No. If you receive a rebate from the installer, that is the same as a price discount from any other merchant, and is not taxable. BUT, you must figure the 30% solar credit on your net price after the rebate, not the gross price. If you already filed your tax return, you need to file an amended return to change the cost you used for the solar energy credit, and repay part of the credit.
If you receive money from the electric utility as an incentive, that is taxable miscellaneous income, but it does not reduce the cost of the installation or the allowable credit.
