Energy distribution

[GRI - 302-4], [GRI - 304-2], [GRI - 305-5],



Areti manages the electricity distribution network of Rome and Formello, covering approximately 32,200 km, supplying over 2.8 million residents. In terms of volumes of electricity distributed, about 9,200 GWh in 2023, Acea is the third largest Italian operator in the sector. Table no. 56 presents the principal plant data of the Company, including the number of primary and secondary substations, the transformers191 and the km of overhead and underground distribution lines.

The environmental indicator related to protecting the territory – calculated as a percentage share of the underground high-voltage (HV) network in relation to the total of the HV lines in use (overhead and underground) –, thanks to the continuing transformation and modernisation of the high and extra-high-voltage electricity distribution grid, improved again in 2023 and stood at 50% (the ratio was 49.3% in 2022).

Table no. 56 – Number of overhead and underground distribution lines and plants (2021-2023)

systems and output
  u. m. 2021 2022 2023

High-Voltage/High-Voltage – HighVoltage/Medium-Voltage primary substations

n. 70 70 70

High-Voltage/High-Voltage and High-Voltage/Medium-Voltage transformers



169 169

transformation power





substations in use





Medium Voltage/Medium Voltage - Medium Voltage/Low Voltage transformers





transformation power





overhead and underground networks

high voltage network – overhead lines

km 275 247 241

high voltage network – underground lines

km 244 240 240

medium voltage network – overhead lines

km 420 420 420

medium voltage network – underground lines





low voltage network – overhead lines





low voltage network – underground lines





The activities defined in the Plan to modernise the high-voltage (150 kV) electricity distribution network192, which are constantly being developed, reduce the environmental impact thanks to the demolition of power lines and the removal of pylons, and help to deliver energy savings through the reconfiguration and optimisation of the HV network:

  • subsequent to the new 150 kV Selvotta – Castel Romano line coming into service, work continued on dismantling the HV lines, no longer in operation, with the removal of a total of 39 - 60 kV pylons removed from the quadrant south of Rome (LAT Laurentina-Castel Romano 1 and 2);
  • upgrading work was completed on the existing 150 kV HV Capannelle – Cinecittà/O, with the commissioning of the new 1.6 km cross linked polyethylene cable section, with the consequent decommissioning of two sets of HV cables for a total of 2.7 km.

The management of the electricity distribution network of Rome and Formello is characterized by the continuous improvement of the performance, with a particular focus on energy efficiency. Areti implements measures, such as the reclassification of medium voltage levels from 8.4 kV to 20 kV and the installation of MV/LV transformers with very low losses, which help to reduce grid losses. In 2023, grid losses amounted to about 6.2% of total issued power, improving on the figure from the previous year (6.5%). For further information see the Energy savings section in the chapter The use of materials, energy and water.

Upgrading electricity lines promotes and supports the energy transition. In this context, certain projects undertaken by Areti, such as RomeFlex, G.I.M.M.I., BeFlexible and Flow, were particularly significant. The first step in creating a local market for ancillary services to better manage the expected increase in loads on the distribution network, by actively involving customers; the second, develops a system that improves grid monitoring and maintenance; the third, tests the use of flexibility services, focusing on possible synergies between the electricity system and water system; and the fourth, tests the grid services provided by electrical cars to the electricity system, based on the use of smart charging technologies and bidirectional charging. See also the section "The Commitment to Research and Innovation" in the Institutions and Business chapter.


The PlatOne (PLATform for Operation of distribution Networks) project is funded by the European Horizon 2020 project and involves ten public-private partnerships from Italy, Greece, Belgium and Germany, with coordination by the German Aachen University. Through the companies, Areti and Acea Energia, Acea heads the Italian pilot project on Rome, in three specific areas of the capital, working with ENEA, Siemens, RSE, ENG and Apio.

The project, successfully completed in 2023 and becoming the basis for developing the RomeFlex project, introduced an innovative approach to managing the distribution grid, whilst increasing its security and stability. The ecological transition exposes urban distribution grids to a significant increase in loads, linked, among other factors, to the diffusion of electrical vehicles and heat pumps as well as an increase in distributed generation connected via medium and low voltage. This generates critical consumption and generation peaks for the grid, which in order to be better managed, require the active involvement of end users in operating the grid, based on the creation of a “local flexibility market”. The PlatOne project has tested this solution, developing a multi-platform system that can involve all market participants, and which currently forms the basis for the local flexibility market in Rome, co-managed by Areti and GME.

For the end customer, the project implements and standardises a technological solution enabling the resource and certifying all energy transactions connected to flexibility using blockchain technology.
In addition, the user is provided with an App, for interaction with the aggregator, e.g. offering the possibility to modulate loads during certain time periods. The aggregator processes the flexibility supply of its customers and sends them to the market platform, where flexibility demand of the distributor is also received, connected to grid requirements.

To access the flexibility market, it is necessary to install a second-generation meter and a device, called a Light Node, needed to receive activation commands and certify energy transfers. Furthermore, it will be necessary for both individual and aggregate customers to install devices that can modulate their production, such as storage, modular heat pumps, generators and co-generators.

The platforms and technologies developed for the PlatOne project and currently forming the basis of RomeFlex, have been shared with other national distribution system operators (DSO), who would like to use them in their own projects, in accordance with ARERA Resolution 352/2021: Unareti193 has already subscribed to RomeFlex194 and other DSOs are also expected.


The G.I.M.M.I. project (Massive and Targeted Infrastructure Inspection Management) is an innovative end-to-end solution combining satellite monitoring, artificial intelligence (AI) and drones in a single system. The satellite platform enables Areti to periodically acquire images of HV and MV overhead lines. These are processes and analysed by an algorithm using Artificial Intelligence technology that enables identification of human or plant interference. Once interference has been identified and classified on the basis of the level of severity, it is possible to launch targeted inspections using drones.

Implementation of these systems for HV and MV grids offers multiple benefits. The quick response and precision of information enable specific inspections, in place of mass cyclical inspections, thus reducing the number of inspections, increasing their efficacy and reducing working times, supporting prevention or quick resolution of outages, to the benefit of many customers and the operator. In addition, the reduced impact of motor vehicles and elimination of helicopter flights for cyclical inspections contributes to reducing CO& emissions.

The project, launched in 2021 and still in progress, involves GMatics, a start-up offering satellite monitoring and analysis services using AI algorithms, and the Milan Polytechnic, which has the task of analysing, mapping and providing indications on current and future trends for drone applications.

In 2023, the new inspection and monitoring process became standard practice and was improved with the release of the Media Data Storage platform, allowing for the filing and smart consultation of photos and videos obtained through inspections and the release of integrations between the satellite alerting system and SAP, making the intervention much more efficient.

Areti also continued its experimentation with vegetable oil transformers, launched some years ago, with the relevant characteristics and advantages shown in the information box.

Trasformatori a basso impatto ambientale

In 2023, Areti continued its experimentation with plant oil meters, an insulating liquid of plant origins (natural esters) which compared to the mineral origin oil in use, whilst having similar electrical and physical characteristics, has a higher flammability temperature, is totally biodegradable and reusable at the end of its life. To reduce the risks associated with the experimentation, the project involves three MV/LV transformers that have been custom designed and built (two at 400 kVA and the third at 630 kVA, which came into service in 2015); to date, no anomalies have been found in the transformers’ operations, with at least a 10-year term expected on an experimental basis, during which inspections and checks will be conducted on the quality of the dielectric oil. Once the results are in, an assessment will be made regarding wide-scale use.

193 Unareti is an electricity and gas distribution company in the areas of Brescia, Milan and Bergamo (only gas distribution).
194 The first RomeFlex services auction was conducted in December 2023 with considerable market success: with regard to the 2 MW flexibility required by Areti, 11 BSP (balancing service provider - aggregators) oered a total of 3.2 MW, and in respect of this amount, Areti exercised its option to collect to receive up to 50% extra capacity, contracting 3 MW of flexibility for the period February-April 2024.