Sweden has the largest electricity generation base in the Nordic region and is its largest net exporter. The system is anchored in hydro, nuclear, and a growing wind base, and import dependence has fallen by roughly a third over the past two decades. The defining feature is internal rather than external: the geographic mismatch between generation and demand. Hydro and onshore wind sit predominantly in the north, the largest industrial and population centres are in the south, and the country operates in four bidding zones with persistent and large price differentials between them. Southern Sweden (SE3 and SE4) has the tightest electricity adequacy margins of any Swedish price zone. The May 2026 government order to halt Konti-Skan Connect, the planned renewal between south-western Sweden and Denmark, marked the point at which the political constraint on cross-border transmission renewal had direct infrastructure effects.
The Swedish system is also distinctive for its dispersed exposure across coastal and island geographies. Gotland combines a large military presence, a civilian population, and growing industrial energy demand on a single island connected to the mainland by two HVDC cables, with a new connection contracted for 2030. Because the existing connections are DC, Gotland runs as its own system frequency, with stability dependent on converter equipment at both ends. Öland is connected through a thinner transmission spur into the SE4 zone where adequacy margins are tightest. Institutionally, Swedish energy preparedness is concentrated in the Civil Contingencies Agency (MSB), the operational counterpart to Finland’s NESA in the 1992 Finland–Sweden security of supply agreement. Sweden has consistently met its EU and IEA oil stockholding obligations.
Key challenges
The north-south transmission bottleneck. The persistent price spread between northern and southern bidding zones is the visible expression of a structural transmission constraint. The northern industrial buildout (green steel, battery manufacturing, hydrogen production) is adding load in a part of the country where transmission to demand centres in the south has not kept pace.
Gotland concentration risk. The combination of a large military presence, growing industrial demand, an autonomous system frequency dependent on converter equipment at both ends, and a high local wind share creates an unusually concentrated profile of operational risk on a single island. The new mainland connection due in 2030 changes the capacity picture without changing the structural concentration.
Capacity adequacy in SE3 and SE4 during cold and low-wind events. The same conditions that came close to a loss-of-load situation in Finland during winter 2025–2026 strain SE3 and SE4 from a different angle. Nuclear reactor maintenance schedules, wind variability, the halted interconnector renewal, and the planned phase-out of older thermal generation all converge on southern Sweden as the most likely site of a near-term Nordic adequacy event.