Fenno-Skan 1
Cross BorderOperational400 MW400 kV233 km1989
Also known as:FS1, Rauma–Dannebo (Rauma–Dannebo 400 kV DC), Dannebo–Rihtniemi
Status:Operational
Capacity:400 MW
Type:cross border
Expected Life:51 years
Website:www.fingrid.fi
Fenno‑Skan 1 is an HVDC subsea interconnector between Rauma (Finland) and Dannebo (Sweden) commissioned in 1989. Built as a monopolar ±400 kV link with sea/earth return and a total route of roughly 233 km (about 200 km subsea with a short onshore/overhead approach to Rauma), it was designed to accommodate...
Supply Chain (8)
Project Timeline (14)
2021Lifetime Extension
In 2021, Fingrid and Svenska kraftnät agreed to continue operating the Fenno‑Skan 1 HVDC connector between Finland and Sweden until 2040, effectively extending its operational lifetime beyond the 35–40 year end‑of‑life window (2024–2029) previously inferred for the link’s converter stations.
2 Dec 2019Operations Other
Following analyses of a potential new higher-capacity replacement link, Fingrid and Svenska kraftnät concluded in 2019 that market benefits before 2030 would be modest and that Swedish internal grid reinforcements were a higher priority, and therefore decided to focus on analysing the possibility of extending the lifetime of the existing Fenno-Skan 1 link beyond 2030. The planned lifetime extension study is intended to determine whether continued use of Fenno-Skan 1 is feasible and to inform the optimal timing of any future renewal of the link.
2018Early Development OtherStale
Fingrid and Svenska kraftnät planned to continue joint technical studies during 2017–2018 on options for replacing the Fenno-Skan 1 direct current connection, building on earlier investigations of route and capacity alternatives. These planned studies were intended to refine the technical basis for a future renewal project for the Fenno-Skan 1 link.
24 Oct 2017Early Development Other
By 2017, Fingrid and Svenska kraftnät had carried out investigations into replacing the Fenno-Skan 1 direct current connection either along its existing route or via the Kvarken area, and identified a replacement option with about 800 MW capacity that would increase market capacity by roughly 400 MW. Due to its technical advantages, a new link in the Kvarken area was being examined as the primary alternative for renewing the Fenno-Skan 1 connection.
6 Dec 2016Tyndp Listed
Licence: Inclusion in TYNDP 2016 as Project 239 – Fenno-Skan 1 renewal
The Fenno-Skan 1 renewal project, involving replacement of the existing 400 kV HVDC cable interconnection between Finland and Sweden with an estimated capacity of 500–800 MW, was included in ENTSO-E’s Ten-Year Network Development Plan 2016 as Project 239. The project is promoted by Fingrid and Svenska kraftnät and is framed as a future project that could maintain or increase the current 500 MW capacity of Fenno-Skan 1 towards the 800 MW level of Fenno-Skan 2.
1 Nov 2016Early Development Other
Svenska kraftnät and Fingrid jointly completed a cross-border capacity study in 2016 to evaluate the socio-economic benefits and feasibility of increasing transmission capacity between Sweden and Finland, driven in part by large price differences and the approaching end of Fenno-Skan 1’s technical lifetime. The study, documented in a report published on 1 November 2016, examined four alternative new connections to inform decisions on how to replace or supplement the Fenno-Skan 1 interconnector.
2013Major Maintenance
Around 2013, the original Fenno‑Skan 1 link underwent a major upgrade in which its control system was modernised to a fully digital MACH system and the converter stations were configured so that Fenno‑Skan 1, originally a monopolar link using sea return, could operate as part of a bipole with Fenno‑Skan 2, improving performance and reducing reliance on sea electrodes.
2013Grid Constraint Event
From 2013, the transmission power of the Fenno‑Skan 1 direct current cable was permanently limited to 400 MW due to its maximum voltage and submarine cable condition, leading Fingrid to reduce the available cross‑border capacity between Finland and Sweden and operate the link at only 80% of its 500 MW installed DC rating.
1998Capacity Upgrade
In 1998, the power rating of the original Fenno‑Skan HVDC transmission link between Finland and Sweden (Fenno‑Skan 1, owned by Fingrid and Svenska kraftnät) was increased as part of a series of cross‑border capacity investments, enhancing its transmission capability ahead of later reinforcements such as Fenno‑Skan 2.
1989Commercial Operations Full Power
Fenno-Skan 1, a 500 MW ±400 kV HVDC interconnector between Rauma in Finland and Dannebo in Sweden owned by Fingrid Oyj and Svenska kraftnät, was commissioned in 1989 and entered full commercial operation transmitting power between the two countries.