[hga]

Where do you live?

Where I live, in SW Missouri, capital and maintenance costs might be higher due to weather (e.g. high winds, hail), and it would be useful during the summer---which the electric company would be generally thankful for, less $$$ peaking power needed---but much less so in fall and winter when it's frequently overcast.

Also, if you live in a place with high electricity rates, like California, the case elsewhere is less compelling. I probably pay on the order of 1/2 of your savings for the total power to handle a building that's almost certainly bigger and thirstier than your's (numbers on request).