Source - Svk Network Development Plan 2026-2035

Full title: Network Development Plan 2026–2035 (Nätutvecklingsplan, NUP) Author: Svenska kraftnät Published: 2025 Raw file: raw/svk_natutveckling_nup_2026-2035_eng.pdf

Summary

Svenska kraftnät’s ten-year plan for the Swedish transmission grid. Describes the current state of the grid, drivers for expansion, planning methodology, scenario-based demand forecasts, and region-by-region investment plans. The document frames a massive scale-up of grid investment driven by electrification and the energy transition.

Key claims and data

Four motives for grid development

All transmission grid investments are categorized by motive:

Total planned investment 2025–2035: SEK 225 billion (~365 BSEK including projects beyond 2035). Grid investments are increasing sharply from ~5,000 MSEK/year historically to potentially 25,000+ MSEK/year.

Physical scale

• ~2,900 km of new lines planned
• ~40 new substations
• Reinvestment of 1,100+ km of lines and ~100 substations

Connection queue

The queue of applications to connect to the transmission grid is enormous:

• >175 GW total applied for input (generation) 2020–2025
• Of which 124 GW offshore wind and 17 GW onshore wind
• Swedish peak load is only ~25 GW — the queue is 7× peak load
• Svk notes most applications will not materialize, but the queue signals where demand is heading
• For output (consumption): dominated by industrial electrification, hydrogen, data centers

Demand scenarios (LMA2024)

Four long-term scenarios developed jointly with Energiföretagen and Ei:

Current (2023): ~135 TWh. All scenarios project significant growth, driven by EVs, heat pumps, industrial electrification, data centers, and potentially hydrogen production.

Bidding areas and the north-south imbalance

Sweden is divided into four Bidding Areas (SE1–SE4). The fundamental structural challenge:

• SE1–SE2 (north): Large surplus — hydropower and growing wind generation far exceed consumption
• SE3–SE4 (south): Deficit — most consumption, historically supplemented by nuclear (reduced after closures of Ringhals 1–2 and Oskarshamn 1–2)
• Transmission capacity from north to south is the binding constraint, creating price differences between areas

NordSyd initiative

The NordSyd initiative is Svk’s flagship program to increase north-south transmission capacity. Four parallel branches:

1. Uppsala branch — new double 400 kV lines through Uppsala/Västmanland
2. Västerås branch — new lines and substations through Västmanland
3. Karlstad branch — Borgvik–Malsjö new 400 kV line through Värmland
4. Hallsberg branch — Storfinnforsen–Bäsna–Hallsberg new double 400 kV lines (inland route)

Timeline: progressively through 2030s. Some branches in contracting phase, others under consideration.

Flow-based capacity calculation

Sweden (and the Nordics) transitioned from NTC (net transfer capacity) to Flow-Based Capacity Calculation in October 2024. This method:

• Calculates available cross-zonal capacity based on actual physical power flows (Kirchhoff’s laws)
• Is more accurate than NTC, which simplified flows to bilateral exchanges
• Can both increase and decrease available capacity depending on flow patterns
• Already used in Central Western Europe since 2015

Conditional connection agreements at TSO level

Section 4.4.2 describes Svk’s exploration of conditional connection agreements — conceptually similar to Villkorade Avtal at DSO level. Svk commissioned a feasibility study and found that “managing full-scale implementation proved to be impossible with the systems and tools available today.” This highlights the digital infrastructure gap even at TSO level. Svk continues to study the approach.

Hydrogen co-planning

Hydrogen production is modeled as a major future electricity consumer (87 TWh in the Hydrogen scenario). Svk coordinates with hydrogen infrastructure planning, recognizing that co-locating hydrogen production with generation can reduce transmission grid needs. Hydrogen pipelines can partly substitute for electricity transmission.

HVDC interconnections

Sweden’s cross-border connections (existing and planned):

The rejected Germany interconnector (Hansa PowerBridge) was terminated after government rejection in 2024.

Civil preparedness

The plan notes increasing importance of total defense considerations. Grid investments must account for resilience, redundancy, and the ability to maintain supply during crises. This is a newer dimension of grid planning alongside the energy transition.

Flexibility relevance

This source is critical context for understanding why Flexibility is needed and how it relates to grid development:

1. Grid expansion is slow and expensive (SEK 225 billion over 10 years, projects take 10–15 years). Flexibility bridges the gap.
2. The connection queue vastly exceeds grid capacity — conditional connections and flexibility are the only way to accommodate demand faster than the grid can be built.
3. Svk itself tried and failed to implement conditional connections at TSO level due to digital infrastructure gaps — highlighting the importance of the software/digital layer.
4. The north-south bottleneck drives both massive infrastructure investment (NordSyd) and the need for flexibility to manage congestion until that infrastructure is built.
5. Hydrogen co-planning introduces a new flexibility dimension: locating flexible hydrogen production where generation exists rather than transmitting electricity.