The paper discusses the practices (currently being tested internationally) adopted by operators to cope with the evolution of the electricity system in response to the electrification of consumption and the increase in distributed renewable generation. In fact, there is an increasing demand for an adaptation of the logics and methodologies of electricity grid regulation that are more evolved than the fit&forget approach, adopted in the past by Distribution System Operators (DSOs).

For this reason, the current directives promote the adoption of more interactive planning/operation strategies with producers and consumers. In particular, European Directive 2009/72/EC introduced the concept of demand-side management to ensure the security of the electricity grid and promote the integration of renewable sources. This has led DSOs to procure flexibility services from distributed resources and implement new market rules to encourage the use of flexible load and generation.

Transmission System Operators (TSOs) are also procuring distributed resources for congestion resolution and balancing services. Therefore, it is important to coordinate the work between TSOs and DSOs to ensure alignment between the demands of different grid operators and make the best use of distribution grid resources.

The text refers to a number of reports that examine the evolving role of the DSO both as a market participant and as a neutral facilitator for the procurement of global flexibility services. The objective is to examine the current state of flexibility markets and the development of the DSO as a resource enabler for TSOs.