Princeton Digital Group is adding three buildings and 100 MW of IT capacity to its MU1 campus in Airoli, Navi Mumbai, taking it to 150 MW across five buildings on about 15 acres, inside a 50-acre IT park. The first phase of the expansion is scheduled for delivery in 2026. It is the largest single building-tier addition in Maharashtra and one of the best-documented projects in this registry: capacity by building, phasing, a US$160 million green loan from three Indian banks, a dedicated 220 kV GIS substation, Mumbai’s first IGBC Platinum data centre certification and India’s first hourly carbon-free energy matching scheme, run with Tata Power Renewable and Flexidao. The one thing that is not clean is the smallest: the two existing buildings are described as 48 MW in one trade report and 50 MW everywhere else. Two megawatts, and both numbers are published, so both are on this page.
1At a glance
2MU1, building by building
| Component | Buildings | MW | Status |
|---|---|---|---|
| DC1 | 1 | Part of the 48 or 50 MW | Delivered Q4 2022 |
| DC2 | 1 | Part of the 48 or 50 MW | Live 2024-25 |
| Live subtotal | 2 | 48 or 50 | Operating |
| Expansion, three buildings | 3 | 100 | Under construction, first phase 2026 |
| Campus at full build | 5 | 150 | — |
| Implied capacity per expansion building | 3 | 33.3 | Arithmetic, not published |
The 100 MW expansion is a tripling: 50 becomes 150. That is the phrase PDG uses, and it is accurate — three new buildings more than double the two that exist. The per-building figure of 33.3 MW is arithmetic on a total that has not been broken down per building, and is labelled as such.
What matters commercially is the phasing. PDG says the first phase of the 100 MW is scheduled for delivery in 2026 and does not say how many megawatts that phase contains. So the honest position in October 2026 is that some portion of 100 MW is close to revenue and the rest is not, and the split has not been published.
The registry counts the full 100 MW in the building tier because the phase is under construction and the capacity is stated. Someone buying capacity here should assume less is available this year than the number suggests.
3The 48-or-50 megawatt question
| Source | Live capacity | Date | Wording |
|---|---|---|---|
| Trade press, DCD | 48 MW | August 2026 | “currently offers 48MW across two buildings” |
| Operator and repeated elsewhere | 50 MW | 2025 to 2026 | “the first two buildings with 50 MW capacity are operational” |
| DCD, campus coverage | 50 MW | May 2026 | “the first two buildings at the site are live with a combined capacity of 50MW” |
| Difference | 2 MW | — | 4% of the live total |
Two megawatts is 4% of the live campus and 1.3% of the campus at full build. It is also, in a state where the building tier totals 355.0 MW, a rounding difference.
The registry publishes both and counts neither: the live capacity belongs to the parent campus record, which is a container and is excluded. The 100 MW expansion is counted because it is a specifically described phase with a stated IT capacity for three named buildings.
That asymmetry looks arbitrary and is not. A phase with a stated capacity and a construction start is a building. A campus with two live buildings and a total is a ceiling. The registry counts what can be attributed and excludes what cannot, and it does that consistently across 242 records — which is why the operational number is a floor and the ceilings are published separately at 22,200.8 MW.
Money is made in the gap between what an operator announces and what a buyer can verify. A 4% discrepancy on live capacity is small, and it is the only discrepancy in this record.
Contrast it with the same operator’s Indian portfolio claim on PRJ-240, where four named campuses add to 432 MW and the company states a portfolio of approximately 1 GW. That is a 2.3-fold gap, not 4%.
4Cost and finance
| Item | Amount | Scope |
|---|---|---|
| India programme | About US$1 billion, ₹8,360 crore | MU1 expansion plus Chennai CH1, announced September 2024 |
| New Delhi-equivalent commitment | US$2.5 billion | Cumulative India commitment after the March 2026 acquisition |
| MU1 green loan | US$160 million | July 2025, Axis Bank, Kotak Mahindra Bank and Canara Bank |
| Airoli Knowledge Park lease | ₹10.42 crore per month | 1 million sq ft across three buildings, registered 1 April 2025 |
| Programme cost per MW, India | ₹36.3 crore | ₹8,360 crore divided by 230 MW, at the ₹83.6 per dollar implied by the article; ₹38.4 crore at Gridvik’s fixed ₹88.40 |
| MU1 specific capex | Not published | The phase split of the 100 MW is not disclosed |
₹36.3 crore per megawatt across the India programme is cheap against this registry’s mainstream band of ₹51.4 to ₹60.1 crore, and it is explained by three things visible in the record: a shell leased from a REIT rather than a site assembled parcel by parcel, an existing 220 kV connection at Airoli, and a 100 MW phase built alongside a live campus rather than as a greenfield.
The ₹10.42 crore monthly lease is the single most useful number here for anyone modelling Mumbai. At ₹125 crore a year for one million square feet, it is about ₹1,250 per square foot per year of rent on the shell — before a single rack is installed. That is the layer of Mumbai data centre economics that never appears in a cost-per-megawatt table.
The green loan is also a signal rather than a number. US$160 million from three Indian banks for one campus means the project is bankable on its contracted power, not on the operator’s balance sheet — which is the threshold every other Mumbai developer in this registry is trying to cross.
5Why the campus is 15 acres and the park is 50
Two acreage figures appear in every write-up of MU1 and they are not in conflict. MU1 occupies about 15 acres inside a 50-acre IT and IT-enabled services park at Airoli, and the one million square feet it has leased comes from three buildings in that park owned by a Mindspace REIT entity.
| Figure | What it measures | Consequence |
|---|---|---|
| 15 acres | The MU1 campus at full build | The land the five buildings occupy |
| 50 acres | The wider Airoli IT park | Shared infrastructure, access, existing power and fibre |
| 1 million sq ft | Leased floor area across three buildings | The shell, not the land |
| 3.3 MW per acre | Density at full build on 15 acres | Low by Indian hyperscale standards; driven by building height and floor plates |
3.3 MW per acre is a much lower land efficiency than NTT Bengaluru 4 at 7.9 MW per acre or PDG’s own HY1 at 5.7 MW per acre. Mumbai land prices explain it: at Airoli, the constraint is capital per acre, not land per megawatt, so the campus is built to the height the floor plates allow and no further.
That is the trade every Mumbai developer makes, and it is why Maharashtra’s 820.2 MW of announced capacity is spread across more, smaller parcels than Karnataka’s. The registry records acreage where it is published for exactly this comparison, and 15 acres for 150 MW is the Mumbai answer.
6How this record is counted
| Record | Type | MW | Additive | Treatment |
|---|---|---|---|---|
| PRJ-026 | Campus aggregate | 150 | No | Container ceiling; excluded, published in the ceilings set |
| PRJ-239 | Expansion phase | 100 | No | Counted in the building tier |
| PRJ-242 | Live buildings DC1 and DC2, combined record | 48 | No | Counted in the operating tier |
This was the most consequential counting decision in the Maharashtra file, and it cut against the operator. Until 26 October 2026 the registry counted the 100 MW that does not exist yet and did not count the 50 MW that did, because the phase had a record and the live buildings did not. PRJ-242 now closes that.
That is a genuine defect in a building-level registry, and it is disclosed as one. The reconciliation of 26 October 2026 recovered 1,186 MW of capacity that had been lost the other way — children of orphaned containers that never entered a total. MU1’s live buildings are the remaining case: they are inside a counted-nowhere campus and have no record of their own.
That gap has been closed. PRJ-242 was created on 26 October 2026 as a combined record for the two live buildings at 48 MW — one record rather than two, because no per-building split is published, following the PRJ-095 and PRJ-161 precedent. Maharashtra’s operating total moved from 328.7 MW to 376.7 MW. The number is a floor, and this page says so.
7What would change this record
| Item | Effect |
|---|---|
| Separate records for DC1 and DC2 | Adds about 48 to 50 MW to Maharashtra’s operating total and to the national figure |
| The megawatt split of the first delivery phase | Allows part of the 100 MW to move towards operating |
| Confirmation of 48 or 50 MW | Resolves a 2 MW ambiguity, and settles the per-building average |
| A commissioned-capacity statement at delivery | Converts the building tier into operating capacity, which is where the registry’s number is weakest |
The first item is worth more than everything else on this page. Two records would add fifty megawatts of live capacity to the national operating total and would make Maharashtra’s figure correct rather than conservative.
8Sources
Sources: Princeton Digital Group announcement of the India expansion, September 2024, covering three new buildings at MU1 taking the campus to 150 MW across five buildings on about 15 acres and a 72 MW Chennai CH1 campus, within a US$1 billion India programme; Princeton Digital Group press release, July 2025, on the US$160 million green loan from Axis Bank, Kotak Mahindra Bank and Canara Bank and confirmation of two operational buildings at 50 MW with the first 100 MW phase under construction; Data Center Dynamics, August 2026, stating 48 MW across two buildings and 150 MW across 15 acres; Data Center Dynamics, May and July 2026, on MU2 groundbreaking, the 50-acre Airoli park and India’s first hourly carbon-free energy matching scheme with Tata Power Renewable and Flexidao; Data Center Dynamics, February 2025, on the DC2 launch; a REIT lease registration report of April 2025 covering one million square feet at Airoli Knowledge Park at ₹10.42 crore monthly; Princeton Digital Group OCP Ready v2 press release describing MU1 as 150 MW of critical IT capacity across five buildings with a dedicated 220 kV GIS; Gridvik records PRJ-026 and PRJ-240. Record verified 26 October 2026.