At the recent PV Expo 2010 in Tokyo, Kyosemi Corporation demonstrated their Sphelar® solar cells, which is the trademark given to a proprietary spherical solar cell product. Unlike conventional flat solar cells, Sphelar® is a spherical shape, which makes it capable of generating power with greater efficiency and of flexible applications.
According to Kysosemi Corp, conventional flat solar cells are unable to effectively harness indirect light, such as reflected and diffused light. In addition, the sun takes on a many different positions according to the season and time of day, so in order to obtain a good supply of power, there was a need to change the orientation of the solar cell by constantly following the sun. Sphelar® captures light from all directions, which means it can catch reflected light and diffused light. In addition, there is no need to track the sun. The spherical light-receiving surfaces achieve unprecedented high generation efficiency.
With a diameter of a mere 1 to 1.5mm, Sphelar can be connected either in parallel or in series enabling diverse spherical products to be created, such as dome-shaped solar cells and "flexible" solar cells aligned on soft film substrates. Sphelar is perfect for situations where the installation of a flat solar cell would block the field of view. It is also possible to create "power-generating window glass" while maintaining a certain level of transparency. In addition the cells can also be embedded in flexible surfaces, allowing them to take on unusual shapes or be bent if necessary.
Kyosemi Corp reports that conventional flat solar cells are produced by slicing crystalline silicon ingots, generating a large quantity of "Kerf loss" in the production process. In contrast, Sphelar is produced using a unique process whereby melted silicon is subjected to free fall, and spheres are formed naturally by the microgravity conditions, so there is hardly any waste of raw materials at all. This results of course in a dramatic reduction in costs, and helps ensure the efficient use of silicon, a finite resource. Sphelar is an environmentally-friendly product, not only in terms of performance but also during the production phase.
Credit and images Kyosemi Corporation
For more read : Energy Harvesting and Storage for Electronic Devices 2009-2019
