Discover the Acea Group online 2019 Sustainability Report

Energy distribution


Areti manages the electricity distribution network of Rome and Formello, extending over about 31,000 km and capable of supplying about 2.8 million resident inhabitants. In terms of volumes of electricity distributed, about 9,830 GWh in 2019, Acea is the third largest Italian operator in the sector.

In table no. 49 the principal plant data of the Company are described, including the number of primary and secondary substations, the transformers108 and the km of overhead and underground distribution lines.

The environmental indicator related to the protection of the region, calculated as a percentage share of the underground high voltage grid (HV) in relation to the total of the HV lines in use (overhead and underground), has improved in recent years, and in 2019 was stable compared to the previous year, equal to 46% (44% in 2017). This also as a result of the ongoing transformation and modernisation of the high and very high voltage electricity distribution grid.


SYSTEMS AND OUTPUTm.u.201720182019
High Voltage/High Voltage – High Voltage/Medium Voltage primary sub-stationsno.717070
High Voltage/High Voltage and High Voltage/Medium Voltage transformersno.169166170
transformation powerMVA7,9217,6317,781
sub-stations in useno.13,15913,21113,238
Medium Voltage/Medium Voltage – Medium Voltage/Low Voltage transformersno.12,83212,83812,883
transformation powerMVA6,2036,2366,282
high voltage network – overhead lineskm310282282
high voltage network – underground lineskm243243243
medium voltage network – overhead lineskm419424422
medium voltage network – underground lineskm10,13710,16610,470
low voltage network – overhead lineskm1,6411,6411,642
low voltage network – underground lineskm18,14718,30618,417

With reference to the electric and magnetic fields, in particular related to the primary transformer substations, High and Medium Voltage overhead electricity lines and secondary transformer stations, the possible risks for the health of employees and the community of reference are dealt with, respectively, in the Risks Evaluation Document and in the Corporate Environmental Analyses Document. Areti conducts periodic sample checks in the company’s sites, carried out also following reports by users/customers or External Bodies. Additional checks are conducted by ARPA Lazio109 following specific requests by the public and customers.


2019 saw the continuation of the plan to modernize the high voltage electricity distribution network (150 kV), defined in the Memorandum of Understanding signed in 2010 among Areti SpA (formerly Acea Distribuzione), the Municipality of Rome and Terna SpA. In particular, during the following activies were carried out:

  • continuation of the demolition of the 150 kV Flaminia 2 – East Sorting 2 line, for a length of 22.6 km and 74 supports;
  • continuation of construction works for the 150 kV “Rome North-San Basilio” line, relative to the new section starting at the Rome North Electrical Station for a length of 4 km with green coloured pylons and tubular supports, consistently with the requirements of the Rome Nature Body.

The complete rearrangement of the grid, as envisaged in the Plan, will generate significant environmental benefits related to the energy savings expected, amounting to about 58,000,000 kWh, equivalent to the annual consumption of about 20,000 households.

The management of the electricity distribution network of Rome and Formello is characterized by the continuous improvement of the performances, with particular attention to energy efficiency.

Every year Areti implements initiatives to reduce grid losses, which include the reclassification of medium voltage levels from 8.4 kV to 20 kV and the installation of MV/LV transformers with very low losses. For further information see the Energy savings section in the chapter The use of materials, energy and water.

The activities performed for the smart city that continue to improve the performance of the networks thanks to the evolution and integration of management systems and, in general, the applications of technological innovation in the management of the network, are illustrated in the chapter Institutions and the Company.

Also as a result of the activities mentioned above, energy losses on the grid during the year amounted to approximately 7% of the total transported, a slight decrease compared to 2018.

108 With regard to polychlorinated biphenyls (PCBs), pursuant to Legislative Decree no. 209/99 and Law no. 62/05, Acea disposed of transformers with PCBs above the 500 ppm threshold in 2009. In 2019, 194 transformers with PCBs above 50 ppm but below the 500 ppm threshold, including 93 for public lighting, were reported to Arpa, and 10 transformers were disposed of, for a total weight of 13,420 kg and a quantity of PCBs of 1,838 ppm.
109 According to the following legislative references: Legislative Decree no. 81/08; Italian Electro-technical Committee Guide 211-6 first ed. of 01/2001; Prime Ministerial Decree 8/7/2003 “Fixing of the limits of exposure, the values of attention and the quality objectives for the protection of the population from electric and magnetic fields at the network frequency (50Hz) generated by the power lines”.