MUM 3 at Mahape is listed by Nxtra by Airtel at 18 MW of IT power across 1,600 racks — 11.3 kW a rack, with a declared PUE below 1.55. That density is 77% higher than the operator’s older Mumbai halls and it is the clearest numerical evidence in this portfolio that new Indian capacity is being specified for denser equipment. Mahape is also the most instructive node in the registry, because it holds simultaneously 45 MW reported live, 40 MW that broke ground in January 2026, and 50 MW promised for mid-2024 that was never built at all.
1At a glance
211.3 kW a rack — the AI tell
Density is the one specification that separates a modern Indian hall from a legacy one, and it is derivable from numbers the operator publishes.
| Facility | MW | Racks | kW a rack | Reading |
|---|---|---|---|---|
| MUM 1 — Chandivali | 4 | 600 | 6.7 | legacy inner-city hall |
| MUM 2 — Airoli | 7 | 1,100 | 6.4 | legacy hall, prime location |
| MUM 3 — Mahape 1 | 18 | 1,600 | 11.3 | modern, AI-capable |
| MUM 4 — Mahape 2 | 42 | 3,600 | 11.7 | modern, AI-capable, the largest |
Those four rows are the whole story of the Indian data centre transition in one table. Two halls at about 6.5 kW a rack built for cloud and enterprise colocation; two at about 11.5 kW built for what is being ordered now. The same operator, the same city, and a 77% difference in what each cabinet can carry.
At 11.3 kW a rack, a hall can host GPU servers with rear-door or in-row liquid assistance without a full rebuild. It is not 170 kW a rack — the density TCS has claimed for its Hyderabad campus — but it is the density at which conventional infrastructure stops being the constraint. That is why this building is worth 18 MW of a supplier’s attention and the Chandivali building is not.
3Mahape: promise against delivery
This node is unusual because it contains the registry’s clearest controlled comparison between an announcement and a building.
| Proposal | Claim | Outcome |
|---|---|---|
| ZR Power | 50 MW, ₹1,700 crore | nothing built. Announced in 2021–22 with a mid-2024 operational target and no evidence of construction since |
| NTT NAV1A | 45 MW, about 5,000 racks, 400,000 square feet | reported live. Part of an 8-acre campus planned for up to 150 MW across four buildings |
| L&T Vyoma | 40 MW on 10 acres | ground broken 21 January 2026. Too early to judge |
| Nxtra MUM 3 and MUM 4 | 60 MW across 5,200 racks | listed as operating, one of them confirmed commissioned by an independent tracker |
The comparison is deliberately uncomfortable. ZR Power announced the largest single number in the node — 50 MW for ₹1,700 crore, which is ₹34 crore a megawatt — with a target of mid-2024. Four years on, there is no building. Nxtra announced nothing, built two halls, and lists 60 MW. L&T, a company with an engineering business that can actually execute, broke ground in January 2026.
The lesson is not that announcements are worthless. It is that the two things which predict delivery in this market are an operator with existing buildings and a contractor with a construction business. A first-time developer with a big number is the least reliable signal available.
ZR Power’s ₹34 crore per megawatt was well below the ₹52 to ₹70 crore cost of building. That should have been read as evidence that the outlay would not cover the project, not as evidence of efficiency.
Nearly four years later the point is settled: it did not.
4The Mumbai cluster, reconciled
Adding the four cards gives the account its proper size, and gives the market a defensible number for one operator’s Mumbai footprint.
| Measure | Value | Basis |
|---|---|---|
| Facilities | 4 | Chandivali, Airoli, Mahape 1, Mahape 2 |
| IT power | 71 MW | 4 + 7 + 18 + 42 |
| Racks | 6,900 | 600 + 1,100 + 1,600 + 3,600 |
| Average density | 10.3 kW a rack | 71,000 kW ÷ 6,900 racks |
| Mumbai share of the 250 MW national figure | about 28% | the annual report capacity |
| Mumbai share of the 300 MW March 2026 figure | about 24% | the press release capacity |
| The contradiction | the same operator has described the national platform as 120–130 MW, 250 MW and 300 MW | so the Mumbai share cannot be stated precisely |
Seventy-one megawatts and 6,900 racks is a real, operating, profitable business — and it is 28% of a national platform whose own size the operator has described three different ways in six months. That is not a criticism of Nxtra specifically; it is the state of Indian data centre reporting, and it is why Gridvik publishes the arithmetic instead of the claim.
5Timeline
- ZR Power announces a 50 MW data centre at Mahape for ₹1,700 crore with an operational target of mid-2024. Nothing is built
- NTT brings up NAV1A at Mahape, reported at 45 MW, about 5,000 racks and 400,000 square feet, within an 8-acre campus planned for up to 150 MW
- Nxtra brings Mahape 1 and Mahape 2 into service. An independent tracker later records Mahape 1 as commissioned with no leaseable power under construction
- L&T breaks ground on a 40 MW facility at Mahape, in the same node that has carried a 50 MW promise since 2022
- The operator lists MUM 3 at 18 MW across 1,600 racks with a declared PUE below 1.55, and MUM 4 at 42 MW across 3,600 racks
- No commissioning date for either Mahape hall is published by the operator, and no tenant is named
6Procurement
7Assumptions and method
| Figure | Basis | Confidence |
|---|---|---|
| 18 MW, 1,600 racks | Nxtra Mumbai page facility card | High |
| 11.3 kW a rack | Gridvik arithmetic: 18,000 kW ÷ 1,600 racks | Arithmetic |
| PUE below 1.55 | Operator card | Company declaration, not an audit |
| 77% denser | Gridvik arithmetic against the 6.4 kW a rack of MUM 2 | Arithmetic |
| 71 MW and 6,900 racks for Mumbai | Gridvik addition of the four published cards | Arithmetic on published figures |
| 45 MW live at NTT NAV1A | Trade reporting | Medium |
| 40 MW L&T Vyoma | Groundbreaking reported January 2026 | Medium |
| 50 MW ZR Power, not built | Announcement of 2021–22 with a mid-2024 target; no construction evidence located | High as a failure |
| Commissioned status | Independent tracker, not the operator | Medium |
8Limits and open questions
9Sources
Sources: Nxtra Mumbai data centre page, Nxtra by Airtel site, DataCenterMap Mumbai listings, Baxtel facility records, Data Center Hawk, Data Center Dynamics on NTT NAV1A and L&T Mahape, Gridvik record PRJ-046 for the ZR Power history, Airtel FY26 annual report.