MINUTE-BY-MINUTE MARKET SETTLEMENT REGULATION

1. Meaning and Concept

Minute-by-minute market settlement regulation refers to a highly granular electricity-market framework in which generation, consumption, imports, exports and balancing deviations are measured and financially settled at intervals approaching individual minutes. Although many electricity markets presently use longer settlement periods, minute-level settlement represents an advanced regulatory model designed for systems dominated by renewable energy, batteries, demand response, smart meters and automated electricity trading.

Settlement converts physical electricity flows into legally enforceable financial obligations. Shorter intervals can therefore align market payments more closely with actual system conditions and the real-time value of electricity.

2. Regulatory Objectives

The principal objective is temporal accuracy. Electricity cannot ordinarily be economically stored throughout the network in the same manner as conventional commodities, so generation and demand must continuously remain balanced.

Long settlement intervals can average substantial short-term variations. Minute-level settlement reduces this averaging effect and can expose market participants to the financial consequences of their actual short-duration imbalances.

Its principal regulatory purposes include accurate price formation, balancing discipline, efficient dispatch, renewable integration and improved incentives for flexibility.

3. Metering and Data Obligations

Minute-level settlement depends upon sophisticated metering infrastructure. Generators, suppliers, storage operators and eligible consumers may be required to maintain meters capable of recording electricity flows at sufficiently granular intervals.

Market rules must specify meter accuracy, calibration, validation, data retention, estimation and correction procedures. Where measurements are missing or corrupted, predetermined substitution methodologies are necessary because settlement cannot depend upon arbitrary reconstruction.

The enormous quantity of information generated also creates obligations concerning cybersecurity, privacy, data governance and interoperability.

4. Calculation of Imbalances

Each market participant generally has a scheduled or contracted position. Actual electricity generation or consumption is compared against that position for the relevant settlement interval.

Where a generator produces less than its committed quantity, it may create a negative imbalance. Conversely, additional generation or reduced consumption can create a positive imbalance. Settlement rules determine the applicable imbalance price and resulting payment.

Minute-level calculation makes these consequences significantly more precise. It particularly benefits flexible resources such as batteries that can respond within seconds or minutes to system conditions.

5. Regulatory Fairness and Transparency

Granular settlement must remain transparent and non-discriminatory. Market participants need advance knowledge of the settlement algorithm, reference prices, imbalance methodology, correction procedures and dispute mechanisms.

Regulators must also consider proportionality. Small generators and distributed-energy participants may face excessive compliance costs if sophisticated metering and data obligations are imposed uniformly.

Accordingly, exemptions, aggregation mechanisms or simplified settlement arrangements may sometimes be necessary.

6. Case Law: National Energy Regulator of South Africa v PG Group

Case Name/Citation: National Energy Regulator of South Africa and Another v PG Group (Pty) Ltd and Others [2019] ZACC 28; 2020 (1) SA 450 (CC).

Facts: NERSA adopted methodologies and decisions governing maximum gas prices and transmission tariffs. Regulated entities challenged aspects of those decisions under administrative law.

Legal Issue: Whether specialised regulatory methodologies and resulting decisions complied with the requirements of lawful administrative action.

Judgment: The Constitutional Court examined the regulatory decisions under the Promotion of Administrative Justice Act 3 of 2000 (PAJA) and considered whether NERSA had exercised its statutory regulatory powers lawfully.

Legal Principle/Ratio Decidendi: Technical economic regulation remains subject to legality, rationality and administrative-law review. Regulatory expertise does not place complex methodologies beyond judicial scrutiny.

Significance: Applied to minute-by-minute settlement, the case indicates that sophisticated algorithms and pricing methodologies must have statutory authority, rational foundations and procedurally lawful implementation.

7. Case Law: National Energy Regulator of South Africa v Borbet SA

Case Name/Citation: National Energy Regulator of South Africa v Borbet SA (Pty) Ltd and Others 2017 (5) SA 358 (SCA).

Facts: Large electricity users challenged NERSA's approval of Eskom's tariff-related regulatory decisions, including the treatment of revenue requirements within the applicable methodology.

Legal Issue: Whether NERSA had acted consistently with its governing statutory and regulatory framework when making the tariff decision.

Judgment: The Supreme Court of Appeal scrutinised the regulator's exercise of statutory power and the legal basis underlying the disputed determination.

Legal Principle/Ratio Decidendi: Electricity pricing decisions must remain connected to the statutory framework and applicable regulatory methodology.

Significance: Minute-level settlement similarly cannot operate solely as a technical calculation. Settlement formulas ultimately determine financial rights and liabilities and therefore require clear legal authority and consistent regulatory application.

8. Algorithmic Settlement and Dispute Resolution

Automation would be essential where millions of minute-level measurements are processed daily. Market operators could automatically calculate deviations, balancing prices and payments.

Nevertheless, automated decisions require audit trails and correction procedures. Participants should be capable of challenging inaccurate meter readings, erroneous algorithms or improper settlement calculations. Regulators must also supervise potential market manipulation involving rapid bidding or strategic battery dispatch.

9. Conclusion

Minute-by-minute market settlement represents an advanced form of real-time electricity-market regulation. It can improve price accuracy, flexibility incentives, renewable integration and balancing discipline. However, its legitimacy depends upon reliable metering, transparent algorithms, secure data systems, proportional compliance requirements and accessible dispute procedures. South African regulatory jurisprudence demonstrates that even highly technical market mechanisms remain governed by statutory authority, rationality, transparency and administrative justice.