This sounds risky... can you provide more details?
Where are the rigs located?
What are they going to be made up of? GPU? Asic? What models, and what does "upgraded" mean to you?
How do you have free electricity? That sounds unsustainable over 180 days.
lol, yeah, diff rises will make betarigs 24 hour rentals at 0.0046 in few weeks. What OP proposes is pretty much a scam if an uninformed user will buy into it.