Cost to run a Custom TrueNAS tower (6x HDD)
A Custom TrueNAS tower (6x HDD) (Tower/custom server) draws roughly 55 W at idle and up to 130 W under load. Run 24/7 at a typical ~78 W and the US average of $0.17/kWh, it uses about 683 kWh a year and costs roughly $116.16/year ($9.68/month). In higher-priced regions such as Germany (€0.40/kWh) the same device costs about €273.31/year. Adjust the calculator for your own draw and electricity price.
Source: HomelabWatts wattage database. Data as of 2026-06-13.
DIY ATX TrueNAS/ZFS box with six 3.5" drives.
Idle vs load running cost
| Scenario | Power | Energy / year | Cost / year (US) |
|---|---|---|---|
| Idle | 55 W | 482 kWh | $81.91 |
| Typical 24/7 | 78 W | 683 kWh | $116.16 |
| Full load | 130 W | 1,139 kWh | $193.60 |
Estimate: ~25-35 W base platform plus ~5-8 W per active 3.5" HDD plus spin-up surges. Spun-down idle is lower. Source: HomelabWatts wattage database, data as of 2026-06-13.
Cost by region (typical 24/7 draw)
| Region | Price/kWh | Cost / month | Cost / year |
|---|---|---|---|
| United States (avg residential) | $0.17 | $9.68 | $116.16 |
| Germany | €0.40 | €22.78 | €273.31 |
| France | €0.28 | €15.94 | €191.32 |
| United Kingdom | £0.25 | £14.23 | £170.82 |
| Spain | €0.25 | €14.23 | €170.82 |
Prices from electricity price presets (EIA / Eurostat), data as of 2026-06-01. Excludes standing charges and taxes.
Frequently asked questions
How much does it cost to run a Custom TrueNAS tower (6x HDD) per year?
At a typical 24/7 draw of about 78 W and the US average of $0.17/kWh, roughly $116.16 per year ($9.68/month). At €0.40/kWh in Germany it is about €273.31. Use the calculator above for your own price.
How many watts does a Custom TrueNAS tower (6x HDD) use?
Approximately 55 W at idle and up to 130 W under load. Estimate: ~25-35 W base platform plus ~5-8 W per active 3.5" HDD plus spin-up surges. Spun-down idle is lower.
Are these figures measured or estimated?
Estimated. They are compiled from manufacturer specifications and community wall-meter measurements; your exact draw depends on configuration, firmware and attached storage. Measure at the wall for a precise figure.
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Last updated: 2026-06-13