CtrlS is building a four-phase campus at Bengal Silicon Valley in New Town, Kolkata, on five acres leased from the state for 99 years, at a reported ₹2,200 crore, targeting more than 60 MW at full build. Phase one, at 16 MW, opened in August 2025. This record adds zero megawatts to the registry, because it is the umbrella and the building underneath it is recorded separately — and that decision, which is correct, is also why West Bengal’s counted capacity in this file is wrong by a factor of fifteen.
1At a glance
2The aggregate that counts nothing
A registry has to decide, for every record, whether its megawatts are new or already inside another record. This one is already inside. The campus carries the ceiling; the building carries the capacity.
| Record | MW | Role | In the total |
|---|---|---|---|
| PRJ-089 — this campus | 60 at full build | umbrella for four phases | no |
| PRJ-090 — Kolkata DC 1 | 16 | the building that exists | also marked no |
| Net effect on the registry | 0 | — | nothing counted |
That last row is a defect and this page exists partly to say so. Rather than mark the campus non-additive and the facility additive — which is how most operators’ records in this file work — both are marked non-additive, so Kolkata’s 16 operational megawatts appear in no total at all.
The consequence is measurable. West Bengal has ten records in this registry and contributes 1.1 MW to the counted total, while 16 MW has been running in New Town since August 2025. Anyone who read the state tally without the record would conclude Kolkata is a rounding error. It is not; it is eastern India’s largest data centre.
Count the facility, hold the campus as a ceiling. That is the rule applied to every other multi-phase project in this registry.
Until that change is made, any West Bengal total derived from this file understates the state by more than 15 times. We would rather publish the flaw than the wrong number.
3Five acres, four buildings
The land economics of this project are the part competitors should study.
| Item | Value | Note |
|---|---|---|
| Site area | 5 acres | about 2 hectares |
| Buildings | 4 | phase one is a single G+2 structure with a technical floor |
| Lease | 99 years, from the state | allotted 2022; construction started after registrations in 2023 |
| Capacity at full build | 60 MW and above | 12 MW an acre, which requires vertical build |
| Neighbours on the same estate | NTT and ST Telemedia | CtrlS is the third operational data centre at Bengal Silicon Valley, not the first |
| Cable | Digha subsea landing station | expected operational in 2026, which is the reason this site is in New Town rather than elsewhere |
Twelve megawatts an acre is the number to keep. By comparison, a large single-storey campus in Maharashtra runs at eight to nine megawatts an acre. A five-acre site can only reach 60 MW by stacking, and stacking is what makes the eastern India numbers work at all.
The second fact worth keeping is that CtrlS arrived third. NTT and ST Telemedia were already at Bengal Silicon Valley, which means the power, the fibre and the state relationship were established before CtrlS committed ₹2,200 crore. Late entrants pay less to learn a market and more to differentiate in it.
4₹36.7 crore a megawatt
| Basis | Arithmetic | ₹ crore per MW |
|---|---|---|
| Campus as announced | ₹2,200 crore ÷ 60 MW | 36.7 |
| Campus at the operator’s upper bound | ₹2,200 crore ÷ 80 MW | 27.5 |
| Phase one as reported | ₹370 crore ÷ 16 MW | 23.1 |
| The operator’s own figure | stated by the colocation president | 35.0 |
| This registry’s new-build band | other operators | 52 to 70 |
Every version of the number lands between ₹23 and ₹37 crore a megawatt. This is the cheapest large-scale construction in this registry, and it is cheap for reasons that are not transferable: state-leased land, a five-acre plot instead of a hundred-acre campus, tier-2 city labour, and a specification built for enterprises rather than accelerators.
It is also the anchor for the whole eastern India argument. A gigawatt built at CtrlS’s Kolkata economics costs about ₹36,700 crore. The same gigawatt at the AI-campus band of ₹66 to 70 crore a megawatt costs ₹66,000 to 70,000 crore — which is precisely the number the operator has attached to its 1 GW Bodh Gaya proposal. Same country, same year, a factor of nearly two, and the difference is entirely about what is being built rather than who is building it.
5Timeline
- West Bengal allots five acres at Bengal Silicon Valley on a 99-year lease
- Construction of the first building begins after registrations
- CtrlS announces a ₹2,200 crore, four-phase, 60 MW-plus campus; the colocation president says it could reach 60 to 80, even 100 MW
- Phase one opens at 16 MW of IT load, the first Rated-4 facility in eastern India
- The operator continues to describe the campus as above 60 MW with no published dates for the remaining three phases
- No announcement of phase two, no land record for the additional buildings, and no timetable for the remaining 44 MW
6Limits and open questions
7Sources
Sources: CtrlS Datacenters press release on the Kolkata inauguration, CtrlS Kolkata data centre page, Business Standard and The Telegraph on the ₹2,200 crore campus and land lease, Data Center Dynamics, Times of India, Indian Infrastructure, Baxtel Kolkata listings, DataCenterMap Kolkata listings.