If taking "electricity" off the equation!?

Hello everyone.

If I had the option of not paying for electricity at all what would be the most efficient set up. (Cost-Hash)

At the moment I am planning on the following:

Motherboard Asus Prime H270-Plus
Intel Celeron G3900 2.8GHz
RAM Team Elite 4Gb DDR4 2400MHz
Power Supply HP 80PLUS PLATINUM 2450W
SSD Kingston 300V 60GB
Power Riser pci-e x1 to x16
Adapter M2 to PCI-E 4X
AMD Radeon RX 570 or AMD Radeon RX 580

Let me know your thoughts!

Thank you!