Main Information

Working within the National SEA Group, Terna and the Regions agreed on a system in which the application of the criteria leads to a characterisation of territory in four classes:

1. EXCLUSION: areas in which any kind of construction is excluded.
2. REPULSION: areas where it is preferable not to construct, unless there is no alternative or there are only alternatives that are even less environmentally compatible.
3. PROBLEM: areas in which the landscape is problematic and which therefore require further territorial analysis to establish whether the level of problems can be overcome or it is necessary to find alternatives. Unlike the other criteria, there is a need for further study and the absence of an automatic mechanism of an a priori assessment.
4. ATTRACTION: areas to favour whenever possible after checking the area’s load capacity (e.g. where bundling is possible).

To be able to work with this scheme, Terna established an extensive database of cartographic information, which is exceptional in Italy. Keeping the database updated is a continuous effort. The database today has a size of about five Terabyte and holds information on 1,500 different layers. It covers data regarding geological, hydrogeological, nature environment, and landscape aspects. Terna has agreements with the Ministries for the Environment and the Ministry for Landscape, but also with individual regional and local bodies, to provide them with updated data. Data collection furthermore goes down to municipal offices to be able to cover specific local aspects.

Information contained in the database is applied on the areas under study via an automated Geographic Information System (GIS). The system applies set weights for each considered aspect, assigning a numeric value to the siting criteria. This is an essential element as it ultimately determines how an analysed territory is classified. The weights are therefore set by the National SEA Group and cannot be changed to avoid opportunistic adjustments on a local level. The data is shared so that regional bodies are able to repeat the territory analysis and check the results.