NordSyd

NordSyd (North-South) is Svenska kraftnät‘s flagship transmission grid initiative to increase electricity transfer capacity from northern to southern Sweden. It addresses the fundamental Bidding Areas imbalance: surplus generation in SE1–SE2 and deficit consumption in SE3–SE4.

Four branches

The initiative consists of four parallel reinforcement routes through central Sweden:

Additionally, the Midskog–Malsjö double 400 kV line project (planned 2035) is part of the northern NordSyd corridor, connecting into the Karlstad branch.

Capacity targets

Svk’s Planering för ökad elanvändning (February 2025) sets explicit capacity targets for the two main internal snitts:

• Snitt 1 (SE1–SE2): target 7,500 MW by 2045 — up from 3,300 MW today (+4,200 MW)
• Snitt 4 norrgående (SE3–SE4): target 3,600 MW by 2045 — up from 2,800 MW today

These targets are in a prior government assignment report and are directional planning benchmarks, not binding commitments. (Source - Svk Planering för ökad elanvändning (2025))

Why it matters

The north-south bottleneck is the single most consequential constraint in the Swedish electricity system:

• It causes persistent price differences between northern and southern bidding areas
• It limits the ability to use northern hydropower and wind to serve southern demand
• It constrains new industrial connections in the north (green steel, hydrogen, data centers) by limiting how much generation can be exported south
• It creates Congestion Management needs that drive demand for Flexibility

NordSyd, combined with reinvestments that also increase capacity, aims to substantially increase intersection 2 and intersection 4 transfer capacity through the 2030s.

Timeline and investment

NordSyd projects are among the largest items in Svk’s SEK 225 billion investment plan. Individual components span from contracting phase (construction imminent) to under consideration (still being studied). Key packages by estimated cost:

• Kustpaketet (Coast package): SEK 17 billion
• Midskog–Malsjö: SEK 14 billion
• Inlandspaketet (Inland package): SEK 13 billion

Full completion extends into the late 2030s–early 2040s. (Source - Svk Network Development Plan 2026-2035)

Relationship to flexibility

NordSyd is the physical infrastructure solution to the north-south congestion problem. Flexibility is the operational and market-based complement:

• Until NordSyd is built: flexibility mechanisms (demand response, storage, conditional connections) are the primary tools for managing congestion within existing capacity
• After NordSyd: flexibility remains necessary for real-time balancing and managing remaining or new bottlenecks, but the structural congestion is reduced
• During construction: grid outages for construction can temporarily reduce available capacity, increasing the need for flexibility during the build-out period itself

The long lead times (10–15 years) for transmission projects like NordSyd fundamentally explain why Sweden cannot simply “build its way out” of grid constraints — flexibility is a necessary bridge.

DSO impact during construction

NordSyd construction creates a specific temporary problem for DSOs whose regional grids are connected to the affected transmission corridors. E.ON Energidistribution‘s DNDP explicitly identifies this: during 2027–2030, Svk’s NordSyd construction will cause E.ON’s Gävleborg and Västernorrland regional grids to be more heavily loaded than normal, as power flows reroute through alternative paths. This temporarily reduces the capacity available for new consumption connections in those counties.

When the NordSyd projects are completed (2032–2035), E.ON’s available capacity is expected to return to pre-construction levels — and then exceed them as NordSyd adds transfer capacity.

Practical implication for the 2027–2030 period: the capacity ratings (B/C) in Gävleborg and Västernorrland in E.ON’s DNDP are not caused by local network weaknesses but by the upstream stamnät construction. This is a temporary constraint with a defined resolution date. (Source - E.ON Nätutvecklingsplan 2025-2034)

Vattenfall’s NordSyd Västeråsbenet involvement: Vattenfall Eldistribution‘s DNDP includes Projekt 11 — Kapacitet Västmanland (NordSyd Västeråsbenet) as a major investment project — licence approved, commissioning 2025–2030. This is Vattenfall’s regionnät investment to accommodate the Västeråsbenet component of NordSyd, which passes through Vattenfall’s Mellan area in Västmanland. Vattenfall’s assessment: with the NordSyd Västeråsbenet project completed (from 2028), the Mellan area meets need. Before 2028, the area has limited spare capacity from the overlying stamnät. (Source - Vattenfall Eldistribution Nätutvecklingsplan 2025-2034)