Investment Tax Credit - solar panel

My son lives with me and is paying for half of my solar panel project.  Can he claim half of the tax credit? He is not an owner of the home, but does reside here.  The current tax code defines home as where you reside and does not specify ownership, but many forums explaining the new ITC tax credit specify you must own the home?  I am confused by this.  Can anyone explain? Can he claim the the tax credit?  Aren't tax credit transferrable anyway?