@neroden is right but it's not an all or nothing game. If you have very low tax liability, say you owe $2000 in federal tax, you get a $2000 credit to offset it. The remaining $5500 of available tax credit is lost and can't be rolled over in to next year. It's just gone. It's a NON-refundable tax credit and that's the way they work.
Unfortunately it's not a refundable tax credit where if you owe less than the credit amount, you get a check for the rest! Oh well. I'll have a Tesla to make me feel better.