Massachusetts allows a 15% credit -- up to $1,000 -- against the state income tax for the net expenditure* of a renewable energy system (including installation costs) installed on an individual’s primary residence. If the credit amount is greater than a resident's income tax liability, the excess credit amount may be carried forward to the next succeeding year for up to three years. Eligible technologies include solar water and space heating, photovoltaics (PV), and wind energy systems. The original use of the system must begin with the taxpayer, and the system should “reasonably be expected to remain in operation for at least five years.”
The credit is available to any owner or tenant of residential property. For a newly constructed home, the credit is available to the original owner/occupant. Joint owners of a residential property shall share any credit available to the property under this subsection in the same proportion as their ownership interest. Any excess credit amount may be carried over to the next 1-3 taxable years.
* The term "net expenditure" is defined as the total purchase price for any renewable energy source property and installation cost less any federal tax credits and rebates/grants received from the U.S. Department of Housing and Urban Development.