Advanced Capacity Accreditation of Future Energy System Resources with Deep Uncertainties

TL;DR

This paper introduces TRACED, a novel capacity accreditation method that incorporates transmission constraints and climate factors to improve reliability assessments of renewable energy resources.

Contribution

It presents a new approach that enhances capacity credit evaluation by integrating transmission and climate considerations, addressing limitations of existing ELCC methods.

Findings

TRACED provides more accurate capacity credit allocations.

It captures resource interactions and avoids double-counting of reliability benefits.

Transmission congestion and climate trends significantly impact capacity credit allocations.

Abstract

The electric power sector has seen an increased penetration of renewable energy sources (RESs) that could strain the system reliability due to their inherent uncertainties in availability and controllability. Effective load carrying capability (ELCC) is widely used to quantify the reliability contributions of these RESs. However, existing ELCC methods can over- or under-estimate their contributions and often neglect or simplify other critical factors such as transmission constraints and evolving climate trends, leading to inaccurate capacity credit (CC) allocations and inefficient reliability procurement in capacity markets. To address these limitations, this paper proposes TRACED (TRansmission And Climate Enhanced Delta) -- an advanced capacity accreditation approach that integrates transmission constraints and climate-adjusted system conditions into a Delta ELCC evaluation. Case studies on a modified IEEE-118 bus system with high RES and energy storage penetrations demonstrate that TRACED produces portfolio-consistent CC allocations by capturing resource interactions and avoiding the double-counting of shared reliability benefits inherent in marginal ELCC, which may otherwise lead to under-procurement of reliability resources. Results further demonstrate that transmission congestion and evolving climate trends have mutual impacts on CC allocation, justifying their necessary integration into TRACED.