The European electricity sector is undergoing a steady transformation, brought about by the massive growth in renewable energy resources and the European Union’s commitment to becoming carbon-neutral by 2050 as per its green deal. In line with this, Italy’s National Energy and Climate Plan has set very ambitious targets for renewables by 2030, aiming to have renewables account for 30 per cent of total energy consumption and 55 per cent of electricity generation. To achieve these targets, around 40 GW of new renewable capacity, mostly wind and solar, will need to be installed in the country by 2030.
The country’s transmission system operator (TSO) Terna S.p.A., which owns over 99.7 per cent of the national transmission grid (NTG), is playing a key role in accelerating the energy transition and decarbonisation in Italy through sustainable investments aimed at integrating renewable sources to increase the efficiency, safety and resilience of the electricity grid.
The recently unveiled Development Plan 2021 for the national electricity transmission grid mirrors these ambitious targets with planned investments that are 25 per cent higher than the previous 10-year development plan.
2021 Development Plan for the National Electricity Transmission Grid
In July 2021, Terna released its Development Plan 2021 for the NTG, in which it has pledged to invest a record Euro 18.1 billion in the country’s power grid over the next 10 years to meet the demands of the energy transition and economic recovery. The key drivers for projects included in the plan are decarbonisation, market efficiency, security of supply and sustainability. The investments will aim to integrate energy produced by solar and wind projects in the south with consumption centres in the north as well as enhance connections between the mainland and the islands. The investments will facilitate the integration of about 40 GW of renewable generation by 2030; demolish 4,600 km of obsolete transmission lines (which is 800 km more than the previous plan); result in an additional 6 GW of cross-border interconnection capacity; reduce energy losses by 2,000 GWh annually and cut carbon emissions by 5.6 million tonnes per annum (double that of the previous plan) due to improvements in the generation mix and lower network losses.
Terna has planned over 30 new infrastructure projects, giving high priority to all projects deemed strategic for the entire national electricity system. Several projects of national interest are included in the development plan, and are scheduled to be completed in the early years of the plan. These include the 380 kV Colunga-Calenzano power line, the 380 kV Chiaramonte Gulfi–Ciminna line, the 80 kV Paternò-Pantano-Priolo power line, and the 380 kV Bisaccia-Deliceto line.
Among other projects that will come into operation during the period of the plan is the Euro 3.7 billion Tyrrhenian link. This is a 500 kV high voltage direct current (HVDC) link that will connect Sardinia to Sicily and the latter to Italy’s mainland. It will contribute to the phase-out of coal-fired power plants in Sardinia and allow for the retirement of thermoelectric plants in Sicily while enabling renewable development.
Terna also plans to commission the 280 km undersea HVDC Adriatic Link between Abruzzo and Marche by 2028. The Euro 1 billion project will be imperative for the integration of wind power and solar PV power produced in southern Italy with consumption centres in the north.
The 380 kV Bolano-Paradiso 2 connection between Sicily and Calabria will allow the exchange of electricity between the island and the mainland to be increased to 2 GW, benefiting the clean energy developments planned for the south of the country. Another 380 kV power line has been planned between the areas of Montecorvino and Benevento. Over 70 km long, this line will help ease grid congestion in Campania and in the south in general.
A major portion of Terna’s past investments has been spent on the development and construction of interconnections with the neighbouring European countries. The 2021 Development Plan has approved over 6 GW of new interconnection capacity, to be added during the next decade. Planned investments in cross-border interconnections will allow Italy, given its strategic position in the Mediterranean and in the European electricity system, to increasingly assume the role of the energy hub of the Mediterranean – a brid-ge to the Balkans, Central Europe and the North African countries. Its position will be strengthened with the advancement of new interconnection projects along with internal network reinforcements.
In the latest plan, investments in three new interconnections with Switzerland, Greece and France have been finalised. The first is a new 1,000 MW connection between Italy and Switzerland, which has been planned at an investment of over Euro 1.2 billion. The TSO also plans to invest around Euro 750 million in the construction of a new 500 MW and 200 km long undersea cable with Greece. The project will double the current exchange capacity between the two countries and encourage greater integration of renewable sources.
The Sa.Co.I.3 project has also been confirmed in the 2021 Development Plan. The project involves the renewal and modernisation of Sa.Co.I.2, the existing HVDC electrical connection between Sardinia (Italian island), Corsica (French island) and the Italian mainland. It will be created using existing assets, with the modernisation of bipolar conversion stations and substitution of underground and undersea cables. It will allow the use of a total transport capacity of up to 400 MW. These interconnections, together with the other planned power links with Tunisia and Austria, will allow Italy to strengthen its role as an electricity hub in Europe and the Mediterranean area.
Terna is taking bold steps to upgrade the transmission network in the country, making the grid resilient for renewable energy integration. It is also actively engaged in innovation, focusing on new technological solutions and the integration of digital measures to modernise the grid.
In November 2020, Terna launched its 2021-2025 Industrial Plan, as per which it plans to invest over Euro 8.9 billion in the next five years. A major share of this will be invested in the development of the national grid with the aim of increasing the transmission capacity between the different market zones. Around Euro 2.4 billion will be invested in renewing and improving the efficiency of Terna’s assets, to be spent largely on improving service quality and processes, and developing sustainable grid solutions. Also, Euro 900 million has been earmarked for initiatives such as new digital systems for management, diagnostics infrastructure for drones, advanced IoT sensors, SF6 free high voltage electrical equipment, robots and satellites for remote monitoring of power lines and power stations, and advanced methods of processing big data. The TSO is engaged in the development of smart charging and vehicle-to-grid (V2G) applications with various electric mobility stakeholders to enable the provision of grid services from electric vehicles. It has also developed a blockchain platform to facilitate the participation of small distributed resources in providing flexibility for the system, together with other European TSOs.
Terna is also in the process of finalising the system to give real-time estimates of the main electrical data relating to load and distributed generation. The TSO is also making efforts to optimally manage and increase the capacity of the existing transmission infrastructure through technologies such as synchronous compensators, reactors, and flexible alternating current transmission systems; as well as dynamic rating techniques. Terna is involved in the Horizon 2020 OSMOSE project, wherein it uses the grid between Puglia and Basilicata to test the coordinated management of flexibility resources provided by grid devices, industrial loads, and conventional and renewable resources to minimise the reduction of renewables through new energy management algorithms.
The TSO has also been conducting research in the field of utility-scale electrochemical storage, and numerous tests have been conducted to identify the potential and margins for improvement of conventional technologies (lithium, ZEBRA and flow batteries) and other types such as supercapacitors.
Meanwhile, it is deploying grid-connected storage systems to optimse renewable generation and ensure increased security management of the electricity system. In this regard, the TSO awarded the Enel Group contracts for 59.2 MW of capacity in December 2020. The capacity will be supplied by the fast reserve units (FRUs), which includes the possibility of combining an electrochemical storage system with EV charging infrastructures and V2G solutions. From January 2023 up to December 2027, these units will provide ultra-fast response service in less than one second. Earlier, in February 2021, Terna awarded Greece-based industrial company Mytilineos S.A. two contracts to develop 26 MW of battery energy storage capacity in southern Italy by 2022. The systems are expected to start providing fast reserve services to the Italian grid from 2023 until 2027.
Terna is collaborating with its counterparts in other European countries to achieve the ambitious European decarbonisation goals. In July 2021, Terna, along with seven other TSOs, released a joint paper to highlight and strengthen its key role in the region’s energy transition from a system that mainly uses fossil fuel sources to one that is increasingly cleaner and more efficient. The collaboration has a specific purpose – to analyse and evaluate how the activities of the grid operators contribute to the planned decarbonisation, and the achievement of carbon neutrality and sustainability of the electricity system. Earlier, in February 2021, Terna collaborated with six other TSOs (Germany’s 50 Hertz Transmission GmbH and Amprion, Sweden’s Svenska kraftnät, REE, RTE and Norway’s Statnett SF) for the launch of Eurobar, an initiative to interconnect offshore wind platforms across Europe through an interlinked offshore network or busbar alike system.
The way forward
The future of Italy’s energy transition is heavily dependent on more efficient digitised grids as the transition will bring technical and operational grid complexities. The country’s transmission network is already witnessing an increase in network congestion due to renewable energy sources. Hence, transmission investments are imperative to support Italy’s changing generation mix. The projects envisaged in Terna’s 2021 Development Plan will be fundamental in this regard. With huge renewable capacities planned to come up in the country, a smooth transition from fossil fuels, with the strengthening of transmission capacity, cross-border interconnections and overall infrastructure, will be the way forward for the country.