Fenno-Skan 2

Two months after it opened, Fenno-Skan 2 was out of action. In February 2012 a German ship dropped anchor on top of the new cable and damaged it. According to the Fenno–Skan article on Wikipedia, the outage cost Finnish consumers and industry an estimated €80 million in higher electricity prices over those two months, which gives a rough sense of what the link was worth to the market.

It had been built because the Finland–Sweden border was short of capacity. Fingrid and Svenska kraftnät ran the project jointly, and the stated aim, as T&D World reported at completion, was to improve the working of the Nordic electricity market considerably. The new cable raised transmission capacity between the two countries by 40 percent.

The route shares its Finnish end with Fenno-Skan 1 at Rauma. From there roughly 200 km of cable crosses the Gulf of Bothnia, and the Swedish converter stands at Finnböle, built at the same time as the cable. Nexans made the cable at its Halden factory in Norway; ABB supplied the converters. A trial period began on 15 November 2011, when part of the capacity was already open to the market, and full capacity followed on 16 December 2011.

The cost is quoted two ways. T&D World gave about €315 million for the whole construction, while Wikipedia cites €150 million. The two numbers cannot describe the same scope; the larger one was published at completion and is the one to quote.

Fenno-Skan 2 is the newer half of a pair that is about to change. Fingrid and Svenska kraftnät plan to replace the 1989 cable with an 800 MW Fenno-Skan 3 by around 2038. When that happens, this link becomes the older of the two, and the gulf will carry 1,600 MW of HVDC on two cables of equal size.