The Japanese company Kyosemi Corporation presented at the PV Expo 2010 in Tokyo Sphelar, spherical solar cells of very small size, which produce energy from window panes
He is about to end up run over, his mother saves himIn the future we could produce electricity by using our windows directly like solar panels. To the benefit of the environment and the energy saving but also of the aesthetics of our buildings and cities, especially the historical centers of historical, architectural and cultural value.
We had already informed you of the progress in this sense with the article dedicated to Solarwindow, which has developed a special spray to be sprayed directly on the windows of our homes, transforming them, thanks to a transparent mixture of conductive polymers, into panels capable of capturing even the diffused light coming, even, from artificial lighting.
Now it is the turn of the Japanese company Kyosemi Corporation that has taken a further step forward, shaping solar cells very small size, patented with the name of Sphelar (Spherical Solar Cell), and able to be directly incorporated into the glass of our windows and, therefore, capable of being not only in total integration with the buildings, but, being inserted in the frame, to become part of the building itself.
The spheres are of silicon, the material also used for normal photovoltaic panels, but it is the creation procedure that is completely different: drops of molten silicon are made to precipitate on the glass support and, as they fall, they solidify, thus also avoiding the waste of silicon deriving from its processing. In the traditional solar panels, in fact, the silicon ingots are cut into very thin slices to constitute the so-called wafer, that is the layer of which will be closed between the two crystals that form the module, it is inevitable that a part of the material is lost in the form of "sawdust", the so-called Kerf effect. With sphalelar it makes up for this with a single and univocal process capable of reducing, in addition to the quantity of silicon, also the production costs.
The Sphelar project was presented at the recent PV Expo 2010 in Tokyo, in which one was also provided demonstration of how the small photovoltaic spheres (which have a diameter of just 1-1,5 mm, maximum 1,8 mm) also adapt well to integration on curved windows, being able to count on a variety of products with the individual units connected together in series or in parallel and with transparency up to 80%. The very small size allow capture light from all directions, including, therefore, also diffused light and not only direct solar radiation. Furthermore, the cells, as well as being integrated into flexible surfaces, can, a bit like the glitter ones developed by Sandia National Laboratories, also take on unusual shapes or, if necessary, be bent.
We therefore hope that Sphelar will prove to be a concrete solution for energy saving and the reduction of harmful emissions into the atmosphere and that soon photovoltaic micro cells are commercially available.
Andrea Marchetti
