Step 9

Operation of the new infrastructure

Once the infrastructure is in operation, analysing its impact on system operations and markets allows to tell whether the benefits anticipated during the planning phase have been delivered. Promoters look at indicators such as, for example, for a cross-border project the price difference on the border before and after the commissioning of the project, the congestion …

The evolution of the amount of electricity exchanged on the border is also a strong indicator of the relevance of a new interconnector, as it shows its usefulness to stakeholders on electricity markets.

Comparing the actual benefits delivered by a project with the benefits anticipated during the CBA phase also allows to gather valuable feedback on the CBA process, and may lead to rethinking the CBA methodology and/or the building process of the scenarios.

Case Story

Santa Llogaia – Baixas: Benefits identified in the TYNDP surpassed one year into operation

Video: “Inelfe — Interconnexion électrique France-Espagne (FR)”

Video: “Fin du percement de la galerie technique de l’interconnexion électrique France-Espagne”

Santa Llogaia – Baixas was a globally pioneering project, connecting France to Spain with a 65-km-long HVDC 320 kV underground cable under the Eastern Pyreneans, with AC/DC converters at both ends. Cost-benefit analysis performed in TYNDPs 2010 to 2014 identified high potential for increase in socio-economic welfare, as the project allows the use of more efficient and cheaper technologies and avoids spillage of RES especially in the Iberian Peninsula. The project was a PCI and benefited from a European coordinator, which help with the smooth implementation of the project.

One year after its commissioning in 2014, the benefits anticipated in the TYNDP were confirmed and even surpassed. It is difficult to draw an exact comparison of the benefits expected with those effectively obtained, because of the horizon year (TYNDP studied the project’s benefits in the year 2030), and because some of the variables are not caused only by the new interconnection but by the evolution of the energy mix, climatic conditions, etc. However, other variables used in the TYNDP process provide indications:

  • The net transfer capacity has more than doubled since the new interconnection commissioned, reaching expected values.
  • There was a rapid uptake for the additional interconnection exchange capacity. This new transfer capacity was swiftly harnessed by the various stakeholders in the electricity market. In fact, physical exchanges increased from 8,02 TWh to 15,17 TWh in just one year, by almost 90 %.
  • The increased capacity allowed a higher convergence level of the day-ahead markets. In the hours with congestion from France to Spain the spread was reduced from 17,96 to 12,12 €/MWh, and from Spain to France from 10,98 to 8,13 €/MWh.
  • Europe-wide, congestion periods decreased significantly, while maintaining high performance levels. After one year in operation congestion still occurred 75 % of the hours at the French-Spanish border (87 % one year before the commissioning).

The trends obtained in the first year in operation remain in the same range today, with some yearly variations depending mainly on the climatic conditions and network availability. For instance, the spread in 2019 was 11,92 €/MWh from France to Spain and 6,5 €/MWh from Spain to France, the congestion was 65,9 % and the congestion rent 178,4 M€, in a range similar to previous years.

Santa Llogaia – Baixas project (REE, Rte)

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