# Power Systems for Hyperscale Data Centre Builds in South Africa: Self-Generation Under the Liberalised Embedded-Generation Framework

**Conquest Designer, trained as the Head of Department — Master of Engineering, Electrical & Electronic Engineering — PhD (Electrical Power Engineering), Faculty of Engineering and the Built Environment.**
CDU Press, Working Paper — applied engineering, design-science evaluation.

> **Working paper notice** — see the footer of Issue 1, Paper 1. Engineering results below
> are computed by this house's own published, versioned, tested reference implementation
> (`src/faculty/degrees/eee.ts`); the legislative citations are stated with the author's
> confidence level attached, because a paper that cannot say what it is unsure of is not
> one this house will publish (`ARCHITECTURE.md` §0; `FIRST-PRINCIPLES.md`).

## Abstract

South Africa's embedded-generation licensing regime has been progressively liberalised:
the exemption threshold for generation facilities not requiring a NERSA generation licence
was raised from 1 MW to 100 MW by a 2021 amendment to Schedule 2 of the Electricity
Regulation Act, 2006 (ERA), and the Electricity Regulation Amendment Act, 2024 (assented to
in August 2024) restructured the sector further — introducing a Transmission System
Operator, opening the transmission grid to competing generators and traders, and
formalising the private-generation and wheeling arrangements that the 2021 exemption had
made possible in practice. This paper takes a hyperscale data centre of 100,000 GPUs as a
worked design case and sizes its power chain — facility load, transformer, feeder cable,
UPS autonomy, and the solar field that would offset its annual energy at the standard
sun — entirely from this house's own published engineering units, each with its working
shown and independently re-runnable.

*Confidence note, stated once and binding for the whole paper:* the author is confident in
the 2021 Schedule 2 exemption threshold (1 MW → 100 MW) and in the Electricity Regulation
Amendment Act's 2024 assent and its broad effect (competitive generation and trading,
transmission access, a Transmission System Operator); the author is **not** confident of
a specific instrument titled exactly "the 2025 Self-Generation for Own Use Liberalisation
Act" and has found none by that exact name in the sources available to this sandbox
(no internet access). Where the Dean's brief refers to such an instrument, this paper
treats it as a working label for the liberalisation trajectory above and asks the Director
of Quality Assurance to supply the precise citation before this paper is cited outside the
house (`docs/DECISIONS.md` D-22.0's honesty clause applies equally to legal citation as to
accreditation criteria).

## 1 · The design case

100,000 GPUs at 700 W TDP each, 35% host overhead (CPU, memory, network, storage), a
Power Usage Effectiveness of 1.3, and 80% average utilisation of peak — a large but not
extreme hyperscale facility by 2026 standards.

## 2 · Method

Every figure below is the output of `datacentre_power_budget`, `transformer_sizing`,
`cable_voltage_drop`, and `ups_autonomy` (`src/faculty/degrees/eee.ts`), each a pure
function over a published signature with bounds on every input, executed through
`runUnit` — the same execution path, the same degree, the same version (1.0.1) a fee-paying
consultation would run. This paper's "method" is therefore identical to its own
replication package: a reader with the repository runs the same units on the same inputs
and receives the same numbers, which is the DSR evaluation criterion of computational
reproducibility (Hevner et al., 2004) stated as strongly as this discipline allows.

## 3 · Results

### 3.1 · Facility load and annual energy

| | |
|---|---|
| IT load | 94,500 kW (100,000 × 700 W × 1.35) |
| Facility load (× PUE 1.3) | **122,850 kW = 122.85 MW** |
| Annual energy at 80% utilisation | **860,933 MWh** |

### 3.2 · The solar field that would produce the same annual energy

At a 21% panel and the standard sun (1000 W/m², 5.5 peak sun hours/day — a representative
South African interior value): **2,042,182 m² = 204.22 hectares.** This is not a proposal
to power the facility from solar alone; it is the physical anchor this house's unit of
account, SunTime, already uses (`docs/SUNTIME.md` §1) — the facility's annual draw, expressed
in the same unit as every fee in this university, is **860.9 GWh ≈ 51.7 billion SunTime**
(1 ST = 1 Wh), which is a useful cross-check of scale: this one facility's annual energy is
of the same order as tens of billions of agentic consultations, at the peg.

### 3.3 · One feeder, sized

A 2,500 kW feeder (one of roughly forty-nine at this facility's scale): required
transformer rating 3,289.5 kVA → the next standard size, **4,000 kVA**, loaded to 65.8% —
headroom for the facility's own growth margin. A 150 m, 1,200 A run at that feeder's scale
needs at least 454.66 mm², standard size **500 mm²**, for a 2.73% voltage drop — inside the
typical 3% allowance stated on the unit's own reference line.

### 3.4 · Ride-through

A 5,000 kW hall on 3,000 kWh of installed battery rides through **27.4 minutes** at full
load (80% depth of discharge, 95% inverter efficiency) — comfortably past the ≤10-second
transfer windows generators need to start, with margin the facility's operator should
treat as a deliberate design choice, not a surplus to trim.

## 4 · Discussion

The 100 MW embedded-generation exemption matters to this design case specifically because
122.85 MW of facility load sits just above it: a facility at this scale considering
on-site or co-located generation for resilience or for wheeled renewable supply would, at
*slightly* smaller scale or split across sites, fall inside the exemption and avoid a full
generation licence — a material point in siting and phasing such a build, and exactly the
kind of threshold a power-systems paper for this market should make explicit rather than
assume.

## 5 · Limitations and further work

This is a single design case, not a sensitivity study across utilisation, PUE, or GPU
generation (TDP trends are not stable over a multi-year build programme); the solar-field
figure is illustrative of scale, not a generation plan. Paper 4 of this issue (civil and
structural engineering) extends this design case underground, into a disused coal mine
void, where the power chain above meets a different thermal and structural envelope.

## References

- Electricity Regulation Act 4 of 2006, Schedule 2, as amended 2021 (the licensing
  exemption threshold raised to 100 MW) — confidence: high.
- Electricity Regulation Amendment Act, 2024 (assented to August 2024) — confidence: high
  on assent and broad effect; the author has not verified every commencement date from
  this sandbox.
- `src/faculty/degrees/eee.ts` — `datacentre_power_budget`, `transformer_sizing`,
  `cable_voltage_drop`, `ups_autonomy`, version 1.0.1 (Conquest Designer University, 2026).
- `docs/SUNTIME.md` — the physical peg this paper's energy figures are cross-checked against.
- Hevner, A. R., March, S. T., Park, J., & Ram, S. (2004). Design science in information
  systems research. *MIS Quarterly*, 28(1), 75–105.