STT GDC states 68 MW of IT load for Chennai. Its four Chennai cards read 3, 26, 15 and 17 MW — a sum of 61. The remaining 7.2 MW is Chennai 7, which the operator files under a different campus: the 45 MW Siruseri site. So the Chennai headline only closes if a building from another portfolio is counted inside it. And once the stages are laid out, 32 of the 68 MW is under construction. Operating capacity today is 29 MW — 43% of the headline.
1At a glance
2Sixty-eight against sixty-one
Every other STT city portfolio either reconciles or leaves a small unexplained residual. Chennai leaves the largest one, and it has an identity inside it.
| Building | MW | Stage | Counts toward 68? |
|---|---|---|---|
| Chennai 1 | 3 | operational | yes |
| Chennai 2 | 26 | operational | yes |
| Chennai 3 | 15 | under construction | yes |
| Chennai 4 | 17 | under construction | yes |
| Subtotal, four cards | 61 | — | 7 MW short of the headline |
| Chennai 7 | 7.2 | unverified | filed under a different campus |
| All five | 68.2 | — | closes the headline |
Chennai 7 is a real building. The problem is where it sits in the operator’s own structure: its parent record is the 45 MW Siruseri campus, a separate multi-building site with its own capacity claim. Counting it inside a 68 MW Chennai city headline means one building appears in two portfolios.
Either the 68 MW includes Siruseri and is not a city figure at all, or the 68 MW is 61 MW and the page rounds upward by more than a megawatt. The operator publishes the second and describes the first.
A market number for Chennai built on 68 MW double counts. Siruseri already claims 45 MW, and 7.2 of the megawatts inside that 45 are also inside the 68.
Anyone summing STT Chennai across both pages ends up 7.2 MW too high, on top of a headline that is already 47% unbuilt.
3The borrowed building
Siruseri is a separate campus with its own capacity claim, and this registry tracks it separately as PRJ-019 at 45 MW.
| Structure | Published | Contains | Overlap |
|---|---|---|---|
| Chennai city portfolio | 68 MW IT | Chennai 1, 2, 3, 4 and 7 | includes Chennai 7 |
| Siruseri campus | 45 MW | Siruseri buildings including Chennai 7 | contains Chennai 7 |
| Overlap | 7.2 MW | Chennai 7 in both | an operator structure that permits double counting |
This is not a data error in this registry — the source file flagged it and kept both records separate with a note requiring reconciliation. It is a data error in the operator’s published structure, or at least an ambiguity that the operator has not resolved.
For a buyer the practical effect is small in rupees and large in method. Seven megawatts is not going to change a Chennai decision. But if a headline can quietly absorb a building from another portfolio, then no headline in the set is safe to use without checking the cards — which is the argument this registry has been making for thirty pages.
4What is actually operating
Chennai is the first STT portfolio where the stages are explicit enough to separate what exists from what is being built.
| Stage | MW | Share of headline | Buildings |
|---|---|---|---|
| Operating | 29 | 43% | Chennai 1 and 2 |
| Under construction | 32 | 47% | Chennai 3 and 4 |
| Borrowed from Siruseri | 7.2 | 11% | Chennai 7 |
| Total | 68 | 100% | the headline |
Twenty-nine megawatts operating in Chennai is a real business. It makes STT the fourth or fifth largest operator in a market where AirTrunk publishes 128 MW, PDG 72, CapitaLand 53 and Nxtra 46.
But the market number that circulates is 68. And 68 is a portfolio figure that includes a construction site, a borrowed building and two buildings that are genuinely running. Those are three different things sharing one number, and only one of them can be sold to a tenant this year.
5The ₹4,200 crore question
The company has announced a multi-campus Chennai expansion at ₹4,200 crore. Applied to the 32 MW under construction, that is a cost per megawatt worth checking.
| Measure | Figure | Reads as |
|---|---|---|
| Announced expansion investment | ₹4,200 crore | a multi-campus programme, not one building |
| Capacity under construction | 32 MW | Chennai 3 and 4 |
| Implied cost if all of it is for those two | ₹131 crore a MW | well above the ₹30 to ₹40 crore Indian range |
| Implied cost if it funds 100 MW of future build | ₹42 crore a MW | in line with the market |
| CtrlS Hyderabad DC 3, for comparison | ₹38.5 crore a MW | a full high-spec build |
The ₹4,200 crore is a programme figure and almost certainly covers more than two buildings — the announcement is about multi-campus expansion, not Chennai 3 and 4. That is the point: a programme number and a building number cannot be divided into each other, and doing so produces a cost per megawatt that is either alarming or meaningless depending on which scope is right.
What can be said: Indian greenfield data centre build costs cluster between ₹30 and ₹45 crore a megawatt. Chennai’s land is expensive and its power is not cheap, so a figure at the top of that range is plausible and one four times higher is not.
6Procurement
7Limits and open questions
- The headline does not close without a borrowed building. 61 MW of Chennai cards against a 68 MW headline.
- Chennai 7 sits in two portfolios. Resolving its identity would fix both the city headline and the Siruseri campus.
- No racks, floor area or PUE for any Chennai building.
- Card values are rounded on the operator page, which the source file flags explicitly.
- The ₹4,200 crore programme is unscoped and cannot be matched to buildings.
- What would close it. A reconciliation of Chennai 7, and delivery dates for Chennai 3 and 4.
8Sources
Sources: STT GDC India Chennai city page, STT GDC India Chennai multi-campus expansion announcement, STT GDC India facility pages for Chennai and Siruseri, STT GDC India corporate site, and Indian market commentary on the Chennai data centre market.