Protetor solar feito com café

Gowok:

I have looked into this issue as well, and fnndiig data does take some serious searching. Part of the problem is that it is very hard to fully calculate the energy inputs required to create a system, let alone to correctly average these costs across the many types of PV systems available. In speaking to solar installation experts, what I understand is that today's solar panels are lasting a tremendously long time. As with hybrid car batteries, there is a set period of years covered by warranty and a period of years that the cells are expected to still gather a large (90% or so) amount of their stated power. But, the reality is that installers are seeing the systems work at 95% efficiency multiple decades after installation. This makes the calculation even harder (we don't know when the system will actually stop saving energy), but has helped me to believe that the PV systems will save a significant amount of energy over their usable lifetime. This will only improve over time as the new systems we keep reading about come to market.In searching for answers I found some research I have linked to this answer. Basically- Australian study concludes a system lasts 30 years, takes the first 8-11 to pay back the energy (60% of which is from the wafer manufacture). However, they note that systems may last 40-50 years! They further project that a system created in 2010 will likely require only 2 years to pay back, due to the increasingly efficient technology.- June 2006 article on a study that averages several studies to conclude a payback time of 4 years.- National Renewable Energy Laboratory study concluded a 4 year pay back.The above articles also make it clear that there is a very favorable net pollution reduction as well. PV seems to be a great way to go!I don't want to stray off topic too much, but you may also wish to look into solar water heaters, which are often simpler (likely lower energy input) and generate the same energy reduction for a home (but at a lower $ cost).