Nonbusiness Energy Property Tax Credit
The Nonbusiness energy property tax credit, in the United States, provides a nonrefundable personal tax credit for Federal income tax purposes, for making a home more energy efficient. (Unlike a deduction, which lowers taxable income, a tax credit reduces the actual tax paid, dollar-for-dollar.) This credit was added to the Internal Revenue Code by the Energy Policy Act of 2005.
Source: Wikipedia — Nonbusiness Energy Property Tax Credit (CC BY-SA 4.0)