CtrlS is building the largest private data centre campus in India at Navi Mumbai: 13 buildings, 3 million square feet, 30,000 racks at design, and 700 MW of ultimate IT load, behind a 300 MW gas-insulated substation scalable to 700 MW. Five buildings are operating at a combined 116 MW. The operator’s own building cards add to 118.8 MW, so even the built figure has two versions. This record adds zero megawatts to the registry, and this page is where that choice does the most damage.
1At a glance
2700 megawatts and 116
Two numbers describe this campus and the ratio between them is the whole story.
| Measure | Today | Next | Design |
|---|---|---|---|
| Buildings | 5 | +2 (DC 6, DC 7) | 13 |
| IT capacity | 116 MW | +95 MW | 700 MW |
| Racks | not published per building | not published | 30,000 |
| Floor area | not published | not published | 3 million sq ft |
| Power per square foot | — | — | 233 W |
116 of 700 is 17%. That is not a criticism — a thirteen-building campus takes a decade and this one started in 2015. It is the correct way to read any campus claim: the design number is what the substation is sized for, and the built number is what earns rent.
The two numbers are also regularly swapped. A press release that says the campus has 700 MW is describing land, grid sanction and ambition. A vendor who quotes 700 MW in a pipeline spreadsheet is quoting something that will not exist for years, and possibly not ever in the same form.
3Four cards, 118.8 megawatts
The operator publishes four facility cards for the buildings that exist. They add to 118.8 MW, which is 2.8 MW more than the 116 MW a trade report attributed to the same five buildings in July 2026.
| Card | Power | Racks | Floor area |
|---|---|---|---|
| DC 1 and DC 2 combined | 40 MW | 5,555 | 394,177 sq ft |
| DC 3 | 10 MW | 1,045 | 146,000 sq ft |
| DC 4 | 36.8 MW | 2,936 | 265,000 sq ft |
| DC 5 | 32 MW | 2,750 | 228,482 sq ft |
| Total of the four cards | 118.8 MW | 12,286 | 1,033,659 sq ft |
A 2.8 MW gap on a 116 MW base is 2.4% and it is not worth chasing. What is worth noting is the shape of the estate. DC 1 and DC 2 together are 40 MW across 5,555 racks — 7.2 kW a rack. DC 4 and DC 5 are 68.8 MW across 5,686 racks — 12.1 kW a rack. The campus is being rebuilt at twice the density in the same estate, which is exactly what the Indian market requires and exactly what the 2015 buildings cannot do.
A separate directory figure puts DC 1 and DC 2 at 36 MW, split as 20 MW and 16 MW. The operator’s own combined card says 40. Gridvik records 40 and notes that the pair has been described three ways: 36 MW combined, 40 MW combined, and 24 MW for DC 2 alone in a 2020 release.
423 kW a rack by design
The design numbers make a claim that no individual card does.
| Input | Value | Result |
|---|---|---|
| Ultimate IT load | 700 MW | — |
| Design rack count | 30,000 | — |
| Average density at full build | 700 MW ÷ 30,000 | 23.3 kW a rack |
| Floor area | 3 million sq ft | — |
| Power per square foot at full build | 700 MW ÷ 3 million | 233 W a sq ft |
| For comparison, the built cards | 7.2 to 12.1 kW a rack | half to a fifth |
A campus designed for 23 kW a rack is a campus designed for accelerated computing, and the company says so — its AI-ready material claims support for up to 250 kW a rack with liquid cooling, and racks up to 45 kW on air with high delta-T designs.
The gap between the 12 kW being built in DC 4 and DC 5 and the 23 kW implied by the design is the gap between what customers currently buy and what the operator is laying foundations for. That is a rational thing to build and a difficult thing to finance, which is why the pacing matters more than the total.
5The substation that explains the campus
Every Indian campus story is really a grid story, and CtrlS tells this one more explicitly than most.
| Item | Value | Note |
|---|---|---|
| Gas-insulated substation | 300 MW | described by the company as Asia’s largest; commissioned at 150 MW and doubled to 300 MW in 2024 |
| Scalable to | 700 MW | the same number as the campus design, which is not a coincidence |
| Sources | three | the company claims 100% power availability from diversified paths |
| Captive solar | 125 MW at Nagpur | covering about 60% of campus energy; N-type panels on tabletop land along the Mumbai–Kolkata highway |
| Solar commitment | more than 1 GW by 2030 | against a stated goal of 100% renewable operations |
The substation is the tell. A campus that commissions 300 MW of gas-insulated switchgear before it has 120 MW of buildings is not guessing about demand; it is buying an option on it. That option is what makes 700 MW credible and what makes the intermediate years expensive.
The solar farm is the other half of the same logic. A 125 MW captive plant covering 60% of the campus’s energy is a hedge against tariff escalation, and it is the kind of asset that a buyer of this business would value separately from the buildings.
6₹121 crore a megawatt
| Item | Value | Source |
|---|---|---|
| CPP Investments commitment | ₹7,000 crore | June 2026, equity plus a joint venture |
| Pre-money valuation | ₹44,914 crore | reported alongside that transaction |
| Operational capacity | about 370 MW | company statement, June 2026 |
| Implied value per operating megawatt | about ₹121 crore | Gridvik arithmetic |
| Nxtra, for comparison | ₹91 to ₹110 crore a megawatt | from its March 2026 round at $3.1 billion on 250 to 300 MW |
| Project pipeline | 4.4 GW | company target; a rating agency projects 950 to 1,000 MW by 2029 |
Two numbers matter here. The first is ₹121 crore per operating megawatt, which is 10 to 30% above what Nxtra’s March 2026 round implied for its own estate. CtrlS is being marked as the more valuable business per megawatt of capacity it runs, and the reasons are visible: a 300 MW substation, a captive solar farm, Rated-4 certification across the estate, and campuses in more cities.
The second is the pipeline gap. The company says 4.4 GW is at various stages. A rating agency projects 950 MW to 1 GW operational by 2029. If the analyst is right, roughly 3.4 GW of the stated pipeline is not going to be operational in any forecast anyone is underwriting — and if the company is right, the current valuation is a fraction of what the business is worth in five years. Both are published. Only one is bankable.
₹121 crore for every operating megawatt. It converts a capacity announcement into a price, and a price is what a buyer, a seller or a competitor can act on.
Apply it to the 700 MW campus and the finished asset is worth ₹84,700 crore on today’s mark. That is the size of the bet in Navi Mumbai.
7The record that counts nothing
This campus is marked non-additive, correctly, because the buildings inside it carry their own records. The problem is that those buildings are marked non-additive too.
| Record | MW | In the total |
|---|---|---|
| PRJ-094 — this campus | 700 ultimate, 116 built | no |
| PRJ-095 to PRJ-101 — the building cards | 40, 10, 36.8, 32 and others | no |
| Net effect | 0 MW | nothing counted |
Add the Kolkata case and the size of the understatement becomes clear. 118.8 MW of live Navi Mumbai capacity and 16 MW of live Kolkata capacity — 134.8 MW — appear in no total in this file. The registry’s counted figure is 2,420.4 MW, and it is a floor rather than a sum.
Twenty-eight records in this registry are both non-additive and described as operational, and they sum to 1,925.4 MW. Most of those are aggregates that contain other records and must not be added. The specific defect is narrower: where a live building has no additive sibling, its megawatts vanish.
Count the facilities, hold the aggregates as ceilings — the rule the registry already applies to Nxtra, STT and NTT in most markets.
Under that rule the national count would rise by roughly 135 MW immediately. We would rather show the flaw and the fix than publish a number that cannot be defended.
8Timeline
- The first buildings at Mahape enter service
- DC 2 is launched, later described at 24 MW and 1,800 racks across 132,000 square feet
- Grid capacity at the campus substation doubles from 150 MW to 300 MW, with headroom to 700 MW
- Five buildings operate at about 116 MW; DC 6 and DC 7 at 95 MW are listed as upcoming; a 125 MW captive solar farm is completed
- CPP Investments commits up to ₹7,000 crore at a reported pre-money valuation of ₹44,914 crore
- No construction dates for the six remaining buildings, and no reconciled built capacity between 116 and 118.8 MW
9Limits and open questions
10Sources
Sources: CtrlS Mumbai data centre page, CtrlS campus and visit pages, CtrlS AI-ready infrastructure page, Data Center Dynamics on the 125 MW solar farm and on the campus build, TelecomTalk on the 300 MW substation, The Hans India on the gas-insulated substation, Baxtel Navi Mumbai listings, datacenterlocations, dcmarketinsights, and Indian market commentary on the Mumbai data centre nodes.