One thing u have to consider if u are doing this is that depending on the energy corporation u are dealing with ( in our case Synergy in WA ) is that for u to recieve a rebate on excess energy generated u may have to be in credit for a certain time before u are eligable for credits ( Synergy has a 3 month ! time period. That was what we were told when we had our system installed just over a year ago. )
But it sure makes a diff to your power bill
Marcus.