism. "Our leader forever." Should we answer: Comrade Hafez al-Assad. Then we do salute the flag and woe to those who do not sing or those who claim to sing. Ring the bell. We run towards the grand staircase to our ranks, we enter the cold and gloomy

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According to tradition the first gift was knowledge.