ColorBlast™

Abstract

Solar Photovoltaics has been a major source of clean renewable energy. Globally, PV has seen an exponential rise in installed capacity in the last decade. Better accessibility of PV technologies have created new opportunities for Urban
applications. Building Integrated PV is one such promising application where PV technologies are used to generate power as well as function as a building element like facade. With dual function of PV modules, visuals plays a key role. This thesis explores one such technology ColorBlast™that utilises digital printed ceramic ink to give PV modules colour.
Currently, various colour module technologies exist but most of them lack custamisability. A module which can be customised to have any desired colour to fit an application perfectly is in high demand. ColorBlast™is a colour
photovoltaic technology developed by Kameleon Solar in the Netherlands. ColorBlast adds colour to a module by partially covering the surface of a module with digitally printed ceramic ink. ColorBlast modules can therefore be made with any colour including images.
In thesis looks into evaluating the performance of ColorBlast modules with any desired colours including images.
The most optimal way to cover the module with the ceramic ink to fit the application is explored. Furthermore, ways to improve both the visual and electrical performance are suggested.
Visual performance of the module was found to depend upon the amount of surface covered by the ink and the colour of the ink. The most effective way to evenly distribute colour across the module was to print small hexagonal
dots of area 2mm2-4mm2 and to spread it across the entire surface of the module such that the total printed area was always less than 50% of the surface of the module. By doing so, the module when viewed from a distance appears to
have a homogeneous colour. This homogeneous colour is different to the printed colour and the relation between the two was evaluated. This concept was also extended onto modules with images.
Different colour inks were found to have different transmission and reflection spectra. By measuring the transmission and reflection spectra for various inks and their combinations, the relation between the combined spectra and the proportions of primary constituents of the secondary and tertiary colours were determined. This was used to determine the change in incident light as seen by the cell. Further, it was observed that all of the transmitted light and 30% of the reflected light from the printed surface was incident on the surface of the module to generate power. The power production of a ColorBlast™module was predicted given the colour that was printed and the coverage factor.
These were also extended to ColorBlast™with images and the predicted values were found to match the observed values with less than 1% error.
When images are printed, each cell would produce different current and this would create hotspots and shorten the lifespan of the cell. Methods to reduce this by altering the current production of cells were discussed.
The power loss for a ColorBlast™module was found to depend on the angle of incidence. The yearly energy production for a ColorBlast module in an installation at Helmond, Netherlands was estimated using and was found that ColorBlast modules in this application produce 28% less power in a year.
Only the current production methods of ColorBlast with mono-crystalline Si cells and ceramic ink were studied.
Further research on ColorBlast with different ceramic inks and different Solar cells will give a better insight on how to reduce power loss and improve visuals.