Fast frequency control ancillary services: An international review

This paper describes the frequency control ancillary services (FCAS) that value the response speed of the frequency control resources and/or can only be provided, without curtailing available renewable energy, by inverter-coupled generation or storage technologies, which have, to date, been implemented or proposed all over the world. These services are referred to in the paper as fast frequency control ancillary services (FFCAS). The paper describes, among others, the following characteristics of the identified FFCAS: maximum response time, minimum time during which the response must be sustained, markets (if any) in which the agents can/must submit bids to provide the service, characteristics of the offers, whether the service is remunerated for the reserved capacity and/or the energy delivered, whether or not the service payment is performance-based, formulas used to determine the service payment, whether or not there exists a specific regulation signal for fast-acting resources, evolution of the service price. In addition, the paper describes a few FCAS which, though cannot be strictly speaking considered FFCAS, have a particularly demanding response time requirement.