This Friday the solar PV system should be installed, and is something we have wanted to get done as soon as possible so that we can start producing our own energy (and making a return on the investment).
Having a solar PV system installed is a key feature of the project. As such the house was designed to to have the most optimal of for installing solar panels. For our location Shiga, Japan, the best angle of the roof is approximately 30 degrees. As can be seen, the front of the house which faces SSW (the closest we could get to due south) has a shallower and longer aspect than the steeper back roof.
After looking at many options we decided on getting CIS thin film panels. The reasons being that out of the different kinds of panels available:
- they have the lowest embedded energy (up to 40% lower carbon footprint)
- they don’t contain toxic substances such as lead or cadmium
- they have good performance in both hot conditions and cloudy/shady conditions
- they’re made in Japan (local)
- they look good!
- they’re cheap
The main disadvantages:
- they are new and relatively unproven (although most commercial PV installations seem to be opting for them)
- they’re less efficient so need more space, but if you have the space, a 5kw system is just that; 5kws, regardless of the efficiency.
The three main types of panels currently on the market:
- Amorphous Silicon also called “Thin Film” of which CIS is included