Let the government pay for almost ⅓ the cost of your solar system. How does it work? If you usually have to pay a tax bill, expect to pay a lot less next year. Typically get a refund? Get ready for a HUGE check from Uncle Sam. This is not a reduction in your tax liability, it’s a reduction in your taxes owed! However, the sun is going down on the ITC. Every household has a different tax situation, consult your tax professional with questions about yours.