In addition to all of the above, there are requirements in the new code that need to be met that will drive the cost waaaaay high. To feed the grid (or even parallel it) at any time requires expensive equipment, skills and knowledge far beyond the average HO. Besides, unless this is a charging battery style kind of system, it is impracticable to think that you can set up any sort of an array that is capable of supplying the average household without spending a lot of money on the arrays and there interconnection etc.
