In short
- IT MW = MVA × PF × (1 − headroom) ÷ peak PUE.
- 60 MVA at PF 0.95, 10 % headroom and PUE 1.35 gives 38.0 MW IT.
- At 132 kW per rack that is 287 racks; at 8 kW it would be 4,750.
- Every megawatt lost in the chain is roughly $11–15M of capacity paid for but not sellable.
IT load from the connection
Use peak PUE for capacity and annual PUE for energy. The terms are defined in the megawatts guide.
Racks and white space
Racks = IT kW ÷ kW per rack, rounded down. White space ≈ racks × 2.6 m² up to 40 kW per rack, or 3.2 m² above, including aisles and liquid-cooling units.
| Density | Racks in 38 MW | Racks per 10 MW |
|---|---|---|
| 8 kW · industry average | 4,750 | 1,250 |
| 15 kW · cloud | 2,533 | 666 |
| 40 kW · AI, air | 950 | 250 |
| 132 kW · GB200-class | 287 | 75 |
| 230 kW · next-gen | 165 | 43 |
See the rack density section for what each step means for cooling.
Installed UPS and generators
UPS installed = IT × redundancy factor; generators installed = facility × redundancy factor. With N+1 (1.25): 38.0 × 1.25 = 47.5 MW of UPS and 51.3 × 1.25 = 64.1 MW of generators.
Energy and average draw
The business case
- Build cost = IT W × $ per W: 38 MW × $11 = $418M (an example rate; see the cost guide).
- Rent potential = IT kW × rent × 12 × leased share: 38,000 × $200 × 12 × 90 % = $82M a year.
- Simple payback on rent = build cost ÷ rent: about 5.1 years, before operating costs, power and land.
A 60 MVA AI campus
| Quantity | Value |
|---|---|
| Grid connection × PF 0.95 | 57.0 MW |
| Facility power after 10 % headroom | 51.3 MW |
| IT load at peak PUE 1.35 | 38.0 MW · 63 % of MVA |
| Racks at 132 kW · white space | 287 · ≈ 920 m² |
| UPS · generators installed (N+1) | 47.5 MW · 64.1 MW |
| Energy at 75 % load, PUE 1.25 | ≈ 312 GWh/yr |
| Build cost at $11/W | $418M |
| Rent at $200/kW-month, 90 % leased | $82M/yr · payback 5.1 yr |
Questions about capacity
How many racks fit in 1 MW?
125 racks at 8 kW, 25 at 40 kW, about 7 at 132 kW. Density changes the rack count by a factor of 15 or more for the same power.
How much IT can a 100 MVA connection support?
With PF 0.95, 10 % headroom and peak PUE 1.35, about 63 MW of IT. A lower PUE or less headroom raises it.
Why keep headroom?
For motor start-up, growth, measurement tolerance and the utility's limits. Without it the site can trip the connection at peak.
Is payback on rent the same as return on investment?
No. It ignores power, staff, maintenance, land, financing and lease-up time. It is a first sense of scale only.
Sources
- Calculator model on this site; white space 2.6 / 3.2 m² per rack including aisles and cooling units.
- Build cost and rent are example inputs, not index values.
- Worked figures are screening estimates, not a design.