1. Introduction

The National Energy Regulator of South Africa (NERSA) is the statutory regulator responsible for regulating important parts of South Africa’s energy sector, including electricity, gas and petroleum pipelines. Because NERSA exercises public regulatory powers, its decisions can be challenged through administrative-law and constitutional review proceedings.

“NERSA regulatory review disputes” generally arise when an affected party argues that NERSA has exercised its statutory powers unlawfully, irrationally, procedurally unfairly, or without properly considering relevant information. Common disputes concern electricity tariffs, municipal tariff approvals, licensing, public participation, regulatory methodology, cost-of-supply assessments and the interpretation of NERSA’s statutory powers.

The central legal framework includes the National Energy Regulator Act 40 of 2004 (NERA), the Electricity Regulation Act 4 of 2006 (ERA), the Gas Act 48 of 2001, the Petroleum Pipelines Act 60 of 2003, the Promotion of Administrative Justice Act 3 of 2000 (PAJA) and the Constitution.

2. Nature of a NERSA Regulatory Review

A review is different from an ordinary appeal.

In an appeal, a court may be asked whether the regulator reached the correct substantive conclusion. In judicial review, the principal question is generally whether the decision-making process and exercise of public power were lawful, rational, procedurally fair and constitutionally compliant.

A NERSA decision may therefore be challenged where, for example:

NERSA exceeded its statutory powers;

mandatory statutory procedures were not followed;

affected persons were denied meaningful participation;

irrelevant considerations were taken into account;

relevant considerations were ignored;

the decision was irrational or unreasonable in the legally relevant sense;

NERSA relied upon an incorrect regulatory methodology;

inadequate reasons were supplied; or

the regulator acted inconsistently with constitutional or statutory obligations.

The specialised nature of NERSA's regulatory functions does not make its decisions immune from judicial review.

3. Statutory Framework

A. National Energy Regulator Act

The National Energy Regulator Act 40 of 2004 establishes NERSA as the national energy regulator and provides the institutional framework within which it exercises regulatory powers.

The Act must be read together with the sector-specific legislation administered by NERSA.

B. Electricity Regulation Act 4 of 2006

The ERA is particularly important in tariff disputes.

NERSA's electricity regulatory responsibilities include regulating electricity prices and tariffs and exercising licensing and other regulatory functions.

Section 15 of the ERA is particularly significant because it establishes principles governing electricity tariff determinations.

Consequently, a tariff decision is not simply a commercial pricing decision. It is an exercise of statutory public power and must satisfy the governing legislation.

4. Grounds Commonly Raised in NERSA Reviews

4.1 Failure to Consider Relevant Factors

A regulator cannot simply accept an application mechanically.

For example, where a utility requests a tariff increase, affected parties may argue that NERSA failed to examine:

actual operating costs;

efficiency;

prudency;

revenue requirements;

consumer impacts;

affordability;

system reliability;

wasteful expenditure;

losses;

regulatory methodology; or

other factors required by the statutory framework.

The court does not ordinarily substitute itself for NERSA merely because another methodology might have been preferable. The issue is whether NERSA's decision was legally defective.

4.2 Irrationality and Unreasonableness

NERSA's decisions must have a rational connection with:

the information before the regulator;

the purpose for which the power was given;

the statutory framework; and

the decision ultimately adopted.

This principle is especially important in technically complex tariff proceedings.

4.3 Procedural Fairness

NERSA's decisions can also be challenged because of defects in public participation or consultation.

This is particularly important for municipal electricity tariffs because tariff determinations affect consumers, businesses and municipal budgets.

A recent example is AfriForum NPC v NERSA and Others, where the Gauteng High Court dealt with the public-participation process associated with municipal electricity tariff applications. The court declared NERSA's particular implementation of its notice-and-comment process invalid and subsequently addressed the need for structured timelines governing the annual tariff process. (SAFLII)

This demonstrates that procedural legality can be just as important as the substantive tariff calculation.

5. Major Case Law

5.1 National Energy Regulator of South Africa v PG Group (Pty) Ltd

This case is important concerning the use of expert evidence and reasons in reviewing NERSA's technical decisions.

The litigation raised questions concerning economic expert reports relied upon in relation to NERSA's regulatory decision-making.

The Constitutional Court clarified an important distinction: a decision-maker cannot retrospectively manufacture reasons to justify an unlawful decision, but expert material may legitimately explain the reasoning underlying reasons that were already provided.

The case therefore illustrates the appropriate judicial approach to highly technical regulatory decisions: courts can consider specialist economic analysis without allowing the regulator to create entirely new reasons after litigation has commenced. (SAFLII)

Principle: Expert evidence may explain existing regulatory reasoning, but cannot simply replace the original reasons with an entirely new justification.

5.2 Casting, Forging & Machining Cluster of South Africa NPC v NERSA

This litigation concerned municipal electricity tariffs approved by NERSA.

The applicants challenged NERSA's tariff decision on grounds including:

irrationality;

use of inappropriate benchmarks;

failure to consider the cost of supply for particular customer categories;

absence of an adequate cost-of-supply study;

failure to comply with the Electricity Regulation Act; and

failure to comply with applicable electricity-pricing principles. (SAFLII)

The case is significant because it illustrates how regulated businesses can challenge the methodology underlying a tariff determination rather than simply objecting that the resulting tariff is too high.

An earlier stage of the dispute also concerned NERSA's approval of municipal tariffs and the consequences of that approval for electricity customers. (SAFLII)

5.3 SALGA v NERSA and Others

The South African Local Government Association challenged NERSA's approval of Eskom's bulk electricity tariff increases for the 2023/24 and 2024/25 financial years.

One argument concerned whether NERSA had adequately assessed Eskom's costs and efficiency, including concerns relating to corruption, fraud and wasteful expenditure.

The High Court ultimately refused the review applications challenging those tariff determinations. The judgment illustrates an important distinction: a party's disagreement with the regulator's methodology or outcome does not automatically establish a reviewable error. (SAFLII)

The subsequent application for leave to appeal was also refused. (SAFLII)

5.4 AfriForum NPC v NERSA and Others

This is particularly important for procedural review.

The dispute concerned NERSA's public-participation process for municipal electricity tariff applications for 2025/26.

The High Court found the implementation of the relevant notice-and-comment procedure invalid. It subsequently considered whether the court could impose a structured timetable to ensure that NERSA, Eskom and municipalities perform their respective functions in sufficient time for municipal budget processes and meaningful public participation. (SAFLII)

The case is significant for three reasons:

public participation is legally important;

regulatory delay can itself have constitutional and administrative-law consequences; and

judicial remedies can sometimes include structured or supervisory relief rather than merely setting aside a decision.

5.5 Mpact v Ekurhuleni Metropolitan Municipality and NERSA

A 2026 High Court decision illustrates the continuing importance of NERSA tariff-review disputes.

The applicants challenged tariffs for the 2024/25 and 2025/26 financial years while also facing possible termination of electricity supply. The case addressed the interaction between NERSA's tariff approval, municipal credit-control powers and pending review proceedings. (SAFLII)

The litigation demonstrates a practical issue: even where a NERSA decision is under review, regulated tariffs can have immediate consequences for customers and municipalities.

It also reinforces the importance of the Oudekraal principle, under which an administrative decision generally continues to have legal effect until it is properly set aside by a competent court.

5.6 NERSA v Senwes Ltd

The litigation involving Senwes concerns a challenge to NERSA's approval of a municipal electricity tariff policy.

The 2024 judgment dealt, among other things, with procedural issues surrounding the progress of the review proceedings and NERSA's participation in the litigation. The underlying review sought to challenge NERSA's approval of the municipality's tariff policy. (SAFLII)

The case demonstrates that NERSA regulatory litigation can involve complicated procedural questions, including joinder, condonation, delays and the management of review proceedings.

6. Judicial Deference to NERSA

Because NERSA is a specialist regulator, courts recognise that it possesses technical expertise that courts generally do not possess.

The principle of judicial deference therefore has considerable importance.

Courts are generally cautious about replacing the regulator's technical or policy judgment with their own. The principle is particularly relevant where the dispute concerns:

economic modelling;

electricity pricing;

cost allocation;

engineering considerations;

market regulation;

technical licensing conditions; or

specialist regulatory methodologies.

However, deference is not immunity.

The regulator must still act within the powers Parliament has given it and comply with constitutional and administrative-law requirements. The AfriForum litigation specifically considered this tension between specialist regulatory discretion and judicial supervision. (SAFLII)

7. NERSA Tariff Decisions and the Oudekraal Principle

A particularly important practical rule is that an administrative decision generally remains legally operative until properly reviewed and set aside.

Thus, a consumer or municipality cannot necessarily treat a disputed NERSA tariff as automatically invalid merely because review proceedings have been instituted.

The 2024 Casting, Forging litigation concerning City Power tariffs illustrates this issue. The court considered the argument that NERSA-approved tariffs remain operative until set aside, even where their legality is being challenged. (SAFLII)

This has significant consequences because municipalities may continue billing customers according to approved tariffs while review litigation is pending.

8. Available Judicial Remedies

Where a court identifies a reviewable defect, several remedies may be possible.

A. Setting Aside

The court may declare the NERSA decision invalid and set it aside.

B. Remittal

The matter may be returned to NERSA for reconsideration.

This respects the regulator's institutional role because NERSA, rather than the court, may be better placed to make the substantive regulatory determination.

C. Declaratory Relief

A court may clarify the legal meaning of NERSA's statutory powers or obligations.

D. Interdicts

Where implementation creates immediate harm, interim or final interdictory relief may be sought.

E. Structural or Supervisory Relief

In exceptional circumstances, courts may prescribe procedural timelines or require further reporting and compliance.

The AfriForum litigation is an important example of this form of judicial supervision in the NERSA context. (SAFLII)

9. Relationship Between PAJA and Legality

NERSA exercises public power. Consequently, its decisions may be examined under PAJA where the requirements for administrative action are satisfied.

Relevant concerns include:

lawfulness;

procedural fairness;

reasonableness;

rationality;

relevant and irrelevant considerations;

adequate reasons; and

compliance with empowering legislation.

Where PAJA does not provide the applicable route, the constitutional principle of legality remains important.

Thus, NERSA cannot exercise powers merely because they appear administratively convenient. The power must be traceable to a lawful source.

10. Importance for Energy Governance

NERSA regulatory-review disputes perform several broader functions.

Accountability

Judicial review provides external scrutiny of an independent regulator.

Regulatory certainty

Courts clarify the boundaries of NERSA's statutory powers.

Consumer protection

Review proceedings can examine whether tariff processes properly account for affected consumers and other stakeholders.

Institutional autonomy

At the same time, judicial review must avoid transforming courts into substitute energy regulators.

Transparency

Tariff decisions involve large financial consequences. Proper reasons and transparent methodologies therefore become central to regulatory legitimacy.

Constitutional governance

NERSA's technical responsibilities operate within the constitutional principles of legality, accountability, participation and rational public administration.

11. Conclusion

NERSA regulatory review disputes represent the intersection of energy regulation, administrative law and constitutional governance. The courts generally recognise NERSA's specialist expertise, particularly in technically complex tariff and economic matters, but that expertise does not exempt NERSA from judicial scrutiny.

The principal review questions are whether NERSA:

acted within its statutory powers;

followed the prescribed procedure;

provided meaningful participation where required;

considered relevant information;

avoided irrelevant considerations;

reached a rational decision on the information before it;

provided legally adequate reasons; and

complied with constitutional and administrative-law requirements.

Cases such as NERSA v PG Group, Casting, Forging & Machining Cluster v NERSA, SALGA v NERSA, AfriForum v NERSA, and NERSA v Senwes demonstrate different dimensions of this review jurisdiction. (SAFLII)

The underlying legal balance is therefore between regulatory expertise and judicial legality review: NERSA retains its specialised decision-making role, but its exercise of public power must remain lawful, rational, procedurally fair, transparent and accountable.