Discover the Acea Group online 2019 Sustainability Report

Energy saving

As noted, Ecogena is the appropriate body to develop the energy efficiency initiatives of the Group Companies and report their results to the Gestore dei Servizi Energetici (GSE) for the awarding of Energy Efficiency Certificates (TEE).

As at 31.12.2019, the plants managed by Ecogena received 7,591 TEEs under the Ministerial Decree of 5 September 2011, of which 954 related to 2018 production (and finalized in 2019) (see table no. 48).

To make it possible for Areti to achieve its energy savings goal, the actions of the year were focused on the purchase of EECs on the market managed by the electricity market operator (EMA) equal to 122,369 EECs, to which is added the residual portion of the 2018 obligation equal to 89,073 EECs with respect to the initial 111,348 EECs, and the residual portion relating to the 2017 obligation equal to 14,132 EECs.


Acea, during the year in question, carried out various schemes for the recovery of energy efficiency in the managed processes, in particular in the Companies engaged in the Water, Energy Infrastructure and Environment segments.

In 2019, for the Water industrial segment, despite the numerous efficiency initiatives described below, there was an increase in electricity consumption equal to 13% compared to 2018, mainly due to the new acquisitions of plants by Gori129 and the launch of other infrastructure by Acea Ato 2, including: the Grottarossa drinking water plant130, the new departments in the Roma Nord treatment plant (such as anaerobic digestion and thermal drying of sludge) and the ozonolysis of sludge at the Ostia treatment plant. The energy efficiency measures carried out by the Companies on ordinary activities partly offset the overall increase in consumption.

In this regard, Acea Ato 2 achieved a total savings of 9.3 TJ (2.59 GWh) in 2019, against an expected annual energy savings target of 4.7 TJ (1.3 GWh). More specifically, with regard to the water sector, through significant interventions aimed at the recovery of the resource, about 2 TJ (0.56 GWh) of electricity was saved thanks to efficiency works on five valves of a pumping group of the Ceraso plant, while with regard to the purification sector there was an energy efficiency of about 3.4 TJ (0.93 GWh) through interventions to optimize the oxidation sector of the Fregene, Palmarola and other minor plants (purification plants of: Reotula, Montelungo, Vignacce, Grottoni and Santa Severa). Regarding the efficiency improvements related to the consumption of electricity avoided for water loss recovery, a value of 3.9 TJ (1.09 GWh) was quantified, referring to the area of Rome.

In Acea Ato 5 the efficiency improvements equal to about 2.4 TJ (0.68 GWh) were related to the installation of pressure meters, inverters and level probes.

Gori carried out efficiency projects mainly related to the division of the water network into districts and the installation of inverters, for a total of 2 TJ (0.6 GWh) saved.

Gesesa’s consumption, in absolute value, decreased by about 3.6 TJ (1 GWh) compared to 2018. Moreover, increased efficiency and revamping initiatives are under way for the plants, with the installation of more energy-efficient equipment also from an energy point of view.

In the Energy Infrastructure segment, during the year Areti continued several efficiency improvement projects on the managed electricity distribution grid:

  • the use of 344 MV/LV transformers with very low losses, which allowed a reduction in electricity consumption of 404 MWh; 
  • other interventions on the HV/MV/LV distribution network aimed at optimising the structure of the MV network and other adjustments for the HV and LV lines, for 946 MWh saved.

Table no. 60 shows the type of work and the related energy savings of Areti for the last three years. These efficiencies have led in 2019 to overall energy savings of about 5 TJ (1.4 GWh) and about 500 tonnes of CO2 avoided.


reduction in losses from the grid24,95925,200 (*)4,860 (**)
of which reduction in losses through the purchase of new transformers6621,1121,454
transformation of air conditioning and domestic hot water production system into heat pumps-4794

(*) Value measured after a detailed study of the grid.
(**) Value estimated while awaiting the detailed study of the grid.

In 2019 consumption for public lighting fell to about 70 GWh (252 TJ) (115.6 GWh and 416.2 TJ in 2018), mainly due to the installation of LED technology lamps: from 172,971 in 2017 to 205,670 in 2019, out of a total of 225,730 lamps.

A further positive contribution was provided by the 25 electric vehicles in use and shared by the Company’s staff.

Areti monitors the average and maximum travel of vehicles on a daily basis, the specific consumption in km/kWh, the battery use and the amount of CO2 not emitted. The monitoring activity has found: a total of about 65,000 km of travel corresponding to electricity consumption of about 10,000 kWh and savings of about 6,200 kg of CO2, net of emissions from the energy consumed.



Finally, in the Environment segment, in 2019 some energy efficiency improvements continued at the San Vittore del Lazio plant, which were launched in 2018. In particular, in 2019 the project consisted in creating a new “configuration” for the DeNOx plant131 of line 3, with the reprogramming of the quantities of natural gas (and ammonia solution) necessary to reduce nitrogen oxides, both with positive repercussions on consumption132.

129 Since February 2019 Gori has acquired the management of: a well field in Angri, regional plants in the Sarnese area including the large plants of Santa Maria La Foce and Santa Marina di Lavorate (Sarno); regional plants in the Monti Lattari and Sorrento Peninsula area including the Sepolcri Water Plant (Gragnano). Also acquired during the year were the purification plant in Bosco Fangone (Nola) and the related supply lifts and the purification plant in Nocera (Nocera).
130 In addition to the start of the new Grottarossa drinking water plant, the Cecchina Bis plant was used on an ordinary basis. Until 2018 it was used occasionally as a reserve, then from the end of 2018 on an ordinary basis to no longer use the previous reserve of Lake Bracciano.
131 The DeNOx system is the system for the reduction of nitrogen oxides (NOx) that uses a conversion reaction with ammonia, generating nitrogen.
132 In 2019, the savings of methane thanks to these interventions were more than 700,000 Sm3.