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The countless implications of water as a resource for A2A


Water as a resource plays a key role in a large number of the Group’s activities.

ActivityUse of water
Hydroelectric productionWater represents a source of energy. The hydrographic basins significantly involved are those of the rivers Adda and Spoel in the Upper Valtellina in Lombardy, and the rivers Neto, Simeri, Ancinale and Savuto in Calabria. The water extracted is returned in full.
Thermoelectric productionWater is necessary for the production of steam, for cooling the thermodynamic cycle and for limiting the dispersion of dust. The water bodies involved in withdrawal are: the Valentinis canal (Monfalcone thermoelectric power station - Gorizia), the Muzza canal (Cassano d’Adda thermoelectric power station - Milan) and the River Mincio (Ponti sul Mincio thermoelectric power station - Mantua). The water taken for cooling is returned in full to the same water body and with the same qualitative features except for a slight increase in temperature.
District heatingWater usage is mainly due to the topping up of network water, which is generally carried out with drinking water or aqueduct water or water recovered from emptying out the network and the boilers of the production plants. In some of the A2A Group’s plants underground water heat pumps are used to produce energy, with the water taken from wells located close to the plant.
Electricity distributionIn certain plants water is needed to cool the transformers and this comes partly from wells and partly from aqueducts.
Environment sector

Water is necessary for urban hygiene services, for waste treatment, for limiting the dispersion of dust and in waste to energy plants, as well as energy production uses and cooling down residues. The water comes from wells or aqueducts. Water reuse systems have been built to limit usage, for example:

  • the process waste interchange system between the Brescia waste to energy plant and the Lamarmora power station, which enables the rainwater and process water at both of the plants to be used to extinguish the ashes at the bottom of the boiler of the waste to energy plant;

  • the Bergamo plant for the production of energy from Refuse Derived Fuel (RDF), where the cooling water comes from the nearby purifier. Here the water cycles in two directions: the water coming out of the settling tank of the purifier is used in the condenser of the waste to energy plant to complete the plant’s thermodynamic cycle and is then returned to the purifier, heated by a few degrees, enabling the kinetics of the biological purifying process to be accelerated;

  • the plants for washing swept dirt use water purified at the end of the cycle and recircled;

  • in some cases rainwater is collected for watering purposes.

Integrated water cycleWater is the primary resource taken for distribution to residents. The following paragraph goes into further detail about the management of the integrated water cycle.

Aqueduct water is a source of water that is particularly valuable because it comes from deep uncontaminated aquiferous layers that are downstream from a treatment process so as to make it drinkable. Built in years when the issue of water resources did not have the importance it has today, certain plants also use aqueduct water for purposes for which it is not necessary. A2A, though, has set up initiatives to reduce the use of this resource, replacing it where possible by industrial water pumped up from owned wells.

Control of water consumption for electricity distribution in Milan

Electricity distribution network equipment is generally air-cooled, thanks to the use of “ONAN” transformers; these are oil transformers with a natural circulation of oil and air. In the Milan network, certain equipment is however cooled by aqueduct water. Since A2A has as its objective to reduce the volume of water taken from the municipal water network, a study has been conducted to renovate the C.P. Gadio plant and make it more efficient, and a similar feasibility study will also be carried out for the Suzzani substation.

At the Monfalcone thermoelectric power station, the well-water procurement system has been controlled since 2011 by a working logic that optimises the withdrawal on the basis of the level of water stored and usage, eliminating the volume of water that was previously withdrawn and selected. A significant reduction has been obtained by this method in both the withdrawal and the volume of water discharged.