federal 30 percent tax credit

Is the federal 30 percent tax credit for solar pv only a one time usage?
If I want to add on to my array and have already used the 30 percent tax credit in a previous year am I able to use the 30 percent tax credit again in the future?
Poleikleng
If I want to add on to my array and have already used the 30 percent tax credit in a previous year am I able to use the 30 percent tax credit again in the future?
Poleikleng
Comments
Reusable tax credits - don't let the politicians hear about that one - they would love it.
It can be used every time you "place in service" more solar generation.
However, I don't know how much red tape you have to go through to do an installation, but I tell people they are better off to do it all at once. Also, if you can't use all the tax credits in the current year, you are allowed to carry the excess forward to the next year.
Thanks for the response.
Poleikleng
You can carry the credits forward, BUT, and as a non-tax-professional with the warning that you should consult your own professional, I think the time limit for carrying them forward is 2016.