Maximizing Power Flexibility of Hybrid Energy Systems for Capacity Market

TL;DR

This paper introduces a rule-based framework to quantify and allocate power flexibility in hybrid energy systems, enhancing their participation in capacity markets by addressing renewable uncertainty and operational constraints.

Contribution

It presents a systematic method for characterizing HES flexibility, real-time power allocation, and benchmarking against optimal dispatch, with a focus on practical implementation.

Findings

The flexibility envelope accurately captures HES power boundaries.

The proposed allocation protocol supports reliable market participation.

Benchmarking shows near-optimal performance under realistic conditions.

Abstract

Hybrid Energy Systems (HES), integrating generation sources, energy storage, and controllable loads, are well-positioned to provide real-time grid flexibility. However, quantifying this maximum flexibility is challenging due to renewable generation uncertainty and the complexity of power allocation across multiple assets in real time. This paper presents a rule-based framework for characterizing HES flexibility and systematically allocating power among its constituent assets. The flexibility envelope defines the dynamic power boundary within which the HES can inject or absorb power without violating operational constraints. Shaped in real time by capacity bids, available solar generation, and power allocation protocol, it enables reliable and predictable HES participation in regulation markets. Depending on the operational objective, the framework supports both symmetric and asymmetric flexibility cases. Further, the proposed power-allocation rule is benchmarked against an optimal dispatch, providing a performance reference under realistic conditions. Finally, state of charge drift correction control is presented to ensure sustained battery operation and system reliability. This work, therefore, offers a rigorous and practical framework for integrating HES into capacity markets through effective flexibility characterization.