Advantages of Polycrystalline Modules
Heckert Solar has intensely argued with available and new technologies for the electricity production from solar energy. As a module manufacturer focused on rooftop designs it appears to us that the multi- or polycrystalline technology seems most interesting for markets in Middle- and South-Europe.
Compared with the mono-crystalline technology, which is also offered by Heckert Solar e.g. for the North European market, polycrystalline modules offer the following advantages:
|
Modern cell production becomes less energy-intensive currently: The running time it takes to compensate the production energy needed further sinks. In accordance with an investigation of ETH Zurich / PSI Villingen in 2000 production energy of a PV module is compensated within less than six operational years by its solar electricity generation. In the whole-ecological analysis solar electricity proved to be 3 times more ecological than the normal Swiss electricity mix (with a high number of hydroelectric power plants), in comparison to the European electricity mix it is better even more significantly. |
|
The production process of polycrystalline cells is clearly less energy-intensive than it is for mono-crystalline cells, because e.g. lower temperatures are needed.
|
The general advantage of the higher efficiency of mono material is used up almost totally by the surface loss being inherent in the production procedure. As a result in the module built less surface can be used obviously by the solar cell material (see accompanying picture: on the left the mono-crystalline cell). |
|
A clear advantage of the polycrystalline cell is, finally, also the slower degradation. The performance loss runs clearly slow as compared to mono-crystalline cells. Hence, about the years calculated, polycrystalline cells offer better yields.
Also the performance temperature coefficient is better with polycrystalline cells. The cells heat up more slowly than mono-crystalline. Because every warming leads, however, to lower performance, polycrystalline modules as a rule reach better yields in Middle- and South-Europe than mono-crystalline ones.
On account of these facts the ancillary industry has concentrated increasingly upon the manufacture of polycrystalline cells. This means that today there is a clearly bigger offer for poly- than for mono-crystalline cells - concerning the number of suppliers as well as concerning the overall output volume. More competition means, finally, always an optimized price / performance ratio what you profit from as an end user.
