Rinnovabili eolico renewables eolic Pexels Johan Bos

C is for Connections

Monitoring requests for connection of renewable plants to the national transmission grid, managed by Terna, is essential to identify trends and areas with a greater concentration of plants and to then plan development of infrastructure and all tools required to achieve the ambitious international targets.

The connection of an electricity plant to the national transmission grid, managed in Italy by Terna, follows a process defined and governed by ARERA, the Italian Regulatory Authority for Energy, Networks and Environment. According to Article 3 of Italian Legislative Decree 79/99, Terna is obliged to connect all applicant parties to the electricity grid; in particular, it is responsible for high-voltage and extra-high-voltage connection, namely of plants with power at 10 MW or higher. The connection request is the first step in a process that ends with creation of the plant and connection to the grid.

In recent years the development and diffusion of renewable sources has made radical changes to the Italian electricity system, historically based on energy production from mostly traditional thermoelectric. The present, and especially the future, is increasingly greener and the challenging European decarbonisation objectives set out in the Fit for 55 programme have already defined the target we must reach in Italy: in addition to reducing greenhouse gas (GHG) emissions by at least 55% compared to 1990 levels, by 2030 we must install around 70k MW in Italy of new capacity from renewables, in particular wind and photovoltaic power. This will make it possible to cover at least two-thirds of Italian electricity consumption with energy produced from clean sources, doubling the current amount. An intermediate step towards 2050, when climate neutrality (“net zero”) is envisaged.

Rinnovabili Renewables Terna

A photovoltaic plant close to national electricity power lines (photo by Terna)

But where are we at in this energy transition process? How is the development of renewable energy proceeding in Italy? An interesting point comes from Econnextion, the new dashboard that Terna has created in collaboration with the Ministry of the Environment and Energy Security. It is a one-of-a-kind digital platform exclusively dedicated to requests for connection to the electricity grid of renewable plants in Italy: an enormous amount of data is grouped by energy source and expressed in terms of power, displayed in graph and table form.

The tool seeks to represent a point of reference for all stakeholders and sector operators. Indeed it makes it possible to view and consult, for the first time, all information about the geographic location and authorisation status of new onshore and offshore wind initiatives and photovoltaic projects across Italy. And to discover, for example, that the number of connection requests to the Terna grid has surpassed 4,400 applications for a total power of over 300k MW (in this case the figure refers to January 2023 and will be updated quarterly). This encouraging number demonstrates the great interest of sector operators to invest in renewable plants. Especially in the South and the largest islands, geographic areas with a high availability of primary energy resource (wind and sun) and where the majority of these initiatives are concentrated: according to the data, Apulia, Sicily and Sardinia are at the top of the “special” ranking, followed by Basilicata, Lazio and Calabria.


Econnextion, the digital platform for renewable connection requests to the national transmission grid, available on Terna.it (photo by Terna)

Terna’s engineers have created this platform using an innovative geopositioning system for all connection requests. The result is a map of Italy that proves to be particularly useful in identifying the trends and areas with a greater concentration of plants and, as a result, to plan in a coordinated manner the development of all infrastructure required to achieve the electricity system decarbonisation targets in the most efficient and sustainable way: renewable generation plants, energy storage systems and above all, electricity grids.

The latter represent strategic infrastructure for the energy transition in that they are needed to be able to transport all renewable energy produced in the South towards the centres of highest industrial and civil consumption in the North of Italy, where the majority of Italian electricity demand is still concentrated.

The dashboard is formed of two sections. In “Connection Requests” it is possible to filter requests by source (solar, onshore wind, offshore wind) in an aggregated format (number, output and percentage distribution). Using the interactive map, details are displayed at a regional, provincial or municipal level, and, thanks to the search filters, all active requests in a certain municipality and their authorisation status, for example, can be selected, and renewable energy plant initiatives compared in various provinces or regions based on the so-called “General Minimum Technical Solution” (GMTS) produced by Terna. The other section “Fit for 55 Target” contains the most significant data relating to photovoltaic and wind (onshore and offshore) initiatives grouped by market zones, with reference to the targets set by the European package for 2030.

Centro controllo Torino control room Terna

A control center of the national electricity system in Turin (photo by Terna)

Of the various technologies that characterise the evolution of the connection requests received by Terna on the high- and extra-high-voltage grid, offshore wind technology deserves a special mention, since has only recently been developing in Italy. There are currently significant numbers of connection requests and the reason for this development essentially lies in the improvement to the technology, which is reaching a maturity that will also make it applicable in areas where the seabeds are extremely deep.

For these plants, the connection solutions present major technical complexity, also due to their size and therefore the power at play. In order to collect useful information about the technologies currently available, development prospects and international best practices, Terna has conducted a careful technological survey involving suppliers and other European grid operators with more experience in connection solutions for offshore wind power plants: this has already made it possible to issue connection solutions by implementing an electricity grid planning methodology specifically for offshore wind. It is therefore essential to carefully monitor the evolution of these events in order to anticipate and even make appropriate updates to the planning and development of the works and the essential infrastructure projects for a full and secure integration of renewable sources into the electricity system.