Energy saving

During 2018 Ecogena maintained its certification as an ESCo (Società di Servizi Energetici - Energy Services Company), in accordance with UNI CEI 11352. It is therefore 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).
The activities assigned to Ecogena include also the design and building of trigeneration plants1 for the production, in combined mode, of electrical, heat and cooling energy. In 2018 cogeneration plants were managed, combined with district heating networks for a total of 6.6 MW of electrical power2. Total energy production is in line with the previous year.

As at 31.12.2018, the plants managed by Ecogena had been awarded 6,683 TEEs under the Ministerial Decree of 5 September 2011, of which 1,359 related to 2017 production (and finalised in 2018) (see Table no. 61).
In order to achieve the aim of energy saving, as regards Areti, actions concentrated on acquiring EETs on the market governed by the electricity market authority (EMA), as well as purchasing 1,359 certificates from Ecogena. The residual obligation for 2018 was 89,078 TEEs, compared with the initial 111,348 TEEs, to which should be added the residual portion of the 2017 obligation, equal to 44,512 TEEs, and the residual portion for 2016, equal to 35,610 TEEs. In November 2018, part of the remainder of 2016, equal to 15,344 TEE, was cancelled.


   of which plants owned by Ecogena65.0
   of which plants owned by third parties1.4
Thermal energy87.6
   of which plants owned by Ecogena72.1
   of which plants owned by third parties15.4
Refrigeration energy (all owned plants)15.6
TOTAL TEEs (all from plants owned by Ecogena)1,2031,0391,359

(*) Estimated 2018 data, due to unavailability of November and December. Figures for the previous two years have been adjusted due to improved reporting.

Energy efficiency actions

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

With regard to the headquarters in Piazzale Ostiense and following the energy efficiency works in 2017, in 2018 the Energy Performance Service was launched, i.e. the measurement and periodic reporting of the consumption recorded on the power lines being reconfigured in the same location. As at 31.12.2018 the intervention produced energy savings of 109 MWh.

For the Water industrial segment – considering the companies in the perimeter: Acea Ato 2, Acea Ato 5 and Gesesa – this year there was a decrease in consumption (-5% compared to 2017), mainly due to less dry weather conditions, which allowed less use of emergency systems that are very energy-intensive. In addition, where possible the companies have improved their specific energy efficiency.

In terms of energy efficiency, in 2018 Acea Ato 2 achieved energy savings of about 18.7 TJ/year, with savings of about 1,870 tonnes of CO2 emissions. More specifically, significant projects focused on the one hand on the recovery of water losses, which led to an efficiency gain of 11.5 TJ, and on the other hand on treatment, where projects to optimise the oxidation sector of the treatment plants (Capoluogo, Cerquette, Cobis and Ostia) led to an energy efficiency gain of 6.8 TJ. The replacement of lighting fixtures with LED systems at the company’s plants continued in 2018, with savings of about 0.14 TJ.

Acea Ato 5 saw a decrease in consumption (about 7%) mainly due to better climatic conditions, but also to some interventions aimed at increasing energy efficiency, both at two purifiers (Madonna del Piano and Castro dei Volsci) and at water pumps and well fields, thanks to the installation of suitable instrumentation – inverters, level probes and interconnections – which produced an efficiency of about 3.5 TJ.

Gesesa’s consumption increased in absolute terms, but this is due to the acquisition of a municipality (Morcone) and the commissioning of five new sewerage pumps and the same number of treatment plants. Compared to 2017, savings of about 1 GWh was achieved with the same number of electrical user accounts due to an optimisation of the distribution of the flow rates of the Sorienza spring and a reduction in network pressures.

For the Energy Infrastructure segment, the company Areti, which manages electrical energy distribution, continued the efficiency raising schemes set up following the energy diagnoses performed at some company locations, as part of the UNI EN ISO 50001 energy management system and according to Legislative Decree no. 102/2014.

In particular, in 2018 the transformation of the air conditioning and domestic hot water production system into heat pumps at the San Leone site in Via Grotte d’Arcaccio, Rome was completed.

Particularly important are the works on the distribution network aimed at energy saving. This involves, in particular, optimisation of the set-up of the MV network and gradual transformation of the voltage level from 8.4 to 20 kV and other adjustments for the HV and LV lines and the use of 268 MV/LV transformers with very low losses. Table no. 62 shows the type of work and the relative energy savings of the last three years. These efficiencies have led in 2018 to overall energy savings of about 15.8 TJ and about 1,600 tonnes of CO2 avoided.

There was also a reduction in the energy consumption of public lighting systems: between 2016 and 2018, the total number of lamps fell from 220,474 to 225,619. On the other hand, consumption for public lighting fell from 167.9 GWh (604 TJ) in 2016 to about 84 GWh (302 TJ) in 2018, being halved mainly due to the installation of LED technology lamps: from 84,871 in 2016 to 191,200 in 2018.

Finally, in the Environment segment, in 2018 a number of energy efficiency initiatives were launched for lines 2 and 3 of the San Vittore plant. The initiatives consisted in replacing the “overheating benches” of lines 2 and 3, which improved the thermal exchange of combustion fumes in the boiler with water, and in creating a new “setting” for the DeNOx3 plant of line 3, with the reprogramming of the quantities of methane (and ammonia solution) necessary to reduce nitrogen oxides, both with positive repercussions on consumption.

Table no. 62 – ENERGY EFFICIENCY IN ARETI (2016-2018)

reduction in losses on the network29,36524,95914,627 (*)
reduction in losses through the purchase of new transformers4746621,112
Transformation of air conditioning and domestic hot water production system into heat pumps--47
thermal power plant revamping616161
renovation of inside lighting system in one of the locations555
renovation of outside lighting system at CP Casaletto-5454

(*) Value estimated while awaiting the network analytical study.

(1) Cogeneration, i.e. the combined production of electrical and thermal energy, allows high efficiencies to be achieved, between 80 and 90%. Trigeneration, which is a special application of cogeneration, allows use of a part of the thermal energy recovered in order to produce cooling energy in the form of cooled water for air conditioning in rooms or for industrial processes.
(2) The 6.6 MW includes 1 MW relating to management of the Prepo power plant, in the municipality of Perugia, not owned by Ecogena.
(3) The DeNOX system is the system for the reduction of nitrogen oxides (NOx) that uses a conversion reaction with ammonia, generating nitrogen.