Short answer: This is a legal question better addressed to the entity that owns the equipment that needs upgrading for the project, and/or a lawyer with appropriate specialization.
Slightly less short answer: My understanding is that (in general) the developer is, in essence, paying the utility or other grid entity to defray the costs of the upgrade, and so the equipment is owned by the grid entity. However, I've heard anecdotally that there sometimes are more complicated arrangements for some projects, so I really do recommend that you seek advice from a lawyer with expertise in this area.
------------------------------
Emily Moog
------------------------------