Mulilo vs NTCSA: What the April 9 Hearing Signals for C&I Grid Access in the Northern Cape

On 9 and 10 April 2026, a Johannesburg High Court bench will hear the substantive application in Mulilo Renewable Energy v Eskom Holdings SOC Ltd and Others — a case that has already reshaped how South Africa's energy sector thinks about grid access rights. For commercial and industrial (C&I) energy buyers, this is not utility-scale background noise. The structural questions this case forces into the open are the same ones quietly determining whether your next solar PPA or wheeling arrangement is commercially viable, bankable, or simply stranded.

What the Case Is Actually About

The litigation is precise in its facts. Mulilo's "Nepal" solar PV project had 240 MW of transmission capacity reserved at a substation in the Northern Cape. Eskom subsequently attempted to cancel that reservation and reallocate the capacity to three Scatec-linked Bid Window 7 projects — Leeuwspruit Solar 1, Oslaagte Solar 2, and Oslaagte Solar 3. Mulilo went to court arguing that the cancellation was unlawful, that its grid access approval from Eskom and NTCSA remained valid, and that it had not been given adequate due process.

Following a hearing in late 2025, the High Court granted Mulilo an interim interdict on 5 December 2025, restraining Eskom and NTCSA from using the disputed capacity. Eskom has since applied for leave to appeal that interdict — arguing the ruling could have far-reaching implications for both public and private procurement programmes — but leave to appeal has not yet been granted. The interim interdict remains in force. The hearing of the substantive Part B application has been brought forward and set down for 9 and 10 April 2026, with the court directing it be heard no later than 30 June 2026.

Eskom's defence rests on a single regulatory hook: that Mulilo failed to register its Nepal project with NERSA within the required timeframes, causing the grid reservation to lapse. Mulilo disputes this. And therein lies the problem that extends well beyond these two parties.

The Regulatory Grey Zone at the Heart of the Dispute

The case has exposed a structural ambiguity that C&I developers and their off-takers need to understand. Privately procured projects must be registered with NERSA, while publicly procured REIPPPP projects require a generation licence — but the timing and sequencing of these processes are not always clearly defined. This lack of clarity is central to the dispute, and it is not unique to Mulilo.

Developers across the sector have raised concerns about uncertainty in grid access allocation processes, inconsistent application of project milestone requirements, and the real risk of losing grid reservations due to regulatory delays entirely outside their control. When hundreds of millions of rands in project investment hinge on whether a NERSA registration timestamp was met, and the rules governing that deadline are opaque, litigation is the inevitable result.

The lesson the sector is learning in real time: building a solar plant in the Northern Cape is operationally achievable. Securing and defending the transmission access to export that power is the harder commercial problem.

Why the Northern Cape Is Ground Zero

The Mulilo dispute did not emerge randomly. The Northern Cape is simultaneously South Africa's richest solar resource corridor and its most constrained transmission corridor. Key regions — particularly the Northern Cape and parts of the Free State — are approaching grid saturation, with applications for grid access now exceeding available capacity in some areas while transmission expansion has lagged well behind generation ambition.

South Africa's congestion curtailment framework, approved by NERSA in April 2025, unlocked approximately 3,470 MW of capacity — but primarily in the Western Cape (2,680 MW) and Eastern Cape (790 MW). That relief has not meaningfully reached the Northern Cape. Expanding the curtailment framework to additional provinces requires separate NERSA approval, and that process is ongoing. The result: Northern Cape transmission corridors remain severely constrained, with several gigawatts of wind and solar projects effectively stranded.

The irony is acute. The province with the highest solar irradiance in South Africa — reaching up to 3,200 kWh/m² annually — is the province where grid access is most fiercely contested and least available. For C&I developers eyeing the Northern Cape for large-scale private generation, this case is a direct signal that grid reservation is now a critical commercial asset requiring legal-grade protection, not just a technical approval step.

The NTCSA's Role — and Its Unresolved Transition

NTCSA sits uncomfortably at the centre of this dispute. South Africa is mid-transition towards a more independent Transmission System Operator: NTCSA was legally separated from Eskom as a subsidiary in 2024, and President Ramaphosa's February 2026 SONA confirmed the intention to transition NTCSA into a fully standalone TSO, supported by a dedicated NECOM task team. The 14,000 km Transmission Development Plan is intended to address grid constraints and unlock renewable energy corridors.

But the Mulilo case lands exactly during that transition, when NTCSA has a strengthened interim mandate but is not yet a fully certified independent operator. The Market Code — which governs grid access methodologies, use-of-system charges, and participation rules — is entering phased implementation from April 2026, with full market functionality targeted by 2031. SAWEM, the South African Wholesale Electricity Market, was targeted for a phased launch from 1 April 2026 through Eskom power stations and publicly procured IPPs first, before broader private sector participation opens up.

Confidence in NTCSA's fairness and independence as an allocator of transmission access is therefore not just a legal question — it is a structural precondition for South Africa's electricity market reform. If grid allocation decisions can be reversed without clear, transparent due process, investor confidence erodes in precisely the moment it is most needed.

What This Means for C&I Solar and Wheeling Projects Right Now

For CFOs and operations directors evaluating commercial solar investments — particularly those involving wheeling, private wire, or off-site generation — the April 9 hearing carries four concrete implications:

• Grid access approval is not a formality — it is a legal right requiring active management. Mulilo's case turns on whether a grid reservation was procedurally maintained. Any C&I project relying on wheeled generation must treat NERSA registration timelines and grid access documentation as a project-critical compliance track, not an afterthought.
• Northern Cape generation capacity for new private projects remains effectively constrained. For businesses evaluating off-site generation in the Northern Cape, the capacity picture has not fundamentally changed. Projects with existing grid reservations carry premium value; new applicants face a queue with no guaranteed outcome.
• Behind-the-meter solar and on-site BESS remain the most insulated commercial option. Projects that do not require transmission access — roof-mounted or ground-mounted solar with battery storage co-located at the point of consumption — bypass this entire class of risk. For C&I properties with available roof or land, this is a meaningful structural advantage of the behind-the-meter model.
• The SAWEM transition creates both opportunity and complexity for wheeling PPAs. As SAWEM's phased Market Code implementation begins, the framework for private wheeling is evolving. C&I off-takers entering long-term wheeling PPAs now need to ensure those agreements are structured to accommodate SAWEM's balancing requirements, use-of-system charges, and the eventual move to system-marginal pricing. Older PPA structures that did not anticipate this transition may face renegotiation pressure.

The Precedent That Will Be Set

The High Court's ruling — expected within the window the court itself has set, no later than 30 June 2026 — will be the first substantive judicial test of under what circumstances Eskom or NTCSA may cancel a previously granted grid reservation. If the court finds that cancellation requires clearer procedural standards than currently exist, it will likely force NERSA and NTCSA to codify more explicit, transparent rules. That is a long-term positive for the sector.

If Eskom's position prevails, it signals that grid reservations for privately procured projects are substantially more fragile than the market has assumed — and that the balance of allocation power remains with the system operator, not the developer. Either outcome will reverberate through every active wheeling negotiation and large-scale C&I solar project currently in development.

At SolarXgen, our view is straightforward: the transmission constraint is real, the regulatory framework is still maturing, and waiting for resolution before making energy investment decisions is not a commercial strategy. Behind-the-meter solar and co-located BESS deliver guaranteed, grid-independent savings today. For businesses that need scale beyond the fence line, the structured approach is to engage now — with proper legal and regulatory diligence baked into project structuring from day one.