Atmospheric emissions

Atmospheric emissions from production activities are monitored in a planned and constant manner. The plants are managed according to UNI EN ISO 14001 and UNI EN ISO 45001 standards. Acea Ambiente also applies the UNI EN ISO 50001 management system, while the waste-to-energy plants, the Orvieto plant and the Deco sites are also registered under the European EMAS III scheme, extended until 2024²⁰⁹.
The most relevant macro-pollutants, which are attributable to the Acea Ambiente and Acea Produzione plants, are monitored through Continuous Emission Monitoring Systems (CEMs). In 2022, macro-pollutants were recorded at very low values and are decreasing compared to previous years (see Table no. 66).

Table no. 66 – Total atmospheric emissions of pollutants from the main Group plants (2020-2022)

NOTE: the emissions refer to the plants of Acea Ambiente – waste-to-energy and Acea Produzione.

Specifically, monitoring of the waste-to-energy plants is carried out by means of fixed and mobile stations that sample and analyse the fumes coming out of the chimneys, measuring concentrations for numerous parameters that are periodically checked by internal personnel and certified by qualified external laboratories. Again in 2022, the values of the main pollutants were also significantly below the legal limits (see Table no. 67).
At the San Vittore del Lazio plant, the monitoring campaigns carried out for PM10, PM2.5²¹⁰, heavy metals (fixed and mobile survey stations) and PAHs (polycyclic aromatic hydrocarbons), dioxins and furans (mobile only) did not detect any critical values. Other actions in the year including the monitoring of diuse and fugitive emissions and the continuation of a biomonitoring campaign using bees as bioindicator insects (see Safeguarding of Land and Biodiversity, in the chapter Environmental Sustainability and the Main Challenges). Finally, each waste-to-energy line has systems to monitor emissions from the chimney, enabling continuous tracking for concentrations of pollutants 24/7, with availability of data on the Group website (www.gruppoacea.it).
Environmental monitoring is carried out at all plants. For example, at the Aprilia plant, a monitoring campaign was conducted in December 2022 to survey the presence of hydrogen sulphide, volatile organic compounds, nitrogen oxide, methane odours, and other components.

Table no. 67 – Concentrations of atmospheric emissions generated by waste-to-energy plants (2020-2022)

(*) The analysis of PAH, dioxins and furans and heavy metals and their composites are four-monthly and discontinuous. The “<” symbol identifies the concentration values that are equal to or below the thresholds that the devices used by the laboratory are capable of measuring.
(**) Reference parameters, Legislative Decree no. 46/2014, 2000/76/EC and IEA, are separate for each waste-to-energy plant.
NOTE: for San Vittore del Lazio, over the years the recorded concentrations of the parameters HCl, SO2, dust and HF were close to the instrument’s detection limit. Therefore, in these measurement areas deviations are to be considered insignificant for absolute changes in concentrations and masses.

Monitoring carried out on installations at risk²¹¹ has shown the absence of emissions in significant quantities of substances responsible for reducing the ozone layer (for consumption see the section Resources used, in the Environmental accounts).

GREENHOUSE"GAS EMISSIONS

Acea quantifies its CO₂ emissions by monitoring and evaluating the carbon footprint of the individual macro production processes according to the guidelines of the GHG protocol²¹² which requires reporting in the categories of direct (Scope 1) and indirect (Scope 2 and Scope 3).
Direct Scope 1 emissions mainly come from the Group’s two waste-to-energy plants and the thermoelectric power stations. As of 2022, two plants are subject to the Emission Trading Scheme (ETS), specifically the Montemartini and Tor di Valle power stations. As of March 2022 and with retroactive²¹³ effiect, the Terni waste-to-energy plant is no longer included in the scope of application of the ETS Directive.
The allowances assigned under the NAP (National Allocation Plan) are lower every year and in any case small, compared to the actual emissions recorded. Data for the three-year period 2020-2022 is presented Table no. 68.

Table no. 68 – CO2 emission allowances as per the National Allocation Plan (NAP) and actual emissions by plant (2020-2022)

(*) As with previous years, in 2022 the applicable legislative framework allowed the Tor di Valle plant to benefit from free of charge emission allowances (3,472 t) as it serves a district-heating network.
(**) The 2021 figures for actual emissions have been updated with the certified figures.
(***) Estimated emissions, pending certification by the responsible body.

Scope 1 emissions include other components deriving from certain processes of plants in the Environment Segment (composting, treatment and disposal of liquid waste), from drying at treatment plants, from petrol and diesel vehicles in the fleet, from leaks of sulphur hexafluoride (SF₆) that may arise at Areti plants, from combustion processes for heating of premises and offices, and finally from leaks of freon gases from air-conditioning units.
The amount of CO₂ emitted by the waste-to-energy plants in 2022 increased slightly compared to 2021 (see Table no. 69). This was mainly due to less biodegradable waste entering and processed for waste-to-energy at the Terni plant (renewable energy fell from 43.4% to around 41%).
The increase in CO₂ emissions from Acea Produzione's thermoelectric power stations is attributable to a higher production of thermo- electric energy and consequent increase in fuel use, while the higher emissions related to the integrated water service processes are mainly due to occasional work by Acea Ato 2 at a specific water centre.

Scope 2 greenhouse gas emissions from electricity consumption in 2022 were in line with 2021 (+1%). Efficiency gains in the water sector, for example, oset the increased consumption caused by the use of pumps as a result of low rainfall. For more details see the paragraph on Energy Saving. Emissions from electricity grid losses increased (by about 4%) due to the increase in electricity demand on the distribution grid (+2%).

Scope 3 emissions include those deriving from the gas and electricity sales, electricity consumption by suppliers of purchased goods, services and works, business travel and, from 2022, main subsidiaries²¹⁴ (scope 3 category “investments”) (see Table no. 69).
Emissions from business travel rose in 2022 due to the end of restrictions caused by the pandemic and the resumption of normal business travel.
Scope 3 emissions associated with the purchase of goods, services and labour are calculated using monitoring data for energy consumption outside the Group, requested from a representative panel of suppliers using a questionnaire (see the section Energy consumption outside the Group). In particular, the data requested regards energy (primarily consumption of fuels, electricity and vehicle fuels) and data for refrigerant gases used at supplier premises, which contribute to this category of Scope 3.
To reduce emissions from electricity sales (calculated in the table using both the location-based and market-based methods), Acea Energia offers customers GO-certified green electricity commercial rates. Since 2021, all new retail customers on the free market are offered exclusively GO-certified green energy, with the gradual roll-out to contracts signed before this date. The “sustainable” rate also covers gas thanks to osetting through the purchase of VER (Verified Emission Reduction) certified carbon credits. For more details, see the section on Customer Care in the Customers chapter. Green energy sold by Acea Energia to free market customers in 2022 totalled 2,536 GWh (2,196 GWh in 2021), corresponding to 42% of total energy sold to free market customers (see also the Environmental Accounts). The sale of electricity with GO certification has therefore led to a saving of approximately 799,000 t of CO₂ in the Scope 3 category. For gas sales in 2022, offsetting measures are expected to cover approximately 54 MSm³ (estimated figure; 3.3 MSm³ in 2021 according to the updated figure), corresponding to approximately 107,000 t of CO₂.

INTENSITY INDICES FOR GREENHOUSE GAS EMISSIONS

Scope 2 carbon dioxide emissions, deriving from leaks on electricity distribution networks, relative to total electricity distributed, is one of the intensity indices for greenhouse gas emissions monitored. The index is in line with 2021, rising from 0.0099 t/MWh (updated figure after consolidation) to 0.0101²¹⁵. However, performance of the Scope 1 emissions index on energy produced²¹⁶ fell. The indicator stands at 462.1 g/kWh (413.8 g/kWh considering also the photovoltaic production of the subsidiary not consolidated on a line-by-line basis), with an increase due mainly to the reduction in electricity production from hydroelectric (-23% compared to 2021 production) and waste-to-energy (-5%) sources. Finally, the emissions intensity index linked to value added improved, decreasing by 4% compared to 2021. Total Scope 1 plus Scope 2 emissions remained almost stable (+0.8%), while value added increased by 5% (see Table no. 69).

Table no. 69 – Environmental indicators: CO₂ emissions, intensity indices for greenhouse gas emissions (2020-2022)

(*) The 2021 figures for the Tor di Valle and Terni plants have been adjusted after the ETS certification, while the 2022 figure is estimated pending certification by a third-party body for Tor di Valle and the definitive analyses for Terni.
(**) The figure includes the emissions of the ancillary services of the waste-to-energy plants, not strictly related to the production of electricity, of Acque Industriali, Aquaser, Berg and Demap.
(***) Data refers to uses of dryers and generators. The increase in 2022 was mainly due to occasional works by Acea Ato 2 at a water centre in Albano Laziale.
(****) These are the tonnes of equivalent CO₂ corresponding to the emissions of insulating SF6 present in Areti’s HV equipment (1 t of SF6 equates to 23,500 t of CO₂, GHG Protocol-5th Assessment Report- AR5).
(*****) In the last three years, the replenishment of HCFC fluids in the Group’s plants was so small that it did not lead to significant CO2 emissions.
(******) The indirect emissions (Scope 2) include all the Companies within the NFS scope. As an emission factor per unit of electricity consumed (t CO₂/MWh), for the location-based calculation the value of 0.315 was used for 2021 and 2022 (0.336 for 2020), as per Terna’s “International Comparisons” document. For the calculation of Scope 2 emissions using the market-based method, the residual mix coeffcients are the following for 2020, 2021 and 2022, respectively: 0.466 t/MWhe, 0.459 and 0.457 (Source: AIB document “European Residual Mixes 2021”). Emissions due to technical network losses in 2021 were calculated on the basis of the corresponding adjusted figure in 2022.
(*******) As of 2022 emissions from commuting are not calculated as the values are negligible.
(********) This value, estimated, refers to suppliers of goods, services and works. The 2022 figure is broken down as follows: 21,871 tonnes of CO₂ for suppliers of services and works and 4,803 tonnes of CO₂ for suppliers of goods.
(*********) Data for the 2020-2021 two-year period have been recalculated, excluding from the numerator the emissions of the investee companies Acque, Publiacqua and Umbra Acque. From 2022, these are reported as Scope 3 emissions under the Investments category.
(**********) Scope 1 emissions included are those from power generation plants, including Ecogena. If the photovoltaic production of the investee company not consolidated on a line-by-basis were also taken into account, the indicator for the year would be 413.8 g/kWh. In any case, the indicator rose in 2022 mainly due to the increased CO₂ emissions from waste-to-energy processes (due to plant downtime), while energy production fell.
NOTE Emission factors for Scope 1 emissions are taken from the standard parameters – ISPRA data 2021, DEFRA 2022 and GHG Protocol-5th Assessment Report-AR5.

209 In the case of Deco, the EMAS registration is valid from 2022 to 2025.
210 PM10 refers to particles with a diameter less than or equal to 10 (m. The term PM2.5 refers to particles with a diameter less than or equal to 2.5 μm.
211 This is primarily air conditioning equipment using refrigerant gases subject to the 1987 Montreal protocol, particularly chlorofluorocarbons.
212 See www.ghgprotocol.org for more information.
213 In March 2022, following an exemption request submitted to the MISE, with Resolution 66/22 the National Committee for the management of Directive 2003/87/EC and for support in the management of project activities of the Kyoto Protocol, determined, with retroactive eect, the exclusion of the Terni plant as of 31 December 2020.
214 Acque, Publiacqua and Umbra Acque.
215 The figure is estimated.
216 The index is calculated using emissions from production (Acea Produzione's thermoelectric power stations, Ecogena plants, waste-to-energy plants) as numerator and total energy produced by the Group's plants as denominator.