$1 per watt refers to an industry standard of a theoretical peak energy production with ideal sunlight and does not include installation, mounting brackets and

$1 per watt refers to an industry standard of a theoretical peak energy production with ideal sunlight and does not include installation, mounting brackets and inverters. My calculation a few years ago figured a total cost of $2.5 a peak watt would be a break even (after subsidies), for residential use in areas with good sunlight.