What's a transmission project?

All projects to build or renovate electricity transmission assets go through a series of steps, from assessing the need for infrastructure to commissioning. Discover the main life-cycle steps of a transmission project.
The text, pictures and videos illustrating real-life projects were provided by project promoters.
Step 1

Identifying the needs

Step 2

Identifying solutions to address the need

Step 3

Preliminary design of a project & Cost-benefit analysis

Step 4

Inclusion of the project in the National Development Plan and in the TYNDP

Step 5

Applying for European “Project of Common Interest” status

Step 6

Engineering design and permitting process

Step 7

Financing and Final investment decision

Step 8

Construction and commissioning

Step 9

Operation of the new infrastructure

Step 1

Identifying the needs

The first step, before developing a project, is to identify the needs for reinforcement of the transmission network. TSOs assess needs at national level on a regular basis. This assessment is completed by studies of needs at regional and pan-European level, carried out by ENTSO-E in the bi-yearly System needs study and Regional investment plans.

Assessing needs at national, regional and pan-European level allows to identify needs that may not have been identified with a national-only approach, or that would have been defined in a different way. It is especially important as RES development is triggering needs for an increasingly interconnected pan-European network, allowing electricity from RES to flow across borders.

Needs may be triggered by a wide list of factors, including changes in the generation portfolio and in the localisation of generation units, network stability and frequency issues, ageing infrastructure … The solutions to the needs are equally diverse and can come in the form of multiple technologies including other solutions than transmission lines, hence the importance of step 2.

Case Story

TYNDP 2020 Future projects, responding to power system needs in 2030 and 2040

As part of the TYNDP, ENTSO-E investigated future power system needs in the 2030 and 2040 horizon. For the first time in the TYNDP 2020, project promoters were given the opportunity to propose new projects that address some of the identified needs. Nine projects were proposed, all in the very long term with a commissioning date after 2035.

These include two projects on the Bulgaria-Turkey and Greece-Turkey borders, where the System needs study identified needs for capacity increase of 1500MW in 2030 and 2040. Both projects have the potential to improve the stability of the connection of the Turkish power system to the Continental Europe synchronous area, allow integration of renewable energy and support the convergence of electricity market prices between Greece, Bulgaria and Turkey. Two other projects address needs on the Greece-North Macedonia border, with either the refurbishment of an existing interconnector or the building of a new one expanding also to Bulgaria. A last project in South-Eastern Europe plans for new interconnectors between Lybia, Northern Greece and Albania.

Further North, another identified need that was not already addressed by an existing project, is located on the Serbia-Hungary border. Promoters of the “Pannonian Corridor” project expect that it has potential to positively increase market integration in the region, while vastly enhancing security of supply and allowing for integration of renewable energy sources. In the Baltic, a project proposes to connect Sweden to Latvia via the Island of Gotland to integrate further renewable generation, reduce the current level of curtailed energy and increase market integration in the Baltic Sea region. Finally, a last transmission project proposes to connect 700MW of offshore wind in Ireland.

The only storage project proposed in this window, the Online Grid Controller “PSKW-Rio” in Germany, answers the need to balance wide areas of the distribution grid and improve renewable energy grid feed-in, grid security and stability. The project could also support the management of fluctuating energy production from renewable energies and therefore significantly reduce carbon footprint as well as operation and maintenance costs.