Solar tax credit question.

I've read several places that one qualifies for a 30% tax credit for installing a solar system on an RV. Just talked with my accountant & he tells me he's not sure, but he thinks only your primary residence qualifies. He didn't have time to research it, & I'm going to make the purchase anyway, so I didn't ask him to look it up for me. We'll figure it out at tax time. Does anyone have a definite answer?



Thanks