Market Implications of Alternative Operating Reserve Modeling in Wholesale Electricity Markets

TL;DR

This paper examines how different models of reserve constraints in U.S. wholesale electricity markets significantly influence prices, reserve levels, and revenues, highlighting the importance of modeling choices for market outcomes.

Contribution

It introduces and compares four alternative reserve constraint models in a synthetic power system, revealing their distinct impacts on market prices and revenues.

Findings

Model variations cause substantial differences in market prices.

Reserve quantities and revenues are highly sensitive to constraint modeling.

Market simulations demonstrate the economic significance of modeling assumptions.

Abstract

Pricing and settlement mechanisms are crucial for efficient re-source allocation, investment incentives, market competition, and regulatory oversight. In the United States, Regional Transmission Operators (RTOs) adopts a uniform pricing scheme that hinges on the marginal costs of supplying additional electricity. This study investigates the pricing and settlement impacts of alternative reserve constraint modeling, highlighting how even slight variations in the modeling of constraints can drastically alter market clearing prices, reserve quantities, and revenue outcomes. Focusing on the diverse market designs and assumptions in ancillary services by U.S. RTOs, particularly in relation to capacity sharing and reserve substitutions, the research examines four distinct models that combine these elements based on a large-scale synthetic power system test data. Our study provides a critical insight into the economic implications and the underlying factors of these alternative reserve constraints through market simulations and data analysis.