Summary

  • Teraco's location pages carry a critical-load figure for every named building: 70 for JB1, JB3 and JB5 combined, 14 for JB2, 50 for JB4, 5 for CT1, 50 for CT2 and 2 for DB1. The pages carry no visible publication date.
  • The Johannesburg arithmetic reconciles to the megawatt by two independent routes, and Bredell reconciles to the figure the operator assigned it in August 2025.
  • The same building's utility supply flips between MVA and MW across Teraco's own documents, and no document in the set states a power factor, so the headroom above critical load cannot be computed for JB2, JB5 or DB1.
  • Per-building capacity is documented. Per-building electrical redundancy is not: the only explicit statement is a corporate N+1 design principle published on 4 August 2025.

The two columns that do not measure the same thing

Teraco's location pages are built around two figures per building, and they are not the same kind of number.

The first is the one in the card: a bare figure with no unit suffix in the page text. 70 across JB1, JB3 and JB5 at Isando, 14 for JB2, 50 for JB4, 5 for CT1, 50 for CT2, 2 for DB1. The second figure lives in the description underneath: JB2 with "a resilient power supply of 24MVA", JB4 with 80MVA.

The card is critical IT load, meaning the load a customer's equipment draws. The description is utility supply, the capacity of the connection feeding the site. A megavolt-ampere is apparent power. A megawatt is real power. Converting one into the other needs a power factor, and not one document in this set states one.

The arithmetic gap is not pedantry. At a power factor of 0.9, 80MVA delivers 72MW. At 0.8, the same 80MVA delivers 64MW. That is an eight-megawatt swing on a building whose published critical load is 50MW, before anyone has discussed what is actually installed. That calculation is mine, not a rating the operator states.

Teraco does not always keep to its own convention. JB4's utility supply is 80MVA on the live Johannesburg page and "serviced by 80MW of utility power supply" in the release that completed the building on 12 August 2025. CT2 was specified on 13 November 2023 as receiving "90 megavolt-amperes (MVA) of utility power supply" and completed on 10 November 2025 "serviced by 90MW of utility power". Two buildings, two unit flips, no explanation, and no power factor anywhere in the record.

Where the arithmetic closes

Isando closes twice, by two different routes.

JB3 was assigned 29MW of critical power load in August 2021, when the campus as a whole was reported at 40MW. JB5 broke ground in November 2022 as a 30MW development and was confirmed complete in the August 2025 JB4 release with an additional 30MW. Add 29 and 30 and you get 59. The Isando card says 70. The difference is 11MW attributable to JB1, the one building with no standalone published rating.

The second route uses the forward-looking document. The November 2024 JB7 release puts Isando at up to 110MW including 40MW of JB7. Subtract 40 from 110 and you are back at 70. Two independent routes, same total. The card values are MW of critical IT load, and the campus aggregate is built from them.

Bredell closes as well: JB2 at 14 plus JB4 at 50 is 64, which is precisely the 64MW the 12 August 2025 release assigns to Bredell. The 13 November 2024 release assigned the same campus 63MW. The one-megawatt difference between those two releases is stated by the publisher and explained by nobody.

Where both sides of a headroom ratio are published in MW, the ratio can be computed honestly. JB4: 80MW of utility supply against 50MW of critical IT, or 1.6. CT2: 90MW against 50MW, or 1.8. Neither figure is available for JB2 (24MVA against 14), JB5 (120MVA against 30) or DB1 (4MVA against 2.2), because the operator published one side of each pair in megavolt-amperes and the other in megawatts.

Where it stops closing

Cape Town is the clearest failure. On 12 November 2025, one year to the day before this retrieval, Teraco announced a CT1 expansion in Rondebosch: 3MW of existing critical IT load plus 2MW planned for completion in early 2027. The live Cape Town card already reads 5. Either the card counts capacity that has not been built, or 2MW arrived early and the announcement was never updated. The page does not date itself, so there is no way to tell which, and a buyer pricing a CT1 commitment cannot tell from the public record whether the number in front of them is steel on the ground or a 2027 intention.

Durban is thinner still. The 15 November 2023 expansion release describes DB1 as receiving 4MVA of utility supply and providing 2.2MW of critical power, while the same release's portfolio table lists Durban at 2MW. The live card reads 2. DB1 also holds the weakest published supply position in the estate: every other site with a stated supply figure carries 24MVA or more.

Two further mismatches sit in the record, both of them definitional rather than arithmetic. JB4 is 16,000m² of white space on the location page and 17,000m² of deployment space in the completion release; those are different defined quantities and neither document reconciles them. And the 2017 Riverfields release in Bredell describes "over 24MW" of power where the current JB2 description uses 24MVA. Whether Riverfields is JB2 is an inference from location and vintage, not a mapping the release makes.

The redundancy sentence

The design article published on 4 August 2025 carries the sentence that has to hold the entire redundancy case: "Our overall design is based on an N+1 distributed redundant system, with enhanced functionality." The same article says generator sets are backup during grid failure, describes intelligent grouping to reduce the number of generators running under low load, and discusses commissioning tests across operating conditions.

That is a corporate design principle. It is not a per-building arrangement.

At site level the strongest wording is JB2's: a resilient supply of 24MVA with concurrent maintainability and additional fault-tolerance provisions. No feed count, no source substation, no UPS topology, no maintenance procedure. At site-pair level, the 25 April 2023 Cape Town article supplies the one hard separation fact in the estate: CT1 and CT2 are more than 30 kilometres apart and operate on different power grids.

Here the record runs out, and this is a ceiling rather than a finding of absence. Five technical-sheet PDFs linked from the campus pages, covering Isando, Bredell, CT1, CT2 and DB1, did not come back on 12 November 2026. Whatever per-hall feed arrangements, as-built ratings or redundancy designs they contain is unknown to this article. The narrower statement still matters: utility feed count, source substations, UPS configuration, fuel autonomy in hours, and the load a single generator or feed failure is designed to shed appear in no document that could be retrieved.

What a buyer can actually check

Five questions, all answerable before signature.

  1. The contracted quantity, in one unit, for the hall being bought: MW of critical IT or MVA of supply, with the as-built date attached.
  2. Whether the published utility figure is exclusive to that building or shared across the campus. JB5's 120MVA is stated without saying which.
  3. Redundancy per hall as a schedule, not a principle: feed count, source substations, UPS topology, generator autonomy in hours, and the load shed on a single failure. If the answer is the N+1 sentence, the buyer has been handed a design philosophy.
  4. Whether planned capacity is inside the number on the table. CT1's card reads 5; the operator's own announcement says 3 plus 2 dated to early 2027.
  5. Whether the renewable megawatts are firm capacity at the building or energy procurement elsewhere. The published documents describe the second.

Renewables are not capacity

Teraco's sustainability page puts a 120MW Sediba solar project under construction with completion targeted for Q1 2027, and electricity wheeled through Eskom and municipal networks. A rooftop programme at CT1, JB5 and JB4 sits inside a commitment stated as exceeding 10MW. The first wind project is described as expected in Q3 2026; the page does not state that operation began.

None of that maps to a building's firm capacity or to any backup duration. A 120MW solar plant and a 50MW hall's resilience are different objects. Wheeled energy is a procurement and carbon question. Resilience at Omdiepte Street stays a question about switchgear, transfer schemes and diesel.

Conclusion

As of 12 November 2026, Teraco publishes enough for a buyer to check a Johannesburg campus total with a calculator and a date. That is a real disclosure standard in this market, and it deserves saying plainly.

What it does not publish is the arrangement that decides whether the 50MW in the brochure is still deliverable after a single feed failure. The megawatt is itemised to the building. The redundancy is a corporate sentence. A buyer signs both, and only one of them has been documented.

Sources checked

Every figure above is the number Teraco states, in the document cited, on the date cited. All were retrieved on 12 November 2026; the location pages and the sustainability page carry no visible publication date, and the five technical sheets linked from the campus pages did not come back.

  1. Data centre locations index — site naming and campus grouping.
  2. Johannesburg location page, JB1 to JB5 — IT-load cards 70, 14 and 50; JB2 at 24MVA with concurrent maintainability; JB4 at 80MVA.
  3. Cape Town location page, CT1 and CT2 — IT-load cards 5 and 50; white space 2,500m² and 18,000m².
  4. Durban location page, DB1 — Riverhorse Valley, 1,500m² white space, IT-load card 2.
  5. Sustainability at Teraco — 120MW Sediba solar for Q1 2027, wheeling through Eskom and municipal networks, rooftop programme above 10MW.
  6. Resilient and sustainable data centre infrastructure by design, 4 August 2025 — the verbatim N+1 distributed redundant statement.
  7. Teraco's connectivity ecosystem expands in Cape Town, 25 April 2023 — CT1 and CT2 more than 30 kilometres apart, on different power grids.
  8. Teraco completes latest expansion to hyper-connected Isando Campus, 19 August 2021 — JB3 at 29MW, Isando at 40MW.
  9. Teraco breaks ground on JB5, 7 November 2022 — 30MW development, 120MVA of utility supply.
  10. Teraco announces JB7 and a new R8 billion syndicated loan, 13 November 2024 — JB7 at 40MW, Isando up to 110MW, completion scheduled 2026, Bredell at 63MW.
  11. Teraco completes significant JB4 hyperscale expansion, 12 August 2025 — 50MW critical IT, 80MW utility, 14 halls, 17,000m², Bredell at 64MW.
  12. Teraco completes CT2 data centre expansion, 10 November 2025 — 50MW critical IT, 16 halls, 18,000m², 90MW of utility power.
  13. Teraco commences CT2 expansion, 13 November 2023 — 50MW IT load and 90MVA of utility supply at design stage.
  14. Teraco announces CT1 data centre expansion in Rondebosch, 12 November 2025 — 3MW existing plus 2MW planned for early 2027.
  15. Teraco completes Durban data centre expansion, 15 November 2023 — 4MVA utility, 2.2MW critical power, 2MW in the portfolio table.
  16. Teraco opens Riverfields hyperscale data centre, 7 August 2017 — over 24MW of power, 6,000m² of technical deployment space.
  17. Teraco in the BTW directory.

All capacity and supply figures here are publisher-stated. No independent engineering audit, metering record or utility allocation letter was reviewed.