RISK-ADJUSTED RESERVE ADEQUACY PRICING

1. Concept and Purpose

Risk-adjusted reserve adequacy pricing is a regulatory and market mechanism through which electricity systems determine the economic value of maintaining sufficient dependable generation, storage, demand response, and other flexible resources to meet demand during periods of system stress. Unlike ordinary energy pricing, which compensates electricity actually produced, reserve-adequacy pricing compensates resources for being reliably available when shortages may occur.

The “risk-adjusted” element means that capacity is not valued purely according to installed megawatts. Regulators consider outage probabilities, demand uncertainty, renewable intermittency, transmission constraints, extreme weather, correlated failures, and the probability of electricity shortages. Capacity with greater dependable contribution may therefore receive greater recognition than capacity whose availability is uncertain.

Capacity markets are designed to ensure future electricity requirements can be met while balancing reliability and consumer cost. FERC similarly describes capacity markets as payments for the ability to provide electricity when required rather than payment for electricity actually generated.

2. Risk-Adjusted Pricing Methodology

Reserve adequacy normally begins with a legally or administratively established reliability standard. System operators forecast peak demand and calculate how much dependable capacity is necessary to satisfy that standard.

Important measures include:

Loss of Load Expectation (LOLE): estimates the expected frequency of supply insufficiency.

Expected Unserved Energy (EUE): estimates the quantity of electricity demand that may remain unmet.

De-rating factors: reduce the nominal capacity of technologies according to their expected availability during system stress.

Cost of New Entry (CONE): estimates the annual revenue required to support new dependable capacity.

Value of Lost Load (VoLL): represents the economic cost associated with involuntary electricity interruption.

These variables allow the reserve price to reflect both the probability and economic consequences of scarcity.

Great Britain provides a practical illustration. The Capacity Market seeks sufficient reliable capacity to satisfy a reliability standard of three hours LOLE. For the 2030/31 T-4 auction, the July 2026 parameters specify a 40.9 GW target, £49/kW/year net CONE and a £75/kW/year price cap.

3. Legal and Regulatory Issues

Risk-adjusted adequacy pricing must comply with principles of transparency, proportionality, technological neutrality, competition and non-discrimination. Rules that systematically undervalue storage, demand response or renewable resources may distort competition.

Regulators must also prevent excessive capacity procurement. Over-procurement transfers unnecessary costs to consumers, whereas under-procurement increases blackout risk. Capacity-market rules therefore regulate qualification, auctions, capacity obligations, penalties and performance requirements. The UK Capacity Market Rules provide this detailed operational framework.

4. Case Law

Tempus Energy Ltd and Tempus Energy Technology Ltd v European Commission, Case T-793/14, ECLI:EU:T:2018:790

Facts: Tempus challenged the European Commission's approval of the United Kingdom Capacity Market, arguing principally that demand-side response had not been adequately considered and that the Commission should have conducted a formal State-aid investigation.

Legal Issue: Whether approval of a capacity-remuneration system without a formal investigation sufficiently addressed competition and State-aid concerns.

Judgment: The General Court annulled the Commission's decision in 2018 because circumstances indicated doubts requiring a formal investigation. The Court of Justice subsequently set aside that judgment in European Commission v Tempus Energy, Case C-57/19 P (2021).

Legal Principle/Ratio: Capacity mechanisms must be evaluated under State-aid and competition rules, but the existence of different treatment or complex market design does not automatically establish sufficient doubts requiring formal investigation.

Significance: The litigation demonstrates that adequacy pricing must be justified through objective reliability assessments while appropriately considering alternative capacity resources such as demand response.

Hughes v Talen Energy Marketing LLC, 578 U.S. 150 (2016)

Facts: Maryland required a generator to participate in PJM's federally regulated capacity auction while guaranteeing it a separate contractual revenue level.

Legal Issue: Whether a state could effectively alter compensation resulting from the FERC-regulated wholesale capacity auction.

Judgment: The US Supreme Court held that the Maryland programme was pre-empted because payment was conditioned upon the generator clearing the PJM auction.

Legal Principle/Ratio: States retain significant authority over generation policy, but they cannot directly disregard or replace federally regulated wholesale capacity prices.

Significance: Reserve-adequacy pricing therefore involves not merely economic risk modelling but also strict allocation of regulatory jurisdiction.

5. Conclusion

Risk-adjusted reserve adequacy pricing converts reliability risk into an economic signal. By combining probabilistic adequacy standards, de-rating, scarcity valuation, competitive procurement and performance obligations, electricity law seeks to procure sufficient dependable capacity without imposing excessive consumer costs. Its legality ultimately depends upon transparent methodology, competitive neutrality, proportionality and respect for regulatory jurisdiction.