Energy consumption


EN3The transmission of electricity requires the direct consumption of energy only for a few activities that support the service:

  • EN4fuel for the Company’s vehicles (used for line inspections, repairs, and other activities mainly connected with the maintenance of lines and stations);
  • gas oil for emergency generating sets, which are used only in cases where electricity – the normal energy source for equipment – is lacking, in order to ensure the control and restoration of the normal operation of the electricity system;
  • gas oil and methane for heating, particularly in offices.

The indirect consumption of energy is represented by the electricity used to run stations and operating systems (more than 86% of the total) and in offices and workshops.

The following tables show Terna’s direct and indirect consumption. The database for energy consumption is still being improved. In some cases (gas oil for heating) monitoring regards purchases, with the consequence that the changes from one year to another can reflect procurement cycles rather than reductions or increases in consumption; with respect to the indirect consumption of electricity (offices and stations), in 2011 the changeover from estimated data to data based on measurements began. The published value is the result of an estimate allowing to cover 100% of plants and offices, and is based on exact measurements from meter readings of 79% of the power stations.

A comparison between the consumption registered and the estimated data obtained by using the same calculating method of past years indicated an overestimation of consumption for previous years, which were, therefore, revised downwards consistent with the new measurements. (Values published for energy consumed and for the corresponding CO2 emissions differ, therefore, from those published in the previous two years).

In detail, in 2011:

  • consumption of fuel (gas and gas oil) has increased by 3% as a consequence of an increase in the grid perimeter and managed assets, resulting in company vehicles having to cover increased distances;
  • consumption of methane gas for heating has increased due to more severe climates in some areas. The increase in the consumption of methane in three years should be viewed in relation to the simultaneous reduction of heating gas consumption (representing 87% of the value shown on the table under the entry “Gas oil for generating sets and heating”).

An increase in the consumption of electricity was registered, due to an increase (+5%) in the number of stations in 2011.


Direct consumption      
Gasoline for vehicles (2) 7,504 7,113


Gas oil for vehicles (2) 75,731 74,588 72,528
Methane for heating 9,468 7,277 6,144
Gas oil for generating sets and heating 11,289 12,890 13,279
Total direct consumption 103,993 101,869 98,933
Indirect consumption      
Electricity for stations and offices (3) 627,480 591,840 555,120
Total direct and indirect consumption 731,473 693,709 654,053
(1) I dati dei consumi diretti in tonnellate e migliaia di m3 sono riportati in dettaglio nelle tavole degli indicatori. Per convertire i volumi di risorse primarie in gigajoule sono stati utilizzati i parametri indicati nei protocolli del GRI – Global Reporting Initiative – G3. (2) Vengono considerati solo i consumi delle auto operative e non dei mezzi manageriali. I dati 2011 sono frutto di misure puntuali per il primo semestre e di stima – basata sulle variazioni registrate tra il 2° semestre 2010 e 1° semestre 2011 – per il secondo semestre. (3) Nell’arco del 2011 è stata svolta un’attività di ricognizione e approfondimento sui consumi di energia elettrica per l’alimentazione di stazioni e uffici. Alla luce dei risultati di tale attività è stato possibile inserire in tabella un dato più puntuale non solo per il 2011 ma anche rispetto a quanto precedentemente pubblicato per il 2010-2009.

In 2011, Terna created an internal work group, coordinated by the energy manager, for the rational use of energy. Through the Initial Energy Analysis, the Group’s activities will allow for fine-tuning the energy consumption database and will be aimed at:

  • identifying different uses for energy, underscoring areas of criticality and the elements that primarily influence consumption;
  • forecasting expected consumption and comparing it with actual consumption;
  • including the evaluation of energy consumption into corporate processes;
  • implementing energy policies.