Waste-to-energy plant

Acea’s Environment Business Sector also manages the waste-to-energy process and is nowadays a reference operator in central Italy with two plants - located respectively in San Vittore del Lazio and Terni. - that generate energy from waste.

In 2021, the energy produced by Acea through waste-to-energy reached 698 GWh.

Waste-to-energy is the process through which electricity is generated from waste combustion. How does the process take place? This is a summary of the main steps.

  1. Waste entering the plant is conveyed into the combustion furnaces.

  2. Combustion takes place with a water- and air-cooled mobile grille.

  3. The heat generated by combustion is recovered for steam production.

  4. The steam expands to activate a turbine that produces electricity to be injected into the grid.


A process that aims to be increasingly efficient, also in environmental terms by reducing the impact of the activity.
During the combustion process, for example, the fumes produced are treated on several occasions in order to minimise the pollutant emissions. The share of green energy produced in the two Acea plants is approximately 69%.


Finally, in addition to energy production, the waste-to-energy plants can significantly reduce the volume of waste disposed of in a landfill.

In 2021, waste-to-energy in Acea Ambiente plants generated 92,800 t of waste (78,733.16 t in the UL3 plant) + (11,766 in the UL1 plant) compared with 407,100 t of waste processed through waste-to-energy, with a ratio of 23% between outgoing and incoming waste. 


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