Cost & Energy
Infrastructure TCO Reference
Typical CapEx vs OpEx shares, cost-per-rack and cost-per-kW planning ranges for server rooms and small on-prem data centers in Europe, and the PUE × rate sensitivity behind them. Use alongside the Infrastructure TCO Calculator.
Last updated: July 2026
Terms
- TCOTotal Cost of Ownership
- The full price of running something over its whole life, not just what you paid to buy it — including electricity, maintenance and staff time. Often far higher than the purchase price alone.
- CapExCapital Expenditure
- Money spent upfront to buy equipment or build something — a one-time purchase cost, as opposed to the ongoing running costs (OpEx).
- OpExOperational Expenditure
- The ongoing cost of running something day to day — electricity, staff, maintenance contracts — as opposed to the one-time purchase cost (CapEx).
- PUEPower Usage Effectiveness
- How much total electricity a facility uses for every unit that reaches the actual computers. 1.5 means 50% extra goes to cooling and power losses. Lower is better.
- UPSUninterruptible Power Supply
- A battery backup that keeps equipment running for a short time if mains power cuts out, giving generators time to start or equipment time to shut down safely.
CapEx vs OpEx over 5 Years (typical SME facility)
Illustrative split for a 10-rack, 5 kW/rack facility at PUE 1.5 and €0.30/kWh with modest staffing — the calculator's worked example.
| Component | Share of 5-year TCO | Driver |
|---|---|---|
| Energy | ~54% | IT load × PUE × €/kWh × 8,760 h — the single biggest item |
| Staffing / operations | ~22% | 24/7 coverage creates a fixed floor that doesn't scale with racks |
| IT CapEx (annualized) | ~16% | Refresh every 4–5 years |
| Infrastructure CapEx (annualized) | ~7% | Racks/UPS/cooling cost more than IT upfront, but live 10–15 years |
The pattern to remember: OpEx — led by power — is roughly three-quarters of a typical 5-year SME TCO. The purchase price is the smaller part of the decision.
Energy Cost per kW of IT Load per Year (PUE × rate sensitivity)
Annual electricity cost per kW of IT load, continuous operation (8,760 h) — this is why PUE and your €/kWh rate are the biggest levers in the whole model.
| PUE | €0.20/kWh | €0.30/kWh | €0.40/kWh |
|---|---|---|---|
| 1.3 (well-optimized SME) | €2,278 | €3,416 | €4,555 |
| 1.5 (typical air-cooled) | €2,628 | €3,942 | €5,256 |
| 1.8 (legacy / unmanaged) | €3,154 | €4,730 | €6,307 |
Read: a 20-rack facility at 5 kW/rack (100 kW IT) moving from PUE 1.8 to 1.5 at €0.30/kWh saves ≈€79k per year — measure yours with the PUE Calculator.
Planning Ranges — Cost per Rack per Year (SME scope, Europe)
All-in annual TCO per rack (annualized CapEx + OpEx), assuming PUE ~1.5, €0.25–0.35/kWh and proportionate staffing. Planning-level orientation only — your inputs decide.
| Rack profile | Typical density | TCO per rack / year | Notes |
|---|---|---|---|
| Light (network/edge) | 1–3 kW | €8k – €18k | Staffing share dominates at small scale |
| Standard server rack | 4–7 kW | €25k – €45k | The common SME case — energy ≈ half |
| Dense compute | 8–20 kW | €50k – €90k | Energy dominates; cooling design matters |
Hyperscale/AI racks (100 kW+, liquid cooling, €10M+/MW builds) follow different economics and are deliberately outside this reference.
The TCO Method
Energy/yr = IT kW × PUE × 8,760 h × rate
Annualized CapEx = IT CapEx ÷ refresh years + (infra + build CapEx) ÷ infrastructure lifetime
Annual TCO = annualized CapEx + energy + staffing + maintenance + space + network — multiplied by the analysis period for the total, divided by racks or IT kW for the comparable KPIs.
Straight-line annualization keeps the model transparent; it deliberately excludes discounting, taxes and financing — those belong in the final financial review, not the planning comparison.
Frequently Asked Questions
Why does OpEx usually dominate TCO?
Over 5–10 years, power (IT × PUE × €/kWh) and staffing typically outweigh the upfront hardware spend — especially at EU/German electricity prices. That's why comparing purchase prices alone routinely picks the wrong option.
On-prem vs colocation — which is cheaper?
On-prem is CapEx-heavy, colo is OpEx-heavy. It depends on utilization, scale, your electricity rate and whether you already carry 24/7 staffing — the calculator compares both over your chosen period.
Do these figures apply to hyperscale/AI data centers?
No — everything here is scoped to server rooms and small on-prem facilities at 1–20 kW per rack. Hyperscale economics are a different regime.