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Bill Gates: We need global ‘energy miracles’

By John D. Sutter, CNN//
// -1) {document.write(‘February 13, 2010 — Updated 0103 GMT (0903 HKT)’);} else {document.write(‘February 12, 2010 8:03 p.m. EST’);}
// ]]>February 13, 2010 — Updated 0103 GMT (0903 HKT)

Long Beach, California (CNN) — Microsoft Corp. founder and philanthropist Bill Gates on Friday called on the world’s tech community to find a way to turn spent nuclear fuel into cheap, clean energy.

“What we’re going to have to do at a global scale is create a new system,” Gates said in a speech at the TED Conference in Long Beach, California. “So we need energy miracles.”

Gates called climate change the world’s most vexing problem, and added that finding a cheap and clean energy source is more important than creating new vaccines and improving farming techniques, causes into which he has invested billion of dollars.

[ . . . ]

“We have to drive full speed and get a miracle in a pretty tight timeline,” he said.

Gates said the deadline for the world to cut all of its carbon emissions is 2050. He suggested that researchers spend the next 20 years inventing and perfecting clean-energy technologies, and then the next 20 years implementing them.

(etc.)

http://edition.cnn.com/2010/TECH/02/12/bill.gates.clean.energy/index.html

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My Note –

For over 45 years there have been designs created, inventions made, breakthroughs accomplished in these areas. Bill Gates needs to speak with the CEOs and corporations throughout the US that have bought, hijacked and shelved these designs and inventions along with their patents. We don’t have another twenty years to fix this energy problem and the inherent pollution of the way it has been being done.

– cricketdiane

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Dye-sensitized solar cell

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A selection of dye-sensitized solar cells

A dye-sensitized solar cell (DSSC, DSC or DYSC[1]) is a relatively new class of low-cost solar cell, that belong to the group of Thin film solar cells.[2] It is based on a semiconductor formed between a photo-sensitized anode and an electrolyte, a photoelectrochemical system. This cell was invented by Michael Grätzel and Brian O’Regan at the École Polytechnique Fédérale de Lausanne in 1991[3] and are also known as Grätzel cells.

This cell is extremely promising because it is made of low-cost materials and does not need elaborate apparatus to manufacture. In bulk it should be significantly less expensive than older solid-state cell designs. It can be engineered into flexible sheets and is mechanically robust, requiring no protection from minor events like hail or tree strikes. Although its conversion efficiency is less than the best thin-film cells, its price/performance ratio (kWh/(m2·annum·dollar)) should be high enough to allow them to compete with fossil fuel electrical generation (grid parity). Commercial applications, which were held up due to chemical stability problems[4], are now forecast in the European Union Photovoltaic Roadmap to be a potentially significant contributor to renewable electricity generation by 2020.

(Excerpt from – )

http://en.wikipedia.org/wiki/Dye-sensitized_solar_cell

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Most solar cells are made of amorphous silicon. The problem with this is that the silicon must be of a very
Solar cells in the field
high purity and have a near perfect crystal structure. This makes it very expensive to produce. The efficiency of such a cell is also very small, typically converting only 13-18 % of sunlight to electricity. However, low efficiency wouldn’t matter if huge arrays of cells could be produced cheaply. After all, nature’s solar cells, chloroplasts in plants are less than 1 % efficient.


Electrons jump from  the valence bands into the conduction band, where
they are mobile.
Most solar powered devices rely on the same principle: a photon of sunlight boosts an electron in the material into a mobile state so that it can be used to generate electricity. The problem with this simple mechanism is that the electrons are negatively charged and will leave a positive charge. These opposite charges attract one another and therefore will tend to recombine, squandering the absorbed energy as heat or as re-emitted light.

Silicon solar cells use an electric field to push the negatively charged electrons and positive charges apart. While chloroplasts adopt a more subtle approach of separate charges by making a distinction between the units that generate the electron and those that transport it away.

Natural nanotechnolog: Chloroplast contain nanoscale molecular machinery (including pigment molecules like chlorophyll) arranged inside stacked structures, called thylakoid disks, that conevert light and carbon dioxide into biochemical energy.
Click picture to view source

Deciding to copy nature’s trick, Michael Gratzel and Brian O’Regan at the Swiss Federal Institute of Technology began research and produced the Grätzel cell in 1991.

The Grätzel cell uses intensely colored organic dye molecules to capture light energy to inject an electron from the dye into a semiconductor such as titanium dioxide (TiO2). This remarkably efficient charge separation reaction initiates current flow and the output of electrical energy by the cell.


Schematic diagram showing how a Grätzel cell work. The dye molecules attached onto the semiconductor particles are sandwiched between two glass electrodes.

How does nanoscience help?

The ideal material used in the cell must have a high surface area for light absorption and charge separation. Nanoparticles, having a comparable surface area to volume ratio, provides for just that. Titanium dioxide nanoparticles are used to make nanoporous thin film supported upon a glass substrate. The material obtained has optical transparency, excellent stability and good electrical conductivity.

[etc.]

http://www.chm.bris.ac.uk/webprojects2002/etan/Webpages/applications%20solar%20bottom.htm

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