In short
- Land capacity = site area × building cover × storeys × IT kW per m², which rises with rack density.
- Grid capacity for IT = grid import ÷ PUE.
- The smaller of the two is the campus; on most sites it is the grid.
- 120 ha, two storeys, 40 kW racks and 900 MW of grid give 720 MW IT in 5 buildings and 3 phases, fully live after about 54 months.
How many megawatts the land can hold
| Rack density | IT per m² of building |
|---|---|
| 8 kW | 0.8 kW/m² |
| 15 kW · cloud | 1.1 kW/m² |
| 30 kW | 1.7 kW/m² |
| 40 kW · mixed | 2.0 kW/m² |
| 60 kW | 2.6 kW/m² |
| 130 kW · AI, liquid | 3.8 kW/m² |
The curve is a planning fit to published campuses; it includes electrical and mechanical rooms inside the building, not yards.
How many the grid will deliver
The grid import covers IT and everything else, so the IT it supports is grid ÷ PUE. A 900 MW offer at PUE 1.25 supports 720 MW of IT. Compare it with the land capacity: the lower number is the campus, and it tells you which side to work on.
Buildings
Divide campus IT by the IT per building and round up. Cloud designs often use 30–100 MW buildings; AI campuses 150 MW or more. Larger buildings save land and duplicated plant but put more capacity behind one energisation date.
Phasing to the substation
Group buildings into phases that match transformer bays and grid capacity. The first phase goes live after the lead time to first power, typically 24–36 months; each further phase follows at a steady step, often 12 months. Full build-out = lead + (phases − 1) × step.
Energy, water, transformers and cost
- Facility power = IT × PUE.
- Energy per year = IT × average load × PUE × 8,760 h.
- Water per year = IT × average load × 8,760 h × WUE (litres per kWh).
- HV transformers (100 MVA, N+1) = facility power ÷ 90 MW, rounded up, plus one.
- Build cost = IT × cost per MW; $11.3M is the 2026 average, excluding IT.
120 ha, 900 MW grid, 40 kW racks
| Quantity | Value |
|---|---|
| Footprint = 120 ha × 25 % | 300,000 m² |
| Building area, two storeys | 600,000 m² |
| Land allows = 600,000 × 2.0 kW/m² | 1,200 MW IT |
| Grid allows = 900 ÷ 1.25 | 720 MW IT · grid binds |
| Buildings of 150 MW · phases of 2 | 5 buildings · 3 phases |
| First power · full build-out (30 + 2 × 12) | 30 · 54 months |
| Energy at 80 % load | ≈ 6,300 GWh/yr |
| Water at WUE 0.3 L/kWh | ≈ 1.5 million m³/yr |
| Racks at 40 kW · HV transformers | 18,000 · 11 |
| Build cost at $11.3M per MW | ≈ $8.1 billion |
The site could hold 1,200 MW, but the grid offer caps it at 720 MW, or 6 MW per hectare, above the 3.5–5 MW typical of published single- and mixed-storey campuses because of the second storey.
What moves the answer
- Grid binds: negotiate more capacity or an earlier date, lower PUE, or add on-site generation for early phases.
- Land binds: add a storey, raise rack density, or reduce setbacks and yard space.
- Time binds: energise smaller first phases, use bridging power, prefabricate (see allinMODULAR).
Questions about campus planning
How many MW per hectare should I assume?
3.5–5 MW per hectare for published campuses as a first figure; more with multiple storeys and high-density AI racks, less with large buffers.
How big should each building be?
Large enough to keep plant efficient, small enough to energise in step with the grid. Cloud campuses often use 30–100 MW; AI campuses 150 MW or more.
How many transformers does a campus need?
At 100 MVA each with N+1, roughly one per 90 MW of facility power plus a spare: 11 for a 900 MW campus.
Does build cost include servers?
No. The $11.3M per MW average covers the building, power and cooling. IT equipment comes on top and usually costs more.
Sources
- Planner model on this site; IT density curve fitted to published campuses.
- JLL 2026 average build cost; liquid cooling adder $1–2M per MW.
- Worked figures are screening values, not a design.