YPE html PUBLIC “-//W3C//DTD XHTML 1.0 Transitional//EN” “http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd”> A rooftop solar power system is an excellent investment for any home that isn’t at the bottom of a well or otherwise suffering from major shade problems.  Earlier this year I wrote an article on payback times in Australian capitals but it’s already out of date as they pay themselves off even faster now.  The sun didn’t get any sunnier but solar power did get cheaper.  Actually the sun got less sunny, but don’t worry, that’s just a normal part of its 11 year cycle.  (It will be decades before solar panels drain enough energy from the sun for it to go out altogether.) Unfortunately, despite solar power already having an excellent return, some solar and battery salespeople just can’t help gilding the lily by providing potential customers with estimates of savings that include huge increases in the future price of grid electricity.  It’s common for these lily gilders to assume annual grid electricity price increases of 10%.  There is a  technical term for this kind of exaggeration and the term is bullshit.  But I’ll leave it up to the...