Other emissions of CO2


In addition to the emissions caused by electricity consumption, there are indirect emissions connected with the following aspects of Terna’s business:

  • air travel by employees;
  • grid losses.

indirect emissions of CO2 because air travels by employees

 CO2 emissions (tons)  
 2009  2008  2009  2008 
Domestic 3,511,970  3,793,592  1,013.1  1,090.0 
International 1,223,462  1,306,497  259,9  268,5 
Intercontinental   1,618,459  1,152,414  305,6  230,9 
 6,353,891  6,252,503  1,578.5  1,589.4 
Grid lossesare defined as the difference between the energy injected by producers and end consumption. Among Terna’s significant losses are those connected with the transmission grid. With its acquisition of approximately 18,500 kilometres of high-voltage lines from Enel, the losses on these lines are also taken into account. Both figures are the result of estimates, which break down the total losses of the system (including the distribution networks) in proportion to the voltage levels, beginning with calculations assuming particular grid configurations and also including the losses on the lines that are due to corona discharge (proportionate to the voltage) and the joule effect (proportionate to the current), as well as losses on the transformers.

Grid lossses (1)

  % of energy demand  (GWh)  Tons CO2-equivalent
 VHV grid (2)   1.23   3,897   1,657,013  
HV grid  1.39   4,404   1,872,559  

(1) Calculated using the “2009 provisional operating data of the national electric system”.
(2) In 2008 and 2007, the losses on the VHV grids amounted to1.32% .

It should be noted that Terna can only contribute to the amount of the losses, which are not completely under its control.

To understand this point, it is useful to distinguish between dispatching and grid development.

Dispatchingi transactions are necessary to ensure the constant balance between injections and withdrawals and avoid problems regarding grid security and dysfunctions. Such transactions take place according to regulated criteria and as part of the production structure determined by the energy market, and thus cannot be conditioned by Terna with the objective of minimising losses. It should be noted, however, that the energy market implicitly favours the more efficient producers and thus entails a trend of emission reduction greatly exceeding that of grid losses.

The production structure being equal, grid development would lead to greater efficiency and thus a reduction of losses. However, grid development allows the establishment of a production structure that was previously not possible and thus also allows consumption to increase. Furthermore, grid development itself is partly dictated by the need to connect new plants, whose location is not decided by Terna. Therefore, the overall effect of grid development on losses is not under the TSO’s control and cannot be determined in advance. Other factors can more than offset the increase in efficiency deriving from development of the grid, in terms of both the absolute amount of losses and the incidence of losses with respect to the total energy consumed.