Assuming renting their datacenters doesn't cost them any more than running them for themselves, and plugging 15B a year of revenue (which ignores X entirely and other forms of revenue) you get 5.4B income, more than Starlink 4.4B income (which is slightly subsidized by the launch segment)
electricity is a major cost. that 1.5B/mo is part for renting the hardware, part paying the lease on the building, and a significant part (I have no idea what %) is paying for the electricity.