Re: Efficiency
>Consider how many kettles of water you can boil (both temperature and phase change) from just one bottle of Calor gas.
Given what is possible from a relatively small domestic solar-thermal/voltaic installation, the Calor gas bottle (or equivalent) shouldn't be necessary for most of the year.
One of the things about solar energy is it makes no difference whether or not you have solar panels, the same amount of energy will be hitting your roof everyday, so in some respects once you can collect sufficient for your daily needs (most of the time), efficiency and efficacy of usage become relatively unimportant.
Biting the hand that feeds IT
