How Much Does It Cost to Run a Home Server?

A 4 bay NAS at 40 to 60 W uses 29 to 43 kWh a month, around $5 to $7.50 at the national average rate and double that in the most expensive states. A full tower server at 120 W is twice as much again.

A 3.5 inch drive uses 5 to 8 W while spinning and under 1 W spun down. SSDs use 1 to 3 W active and almost nothing idle. Eight spinning drives cost more to power than most of the systems they live in.

If nothing needs it overnight, yes. Eight hours off saves a third of the bill. If backups, cameras or a media server need it, leave it on and work on the idle draw instead.

A 4 bay NAS with spinning hard drives draws about 30 to 60 W, and this page uses 60 W. A repurposed desktop running as a server draws 60 to 120 W, and a rack server with redundant power supplies can idle at 150 to 250 W. Low-power ARM or Intel N-series boxes idle at 10 to 20 W with drives spun down.

About $91 a year for a 60 W NAS running 24/7. That is 60 W x 24 hours = 1.44 kWh a day, or about 526 kWh a year, and 526 kWh x $0.173 is $91 at the national average rate. A 120 W tower doubles it to about $182.

Not per hour, but it adds up because it never turns off. At 60 W around the clock a NAS uses about 526 kWh a year, which is more than a new full-size refrigerator. That makes it one of the larger always-on loads in a typical home.

Multiply the 43 kWh a month a 60 W server uses by your state's rate. In Idaho at 11.8 cents that is about $5 a month, at the 17.3 cent national average about $7.50, in California at 32.5 cents about $14, and in Hawaii at 40.6 cents about $17.50, using EIA residential rates.

Yes, it is a small load. A 60 W NAS plus a 15 W router and modem is about 75 W, so a 1,000 Wh power station runs both for about 11 hours after inverter losses (1,000 Wh x 0.85 / 75 W). A UPS connected by USB lets the NAS shut down cleanly when the battery runs low.

Much cheaper for always-on duty. A 15 W mini PC uses about 131 kWh a year, around $23 at 17.3 cents. A 120 W repurposed tower uses about 1,051 kWh a year, around $182, so the difference is roughly $160 a year at the national rate.

Measure the whole setup with a monitoring smart plug, then enable drive spin-down and find what keeps the drives awake. Remove add-on cards and GPUs the server does not need. Machines that only hold backups can run on a schedule or wake on LAN instead of staying on 24/7.