This guy explains it quite well so you can argue with him now.
http://naiyerjawaid.com/project-irr-and-equity-irr-a-curious-connection/
There is no equity at the beginning of the project because nothing is paid. I understand the problem people have with it because I struggled with it and hated the idea that a return could be achieved without any capital expenditure, but I'm not going to argue with it. It is what it is.