Energy savings

[GRI - 201-2], [GRI - 302-3], [GRI - 302-4], [GRI - 302-5], [GRI - 305-5],

Ecogena is the organisation registered to develop energy-efficiency initiatives for the Group Companies and report their results to the Gestore dei Servizi Energetici (GSE) for the awarding of Energy Efficiency Certificates (EECs). From their activation to 31 December 2023, the cogeneration plants managed by Ecogena received a total of 9,661 EECs under the Ministerial Decree of 5 September 2011, of which 531 were in 2023. Furthermore, the energy efficiency initiatives implemented by the Acea Group, reported by Ecogena and validated by the GSE, received a total of 26,438 EECs, of which 7,424 in 2023.

Areti, in its capacity as a distribution company, is required to reach a quantitative annual primary energy saving target defined by the authorities in terms of EECs. In this regard, in 2023 the Company cancelled 38,668 EECs, of which 16,729 were related to the 2022 quota and the remaining 21,939 to the previous quota.


Every year, Acea implements measures to improve energy efficiency, aimed specifically at Companies operating in the Water and Environment Business and Areti.
In 2023, considering the photovoltaic systems at the plants of Acea Ato 2, AdF, Deco, Orvieto Ambiente and Terni, total energy consumption (on-site self-consumption) was 2,670 MWh, with a consequent approximately 840 tonnes of CO2 emissions avoided. In the water sector, the Company implemented the following energy efficiency measures in 2023:

Acea Ato 2 achieved a total saving of 35.1 TJ (9.8 GWh). The most significant eciency gains, amounting to 31.3 TJ (8.7 GWh), concerned two water centres, while for the water treatment sector, specific optimisation work was carried out at two treatment plants, with a resulting efficiency gain of approximately 3.5 TJ (0.96 GWh). Additionally, further savings related to reduced water losses. For Acea Ato 5 increases in efficiency, corresponding to 3.7 TJ (1.0 GWh), are mainly attributable to replacing the pumps used for withdrawal at springs and well fields, installing inverters, and increasing the efficiency of the treatment system.

Gori implemented measures to increase efficiency for total savings of 61.7 TJ (17.1 GWh), primarily through the use of more energy efficient water sources, the use of higher-efficiency electric pumps, and increasing the efficiency of certain processes at treatment plants. Specifically, the reduction in sourcing from underground water, and consequent less use of certain lifting devices that are more costly from an energy perspective, resulted in a consistent reduction in electricity consumption234.
AdF achieved efficiencies for approximately 10.2 TJ (2.8 GWh) by increasing efficiencies at the collection plant, district planning, management of pressure levels and leak detection and the energy optimisation of a treatment plant. Gesesa has achieved a savings by improving the efficiency of 0.5 TJ (0.2 GWh) resulting from actions to manage pressure in the context of the current district planning process.

Overall, thanks to the measures referred to above, the Water Business avoided over 9,700 t di CO2.
In the Environment Business, actions to improve energy efficiency in 2023 included the works at the San Vittore del Lazio plant to optimise combustion on three lines which led to annual efficiency gains of approximately 19 TJ (5,300 MWh of electricity). At the composting sites in Aprilia, Monterotondo and the compost line at the Orvieto Ambiente plant, additional energy efficiencies were introduced to optimise processes based on the use of an inverter and other specific management improvements, which resulted in savings of 0.8 TJ (213 MWh). In total, CO2 avoided at sites in the Environment segment, including the two waste-to-energy plants, amounted to approximately 1,700 t.

In the Energy Infrastructure segment, Areti continued with energy eciency measures on the managed electricity distribution networks in 2023, specifically by replacing 105 MV/LV traditional transformers with the same number of ultra-low loss transformers, reducing electricity consumption by 136 MWh, and working on the HV/MV/LV distribution network to optimise the MV network structure and upgrade the HV and LV lines, for a total of 514 MWh of savings, as estimated to date (including the use of transformers). In total, in 2023, there was an energy saving of approximately 1.9 TJ (0.5 Gwh), thus avoiding 162 tonnes of CO2235.

Consumption for public lighting in 2023 was slightly down at 237 TJ (66 Gwh) (-2.4% compared to 2022). The ratio of LED lamps to total lamps was 92%.
In 2023, Areti’s operating personnel used a total of 87 electric vehicles (35 via car sharing, and 52 vehicles assigned individually to operating personnel and work teams). According to monitoring by Areti, total journeys amounted to approximately 207,570 km, consumption was around 33 MWh and a net saving of approximately 21,060 kg of CO2 was achieved thanks to the avoidance of diesel-powered vehicles.

234 The overall reduction recorded in 2023 compared to 2022, on the same scope, was approximately 9,500 MWh, the equivalent of a 4.4% total reduction in overall consumption recorded in 2022.
235 Calculations for estimation of CO2 emissions avoided in the entire section Relations with the environment have been carried out using the 2021 Terna location-based conversion factor, equal to 0.315 tonnes of CO2/MWh. In the Sustainability Plan reporting, the same estimate is made using the 2019 conversion factor, in line with the calculation for definition of the 2024 target.