Grid-Edge Energy-Flexible Technologies: A Comparative Analysis Across Generators, Loads, and Energy Storage Systems

This review analysis presents a comprehensive exploration of energy flexibility in modern power systems. It examines the roles and mechanisms of flexible technologies across three main categories: generators, energy storage systems (ESS), and loads. Energy flexibility is defined as the ability to dynamically adjust supply and/or demand in response to grid conditions to maintain balance and stability. This is of particular importance to facilitate the integration of the growing variable renewable energy sources (RES) into modern power grids. Additionally, traditional supply-side mechanisms to maintain balance and stability are complemented by advancements in demand-side management and demand response strategies, which enable loads to adjust consumption patterns and schedules in response to grid requirements. ESS are also explored to further enhance flexibility by absorbing excess generation and/or supplying large load increases that are not able to be met by the less flexible resources. This paper also explores specific flexibility technologies, examining their characteristics, control strategies, advantages, and limitations. Energy flexibility services are also categorized into intermittency mitigation, peak shaving, and energy reserve provisioning. Each service is supported by case studies and examples demonstrating how different resources respond to varying conditions. Ultimately, the findings and reviews of the various flexible resources in this paper provide a roadmap for optimizing energy flexibility across diverse resource types, paving the way for a more sustainable and resilient energy future.