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  • Grid development and system emissions
  • Reducing emissions: Terna’s plans

The overall reduction in CO2 emissions could add up to approximately 11 million tonnes per year.

The effects can be grouped into three categories:

Reduction of grid losses

Grid losses depend, among other things, on the length of the section of the transmission grid over which the electricity has to travel. In the simplest possible terms, the further away the point of consumption (withdrawal from the NTG) is from the point of production (injection into the NTG), the greater the losses for the same amount of consumption. In addition, over an equal distance, the losses are greater on a lower voltage line. Development works that improve the grid bring the points of withdrawal and consumption closer together: if all else is equal, grid losses are consequently reduced. A similar result is achieved by upgrading a section of the grid, for example, when a 400 kV line replaces a 150 kV line along the same route. The entry into service of the main development works provided for in the 2019 Development Plan will lead to an estimated reduction in energy losses through the grid of approximately 800 GWh a year. If such a loss reduction were to equate to a decrease in production from fossil fuel sources, this would amount to a reduction in CO2 emissions of approximately 280,000 tonnes per year.

Improvement of the production mix and interconnection with other countries

One of the primary aims of developing the electricity transmission grid is to overcome transport limitations between "electricity zones". The existence of these limitations imposes certain restrictions on being able to use the most efficient generating units for production, namely those that are less polluting in terms of CO2 emissions, while at the same time, for grid security reasons, necessitating production by obsolete power plants. The initiatives provided for in the Development Plan, together with the expansion of interconnections with other countries, would enable a more efficient production mix, with a greater share of production from higher yielding plants. The same amount of final consumption would thus be achieved with less fuel: the benefits would add up to a reduction in CO2 emissions of up to 6,340,000 tonnes per year.

Increase in renewable energy production

The main contribution to the reduction in CO2 emissions derives from the increased integration of renewable energy plants. Production of energy from renewable sources has grown rapidly in potential in recent years. In particular, wind and photovoltaic generation plants have witnessed a considerable increase, especially in Italy's southern and island regions.
One of Terna's main tasks is to plan upgrades of the NTG in order to promote the production of electricity from renewable sources, seeking to overcome any grid and operational constraints that may affect the injection of such energy into the grid, which benefits from priority dispatching rights.
The development solutions planned in response to these critical issues include interventions to upgrade sections of the primary grid, which indirectly reduces the limits on production from non-programmable renewable sources (NPRS), and interventions designed to upgrade local sub-transmission grids into which the energy produced from NPRS is directly injected. In addition to these interventions, collection stations have been planned for NPRS on the primary 400 kV grid, which will limit the number of new 150 kV power lines to be built with respect to the number that would otherwise be required. Overall, the works envisaged in Terna's 2019 Development Plan will release power from renewable resources amounting to approximately 5,500 MW, thereby obtaining a reduction in CO2 emissions of approximately 4,427,000 tonnes a year.

The overall picture of all Terna's environmental data is available for download here.

In terms of emission reduction, Terna’s plans can be grouped into four different types:

Containment of direct emissions: SF6

In the four-year period 2009-2012, Terna implemented a campaign to install new, more leak-proof equipment, with an estimated reduction in the leakage rate regarding total equipment installed - after exceptional faults - of approximately 0.10% over the five years after the installation campaign. Based on this estimate, the leakage rate was expected to be around 0.60%, given that the average rate for the period 2007-2008 was 0.70%, after exceptional faults.
During the period in which the 0.60% target was applied (2012-2017), Terna managed to keep SF6 leakages below the pre-set target, thereby avoiding 88,741 tonnes of CO2 emissions.
Compared with the average of 0.70% recorded in the period 2007-2008, 165,770 tonnes of CO2 were saved, an amount comparable to Terna's total annual direct and indirect CO2 emissions.
In the light of the actual performance recorded until 2017, in the early months of 2018 the target was reformulated as follows: 0.47 for 2018 and 2019; 0.45 in subsequent years.
The target values should be qualified, bearing in mind the already substantial decrease recorded in the previous five-year period, and the higher average leakage rates of other leading European TSOs (0.7% in 2017, the latest available figure).
In the following three-year period 2020-2022 the target will be even more challenging (0.45%), thanks to the expected effect of the additional containment measures implemented in the first two years.
Routine and extraordinary maintenance has enabled the faults that caused the rise in 2017 to be dealt with, and led to an all-time low rate of 0.38% being registered in 2018. This figure is well below the average for the five-year period 2013-2017 (0.47%), enabling Terna to save 13,541 tonnes of CO2.

Company fleet

The Company's operational vehicles are used nationwide to carry out power line inspections and, in general, to visit infrastructure and construction sites.
Terna's vehicle fleet consists of four helicopters, purchased in 2015, for carrying out scheduled and random inspections of power lines, and a fleet of cars that is frequently renewed, of which 86% are equipped with Euro 6 and Euro 5 engines.

Quantities and emissions for motor vehicles(1)

Change 18-17
% change 18-17
Total motor vehicles no. 1,436  1,344 1,323 92 6.85 
Nitrogen oxide (NOx) emissions(2) kg 7,594  7,631 8,260 -37 -0.49 

(1) The table shows the vehicles in Terna’s fleet that, in the period in question, were refuelled on at least one occasion, based on claims for fuel expenses. Consumption data for fleet vehicles is shown in the following tables.
(2) The figure is calculated on the basis of the data provided by motor manufacturers and included in registration certificates, as well as on estimates of the mileage covered by the vehicles. The figure shown in the table for 2018 refers to 83.0% of the Company’s operating vehicles (85.3% in 2017 and 85.4% in 2016).

Energy Management System

In line with its energy efficiency objectives, since 2015 the Terna Group has been certified in accordance with the UNI CEI EN ISO 50001:2011 standard.
In 2017, sensors were installed at 80% of Terna's main sites to measure energy consumption in real time. The analysis, which was carried out using time bands and the entire calendar year, highlighted numerous peculiarities regarding electricity use and enabled the definition of long-term improvement targets for all the sites monitored in 2018.
In 2018, a pilot project regarding the online monitoring of the electricity consumed by transformer substations was also launched, and in 2019 a representative sample of 23 substations, broken down by type of activity, will be involved nationwide. More than 20 meters will be installed in each station to accurately monitor the electrical energy used and, after monitoring, energy audits will be carried out to define improvement targets.
In 2018, energy audits were carried out at construction sites, office buildings, substations and sites. In 2019, energy audits will be carried out on a sample of 23 stations and other sites to be identified (construction sites and offices). The results of the audits will be submitted to Enea to comply with Legislative Decree 102/2014.

Energy efficiency in substations and offices

At Terna, the development of energy efficiency programmes relating to the use of electricity in substations and offices is experimental, as the Company's electricity consumption falls within the category of "own transmission uses" which, according to the industry’s regulator, are not to be included in operating costs.
In offices, the main sources of energy consumption relate to lighting, air-conditioning, heating and the use of computers and printers. A number of Terna’s offices have either been refurbished or are newly built under a long-term programme, which aims to upgrade the energy efficiency class of buildings owned by the Group, thereby combining civil engineering works with improved energy performance. With specific reference to Terna's main offices, the aim is to upgrade 70% of the buildings, measured in terms of total volume, to qualify for the highest energy efficiency classes (A-B-C).
Initiatives launched in recent years to reduce energy consumption, of which the benefits are measurable, include:

Improving the efficiency of air conditioning systems In 2018, Terna implemented a project to improve the efficiency of air conditioning systems at the head office in Rome, involving replacement of two air conditioning units. This initiative will lead to a reduction of approximately 115 tonnes in annual CO2 emissions.
Improving the efficiency of lighting systems In 2018, Terna implemented projects to improve the efficiency of lighting systems in the Naples transmission operating area and at the Montalto and Rome West electricity substations, which will reduce annual CO2 emissions by approximately 56 tonnes.
Summary of previous years' initiatives Since 2014, energy efficiency initiatives have been launched, leading to a reduction of around 444 tonnes of CO2 at 31 December 2018 (equal to 174 tonnes of CO2 in 2018).
Forecast for initiatives in 2018 For 2019, six new energy efficiency initiatives have been planned with an estimated annual reduction of 120 tonnes of CO2.
Self-production of electricity from renewable sources In 2018, the plant for self-producing electricity from renewables for the Turin Botticelli office entered service, which resulted in a reduction of approximately 22 tonnes of CO2. In addition, a self-production plant has been operating at the Camin (PD) Infrastructure Unit since 2017, resulting in estimated savings of approximately 6 tonnes of CO2 in 2018.

The overall picture of all Terna's environmental data is available for download here.