Add $91 cost/year per 100W of internal server

For low consumption levels (<15MWh per month), midwest electricity prices out at 10.36/hr. Therefore, when calculating the relative cost of hosting a server 24/7/365.25 internally vs in the cloud you ought to add at least $90.82/year per 100W worth of internally hosted server, where that 100W must include UPS and cooling inefficiencies. Assuming a 90% UPS efficiency and HVAC COP of 3.4, that's 71W of actual server power. If your server is not designed specifically to reduce energy, expect muc...