Waste to energy
Energy recovery from waste is a phase of the Circular Economy 110 that both Europe and Italy want to develop. In fact, in addition to providing energy and economic advantages, it allows a notable volumetric reduction and the biological
stabilisation of waste, avoiding as far as possible the disposal of this waste in landfill as such.
In addition to the activities already described of waste treatment and anaerobic digestion, Acea Ambiente also manages the waste- to-energy process through two plants, one in San Vittore del Lazio and the other in Terni. The plants operate according to certified environmental management systems. Indeed, between the end of 2017 and 2018 they obtained the renewal of their environmental certification (UNI EN ISO 14001:2015) and extended the EMAS III European registration to the whole of 2021.
For more on these aspects see also the section on Management systems in Corporate identity.
The Plant of San Vittore del Lazio is comprised by three independent lines of waste to energy designed to be fed with fuel waste- derived fuel (WDF), now called Secondary Solid Fuel (SSF), with these characteristics:
- 52 MWt of thermal power installed for line 1 and 56.7 MWt of thermal power installed for each of the other two lines;
- 13.9 MWt of electric power installed for line 1 and 15.1 MWt of each of the other two lines;
- Approximately 400,000 t/year of CSS, sludge and other waste at full capacity.
2018 was a year of normal operation. The plant’s actual available electric power was about 44 MW and about 307 GWh of electric power was produced. In 2018 energy from waste has been generated from about 357,200 tonnes of waste.
In its current configuration, the San Vittore del Lazio plant is the largest in the Lazio Region and plays an important role in the management of urban waste, both for the particularly advanced technologies used for its construction and for its considerable treatment potential.
TABLE NO. 51 - THE SAN VITTORE DEL LAZIO WASTE-TO-ENERGY PLANT: OPERATING DATA (2016-2018)
| u. m. | 2016 | 2017 | 2018 | |
| incinerated fuel | t | 281,917 | 345,639 | 357,174 |
| gross electric power produced | GWh | 243,68 | 301.15 | 306.731 |
| conversion efficiency (*) | kWh/kg CSS | 0.86 | 0.87 | 0.86 |
[110] The European Union's circular economy package has been in force since 04.07.2018.
The Terni plant is comprised of a waste to energy line and has the following characteristics:
- 52 MWt of thermal power installed;
- 13.6 MWe of electrical power installed;
- 120,000 t/year of pulper waste (paper mill waste resulting from the pulping of waste paper), as the maximum potential for incoming waste.
TABLE NO. 52 - TERNI WASTE-TO-ENERGY PLANT: OPERATING DATA (2016-2018)
| u. m. | 2016 | 2017 | 2018 | |
| pulp incinerated | t | 99,768 | 99,970 | 99,971 |
| gross energy produced | GWh | 83.07 | 83.10 | 82.41 |
| conversion efficiency (*) | kWh/kg pulper | 0.83 | 0.83 | 0.82 |
The plant of Terni is also equipped with a photovoltaic plant, which in 2018 has generated about 341 MWh of electricity, in part consumed on site (about two-thirds) and in part injected into the grid.
For data on the emissions of both waste to energy plants see the chapter Air emissions in addition to the data in the Environmental accounts.