PV of the future: organic photovoltaics
Michael Grätzel, inventor of the dye-sensitized solar cells, those made with organic dyes, wins the Millennium Technology Price.
A sign of confidence in a technology that, thanks to very low prices and application flexibility, it promises a lot in a not too distant future.
"For his invention and development of organic solar cells, known as 'Grätzel cells', whose excellent price-performance ratio will allow them to have a huge potential to enter the future portfolio of energy technologies." It reads the dedication of the Millennium Technology Price, awarded last month to Michael Grätzel, Director of the Laboratory of Photonics of the Ecole Polytechnique Fédérale de Lausanne, along with 800 thousand euro to be invested in research.
The Finnish prize for technological innovation - born in 2004, when he went to Tim Berners-Lee, the inventor of the world wide web and awarded every other year - in this edition was won precisely by the inventor of organic photovoltaics ( dye-sensitized solar cell), thin-film cells made using a combination of titanium dioxide and organic dyes that promise to reduce costs compared to traditional mono or polycrystalline silicon, but also with respect to the thin film currently on the market.
Discoveries in the 70s and since then the subject of ongoing research, this type of cell that mimics the process of photosynthesis, according to the International Committee of the competition has all it takes to carve out a leading role in the world of photovoltaics. This recognition comes as this type of cell begins to be marketed.
The interest in this technology for some years is very high. In Italy, for example, was born in late 2006, by the will of the Lazio Region and the Department of Electronic Engineering, University of Rome Tor Vergata, a center for research and industrialization of the technology (the Chose (Qualenergia.it, the new photovoltaic speaks Italian.) Some companies, such as British or Australian G24 Innovations Dyesol, meanwhile, have already started to sell products based on this technology, and many others, even as large as Sony, are in the process of doing so.
Without going into problematic techniques, it can still highlight some of the advantages of these cells. First of all the price given by the simplicity of construction and the materials used. There is talk of a cost per watt of about one tenth compared to traditional modules and about half of those thin film. The thin films are made commercially in large part with cadmium and tellurium, materials quite rare; organic cells are built with cheap materials and available in quantity: primarily (in addition to glass), titanium dioxide and dyes based organic pigments synthesized biologically, as such also by the blueberries or the eggplant. In addition to this, the construction is simple, much less expensive in terms of energy consumed than competing technologies and also non toxic substances are used.
Add to this some technical features that make organic cells potentially interesting: in the lab with an efficiency of 11% (comparable to that of the most efficient thin film), are ideal for extensive applications. Obtain excellent results with low insolation and thanks to the type of construction dissipate heat more quickly, so that the high temperatures might compromise its performance to a lesser extent compared to the other technologies. One of the problems to be solved is associated, in addition to general electrical stability of the cell, the use of liquid electrolytes (but they are studying alternatives such as gels and other materials) which freeze at low temperatures, thus blocking the production of electricity.
Organic cells are also flexible, durable and can also be transparent to the solar aspect, which opens a series of unpublished applications. Already on the market there are clothing and bags equipped with photovoltaic cells, while much could be done in the integration building. The example provides the same Grätzel, illustrating the technology the Guardian: a transparent film for glasses; application that is already possible using photovoltaic amorphous silicon gel, but with one big difference: if the cost per watt of silicon gel is about 2 Euros, that of the film in organic cells provided by Fujikura, the Japanese company that is going to sell, it would be about 36 cents.
Probably the organic cells do not yet represent the future (commercial) immediate of photovoltaic, but along with other innovative technologies, such as nanostructures, are lines of research and development to intensify in the coming years to reach significant industrial production, perhaps by the end of the decade.
08/07/2010
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Translated via software
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Source:
Italian version of CercaGeometra.it