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The relationship between the electricity grid and biodiversity is very complex and varies depending on the phase of the lines’ life (being built or already existing) and on the type of territory they cover.
In some cases, electricity lines may in fact represent a collision risk for birds or a fire risk for the surrounding vegetation but also an opportunity, especially in the areas of intense cultivation, for biodiversity concentration.

The attention to biodiversity is particularly high when the lines cross through protected areas.

Considering all of the types of protected areas defined by the Legislator (national and regional parks, national and regional reserves, SCI – Sites of Community Interest, SPA – Special Protection Areas, that together cover over 20% of the Italian territory) and eliminating the overlapping areas, 10% of Terna’s electricity grid (6,024 km) crosses a protected area for stretches varying from a few hundred meters to some tens of kilometers.

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

Courses of action

Terna's commitment for biodiversity is divided into three aspects:

The importance of preserving biodiversity by adopting the aforementioned mitigation hierarchy is taken into consideration at the earliest stages of the planning process. The prevention of negative impacts is based above all on full compliance with biodiversity protection regulations. In particular, these concern:

- the Strategic Environmental Assessment (SEA) procedure introduced by EU Directive 2001/42/EC and transposed by Italian Legislative Decree no. 152/2006, Part II. By taking a top-down approach to planning decisions with the aim of “contributing to the integration of environmental aspects in the development of plans and programmes”, Terna is able to promote a sustainable and environmentally compatible approach to the development of the electricity grid shared with local government and regional authorities;

- the Environmental Impact Assessment (EIA) procedure. This represents another safeguard both in the prevention phase and in the implementation of the necessary mitigation or monitoring measures. In fact, the organisations which verify that the project has been executed correctly also monitor compliance with provisions, thereby guaranteeing the utmost protection and attention for the environment;

- the implementation of the European “Habitats” Directive (92/43/EEC) and “Birds” Directive (79/409/EEC). In line with the “Guidelines for the management of Natura 2000 sites” issued by the Ministry for the Environment and Protection of the Land, Terna subjects its activities to Environmental Impact Assessments (EIAs) in order to identify, assess and mitigate any interferences with surrounding ecosystems.

The observance of national and EU legislation is supported by a number of additional voluntary initiatives implemented by Terna to ensure maximum protection for biodiversity. These include:

- the strategic partnership between Terna and the WWF, which involves integrating the WWF conservation strategy criteria in the planning of new lines;

- Terna’s use of the selection criteria for the most suitable environments for new infrastructure, known as the ERPA location criteria (Exclusion, Repulsion, Problematic nature, Attraction). According to this set of criteria, areas are classified based on their suitability to host the electricity infrastructure. The use of GIS technology (Geographic Information System) enables the comprehensive consideration of all information relating to the land use and any protection restrictions (territorial, naturalistic, cultural, landscape, etc.) and enables the identification of possible sustainable locations for the development of the NTG.

This approach enables construction works in areas of particular interest or value (such as protected areas or World Heritage Sites) to be kept to a minimum, as well as minimising the impact on the environment and biodiversity in general.

Furthermore, in accordance with internal procedures, the preferred solution is selected based on accurate surveys and environmental reports, including but not limited to geological and archaeological surveys, habitat assessments and IUCN species assessments. Each project is supervised by a multi-disciplinary team of internal professionals, aiming to optimise technical decisions and mitigate the impact of the infrastructure on the surrounding environment.

The impact on biodiversity at the building stage concerns construction site works, particularly the opening of routes in order to erect pylons, excavate earth and remove residual materials. Again, activities are carried out in strict compliance with environmental protection regulations and any provisions, adopting the best solutions to limit the effects on biodiversity and monitoring their effectiveness over time.

Terna manages the environmental impact of its construction works through a specific operating procedure that entrusts verification and control activities to a qualified environmental expert, who also supervises the activities carried out by contractors.

In terms of the relationship between existing lines and biodiversity, the main courses of action include:

- the study of the interaction between electrical lines and birdlife. In 2008, through an agreement signed with the Italian Bird Protection League (LIPU), a partner of Birdlife International, Terna launched a scientific evaluation programme to assess the significance of bird collisions with transmission lines, aimed at identifying the environmental conditions that influence the risk of collision and enabling the proposition of appropriate mitigation measures. Furthermore, Terna has worked with internationally respected external ornithologists for over 20 years;

- the installation of various types of deterrents, devices whose colour and shape, as well as the noise generated when blown by the wind, increase the visibility of the shield wire;

- vegetation control. When implementing these activities, which are required to prevent vegetation from coming into contact with conductors which can lead to problems for the electricity service and, potentially, negatively impact biodiversity (fires), the surrounding environment must be taken into close consideration. Terna adopts strict criteria in the selection of its suppliers and has commissioned a study of alternative systems, such as planting plant species with differentiated growth in order to ensure security without having to resort to pruning the vegetation.

Terna, in partnership with environmental organisations, has for some years been working on projects that aim to develop alternative uses for power lines. The most important, carried out in collaboration with Ornis italica, is the “Nests among the pylons” project. This involves the installation of nest boxes, followed by annual surveys of the species that occupy the nests and the results of the breeding season. The project regards many species, including: the kestrel, peregrine falcon, scops owl, cuckoo, common roller, bat and stork.

From the very beginning, these artificial nests have attracted numerous birds. Over time, the presence of raptors increased further.

By ringing the birds, the researchers of Ornis Italica have discovered that kestrel couples have a tendency of going back to the same nest, from season to season.
Launched in 2015, the GIS survey (localisation using geographic coordinates) of the installed nests is still in progress, with 384 already recorded.

Georeferenced nests 31 december 2018
Species concerned(1)
number of nests
of which in protected areas
Abruzzo 30 0 Kestrel
Calabria 30 23 Kestrel
Campania 1 0
Emilia-Romagna 95 31 Kestrel, scops owl, cuckoo, European roller
Lazio 47 14 Kestrel, scops owl, European roller
Lombardy 15 0
Piedmont 54 25 European roller
Puglia 72 0
Sicily 30 10
Trentino-Alto Adige 8 0
Veneto 1 1
Total 384 104

(1) The species concerned are identified according to the type of nest installed and the subsequent monitoring. However, it cannot be ruled out the nests may be used by other species that have not been identified.

The “Birdcam” project completes this project, which provides for the installation of television cameras on artificial nests to follow the birds’ reproduction period online on Terna’s website and on

The European roller

The concurrence of Terna’s electricity line routes with the migratory route of the European roller, a small bird of African origin, has stirred the interest of researchers from Ornis Italica, - a scientific association with which Terna has been collaborating for years on the projects “Nests on Pylons” and “Birdcam”.

In 2009, they installed some trial bird nests. Favored also by the location of the line in an uncontaminated organic farming habitat, the experiment to repopulate this species, strongly reduced by the intensive use of artificial pesticides that eliminated the small insects necessary for their nourishment, was immediately successful.
With an almost 100% occupancy of the nests– now almost 50 in number– and an average of 5 eggs hatched per nest, the bird population transiting through our regions has increased over 10% per reproductive season.

The ringing of the offspring born in 2009 has confirmed their return to the same nests this year: an extraordinary fact considering the thousands of kilometers covered by the birds during their annual migration.

Our case studies

The white stork

The white stork (Ciconia ciconia) is a migratory species found in the central-euro-asian mediterranean area: in fact it nests in Europe (Italy, France, Austria and Switzerland), in Asia Minor (Turkey) and in North Africa and spends the winter south of the Sahara Desert.

The white stork (Ciconia ciconia) is a migratory species found in the central-euro-asian mediterranean area: in fact it nests in Europe (Italy, France, Austria and Switzerland), in Asia Minor (Turkey) and in North Africa and spends the winter south of the Sahara Desert.
The unbidden return of the stork to Italy - at first just passing through in spring and autumn and then staying during breeding season - began in the fifties and since then there has been a slow but steady increase to the point of there being 160 breeding pairs in 2005 with nests in Piedmont, Lombardy, Veneto, Friuli-Venezia, Emilia-Romagna, Tuscany, Calabria, Puglia, Sicily and Sardinia. 14% of the total population was concentrated in Piana di Gela in Sicily.

When migrating, storks are a gregarious species and form large flocks, but during the breeding season they become territorial: solitary couples, or local clusters, build their nests on trees, buildings, pylons or other artificial structures.
The first spontaneous nest in Tuscany was built in 2005 when a couple, made up of a female from the Carapax Center in Massa Marittima (GR) and a wild male, settled on a pylon in Fucecchio (FI), successfully breeding even in the following years.

Since 2013, in Prato, a stork pair have been nesting and breeding on one of our pylons and, having been brought to our attention by the volunteers from the local Natural Sciences Center, collaboration has been formed with Terna.
Thanks to the webcam behind the nest it is possible to see all the phases of the reproductive cycle, from when the eggs are laid to their hatching to the fledging of the new borns.
The presence of this stork's nest has lead to an environmental education program being instated in the local schools where, last year, the pupils chose the names "Nuvola" (Cloud) and "Tuono" (Thunder), drew and photographed them and took part in the "Pylons, Artificial Trees and Biodiversity" competition.

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Biodiversity and Electricity Lines

The 6th CSR Fair “Dal dire al fare” (From saying to doing) was the setting of the seminar “Biodiversità e linee elettriche, una convivenza possibile”, (Biodiversity and Electricity Lines, a possible cohabitation) organized by Terna to take stock of the situation regarding the challenges of nature conservation and the results, in some cases extraordinary, of the project “Nests on Pylons”.

Attending the seminar were, among others:

Alberto Marchi presented The next environmental issue for business; a study by McKinsey & Company conducted on over 1,500 executives of the major world companies to understand the main concerns on environmental sustainability and measure their impact on the reputation of a company. In addition to established themes such as climate change, the management of water resources and waste, the research showed that 9% of the top managers interviewed consider biodiversity protection a company priority and that about 60% of those interviewed consider it an opportunity.

More generally, over 50% of the companies surveyed consider biodiversity protection a competitive and marketing edge and for 52% the communication of actions taken to protect the environment is a distinctive element of business operations.
Francesco Petretti has indicated the main threat to the future of biodiversity in the degradation and transformation of ecosystems, in addition to climate changes; he also emphasized how traditional conservation strategies based on the creation of protected areas are not sufficient to prevent extinction phenomena at both a local or global level.

Conservation strategies must now act outside the protected areas with procedures that guarantee the maintenance of biodiversity even in “disturbed” environments.
The challenge of the next decade could be won by reducing the ecological footprint of human activity, protecting the eco-systems and their vitality and redeveloping on a small, medium and large scale the degraded habitats.

With regard to bird life, the scarcity of suitable sites for natural nesting and the risk of predation of the offspring led to placing artificial nests and their monitoring as the correct action to protect biodiversity.
The projects “Nests on Pylons” and “Birdcam” carried out by Terna in collaboration with the scientific association Ornis Italica move in this direction since they exploit the natural disposition of various bird species, mostly birds of prey, to use pylons as look-out towers and places to nest..

Each year over 1,000 newborn birds take flight from more than 500 artificial nests installed in Tuscany, Lazio, Umbria, Emilia-Romagna and Lombardy. They are for the most part kestrels although there are plenty of scoops owls, peregrine falcons, owls, jackdaws, and in recent years, European rollers.

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