"Installing alternative energy equipment in your home can qualify you for a credit equal to 30% of your total cost. The credit is available through the end of 2019. After that, the percentage steps down each year and then stops at the end of 2021.
Qualifying equipment includes solar-powered units that generate electricity or heat water. The credit is only available for improvements you make to your residence. This can apply to a second residence as well.
As a credit, you take the amount directly off your tax payment, rather than as a deduction from your taxable income. Other than the cost of the system, there's no limit to the dollar amount of the credit."
Please read this article for more information - Federal Tax Credit for Solar Energy: https://turbotax.intuit.com/tax-tips/going-green/federal-tax-credit-for-solar-energy/L7s9ZiB4D