"Q" as in Quality of the transmission service

The quality of the electricity transmission service refers to the ability to ensure the continuity of the electricity supply and the respect of adequate voltage and frequency standards over time.

This is an area of increasing importance due to the growing electrification of consumption, making continuous service availability essential. This is also due to the increasing presence of electronic components for the automation of plants, especially industrial plants, which require high quality supply.

Quality of service is defined in relation to continuity of service, i.e. the absence of interruptions in the provision of high-voltage electricity, and voltage quality, i.e. the maintaining of technical parameters for voltage and frequency of supply to consumers within established limits.

Various indicators defined by regulators are used to measure this capacity.

The service continuity indices can be divided into indices based on an incentive mechanism provided for in the TIQ.TRA (Integrated Text for Output-Based Transmission Service Regulation) and additional indices monitored by Terna in accordance with Chapter 11 of the Grid Code and related annexes.

Voltage quality indices are defined in Chapter 11 of the Italian Grid Code and are processed via ad hoc data analysis, recorded at various nodes of the high voltage (HV) grid, selected to ensure samples are as representative as possible.

Analysis of quality indices is one of the most effective tools to efficiently target development actions, with the goal of preventing and reducing the duration of consequences associated with grid outages.

In the context of an energy transition towards environmentally sustainable sources, maintaining the quality of service at the current high levels is, and will continue to be, one of the key challenges Terna will face as the Italian electricity grid operator.