On the same day that the 54,000 yen electricity bill came, we got the warranties from the installers of our solar panels. The power conditioners are guaranteed for ten years, and the panels are guaranteed to produce electricity for 25 years. If the house falls down, and all the bits in it stop working, at least we will still have a small power plant, which should be worth something unless somebody starts making free electricity. The guarantee is for between 5.5 kW and 10 kW, which means at least 60% of the rated value.
Of course a guarantee is only valid as long as the company giving the guarantee is still there. That company is Suntech, which according to Wikipedia is the largest manufacturer of solar panels in the world, with an annual production capacity of 1.8 giga watts, and over 13 million panels sold in 80 different countries.
For a while we were looking at solar thermal, or to put it in earthy Germanic terms rather than fancy Latin, hot water from the sun. We would have been lucky to get a five year guarantee on a system, and probably would have had engineers coming round every month or two to fix it, or at least pretend to fix it while each time making it worse.
With no moving parts, photovoltaics are much more reliable, and these will probably be generating electricity long after I stop generating carbon dioxide.
