29 April, 2017

Building a photovoltaic solar panel using transparent polycarbonate (Updated)


Update: Before you continue reading, please let me discourage you to use polycarbonate, (as I explain at the end of the post): You will be loosing money for the only reason that the cells and the polycarbonate doesn't have same expansion coefficient and lets the water go through it (very slowly), and all the efforts to avoid this disadvantages will fail miserably.


In this post we will see how to build a photoelectric panel DIY the most economical way, yet it is safe and durable (has to endure 25 years). As we shall see, the difficulty of manufacturing is very high, so I recommend it only for the handyman ;). In addition the process is long, but very satisfying if you like the "do it yourself" and are fascinated photovoltaic panels.
I have seen many examples in Internet short - lived home panels , some prepared with wooden frame , I doubt that last more than ten years, or in sealed with silicone tight box (so that moisture comes but then condenses inside unable to leave quickly, corroding cells), whereby the potential savings to the panel in a home goes for the short duration of efficiently it.
As discussed in the previous post , my intention was to use polycarbonate, three times it economical than glass, plus much safer and lightweight whose only problem is that dilates 3 times more than glass, and has a light output somewhat lower than the glass (and falling further to whiten with the sun), but stays within a reasonable range during the first 30 years, which is what interests us.

To fasten the solar cells, I have sought more easily and economically; unused support or back cover, but linking them directly to the polycarbonate, and thus kill several birds with one stone :
  • Reduces material costs,
  • Quicken the panel,
  • Avoid possible accumulation of moisture and / or water, as the polycarbonate is not totally impermeable (no plastic is, unless a barrier metal), so it is desirable that no gaps where moist air can accumulate.
  • It allows some light to pass between the cells, so that the bottom remains partially illuminated.
  • Cells give one the more "fresh" are higher performance; per ° C above 25, panel lose 0.5% efficiency. If we let the rear "air" only with a protective coating (paint, epoxy or silicone), will be best refrigerar├ín, last longer and give more electricity.

19 April, 2017

Maintenance of the DIY solar thermal collector

Getter and repaired
Hello dear readers, I do not know in your area, but here in northern Spain we have had a February 2017 very very windy, with gusts over 100 km / h  (some kind of cyclogenesis ), so strong that it removed literally one of the panels of cellular polycarbonate, and after the noise we heard, we have found, pushed by the wind literally against a tree!


So light it is (1 cm wide and 1 mm wall), who knows where we have found it if the tree was not in the middle of his path. Even it had a brown mark, a sign that before it arrived there, it hit the tiles of the house, partially breaking it.


But this would not have happened if the panels had been properly anchored, and better protected from the wind. On the one hand, the wood of extreme suffering the ravages of rain, rotting it, it should put more sheltered. And secondly, the screws that secured panels only the timber were fastened, when should having crossed and fastened to the rigid metal under it much safer.