Source - Förstudie Krisberedskap och ö-drift Skåne (2023)

Energikontor Syd, August 2023 — Krisberedskap och ö-drift: Förstudie i Skåne län 2023. Author: Karoline Alvånger; Editor: Johanna Wallin; Quality review: Pierre Ståhl. Funded by Region Skåne. ~37 pages.

Feasibility study mapping Skåne’s potential for intentional ö-drift for crisis preparedness. Conducted via stakeholder interviews, a webinar, and literature review.

Summary

Skåne (elområde SE4) has very low self-sufficiency in electricity production (~15% in 2023) and is heavily dependent on imports from SE3 and cross-border connections. The study maps whether existing generation sources in the region could support island operation to supply critical infrastructure (samhällsviktig verksamhet) during extended grid outages.

Main finding: No suitable object could be identified for further detailed investigation. This is based primarily on technical challenges in existing installations, and also on stakeholders’ assessments that other preparedness approaches (diesel generators, batteries) may be more cost-effective. However, the study notes these assessments are based on assumptions rather than detailed cost analysis.

Kartläggning (survey)

Production sources capable of supporting island operation (> 1 MW electrical output per installation):

Most waterpower plants are in northern Skåne, far from population centres. CHP plants are the only practical option — but face major technical barriers (see below).

June 2023 development: Svenska kraftnät decided to preserve Öresundsverket (Malmö) for island operation readiness by 2025. This significantly changes Malmö’s situation; Öresundsverket’s output nearly covers the total power need of the Malmö-Burlöv grid area.

Technical challenges: generation types

CHP plants

• Most lack cooling capacity (kyltorn or nearby water); heat must be consumed. In a grid outage, fjärrvärme customers outside the island network lose their circulation pumps, reducing heat demand — and thereby limiting electricity output
• Cooling towers are expensive and require environmental permits
• Control flexibility is limited for solid-fuel boilers — quick load-following in an island network is technically demanding
• Plant internal electricity consumption requires a share of output for fjärrvärme pumps, control systems, and burner feeds
• Revision schedules (typically summer) conflict with preparedness readiness requirements
• Husturbindrift: allows controlled transition to self-consumption at grid fault; provides fast restart capability — not available at all CHP plants

Vattenkraft

• Good regulation capability and no fuel logistics requirement
• Most Skåne plants are either very small or remote from population centres
• Seasonal flow variation affects available output — must be included in planning

Reservaggregat (conventional diesel)

• Proven technology; already present at many critical facilities
• Limited capacity; fossil fuel dependency; not designed for extended operation
• As EV electrification increases, reserve generators must scale with it

Energilager (batteries, vätgas, pumpkraft)

• Batteries: fast regulation; limited energy duration; require complementary generation
• Vätgas: good energy density; costs still high (2023); future option especially with weather-dependent production
• Pumpkraft: conceptually viable; largely untested in Sweden; requires large infrastructure investment

Gasturbiner

• Fast start-up; well suited for reserve power
• Expensive acquisition cost; must be paired with bio/vätgas fuel source for fossil-free operation
• Recommended by the report as a future option if placed at bio- or vätgas production sites

Technical requirements for island operation

Two phenomena that arise when grid connection is lost:

1. Low svängmassa (inertia): rotation energy that smooths load variations is reduced; frequency is more sensitive to sudden production/consumption changes
2. Low kortslutningseffekt: fault currents are lower; protection relay settings may need adjustment for reliable trip selectivity

Requirements for stable island operation:

• At least one source capable of reglering av spänning och frekvens
• Dödnätsstart capability (starting from a dead grid, usually via battery or diesel for auxiliary systems)
• Controlled load connection; no simultaneous switching of large loads
• Fjärrmanöver (remote switching) highly beneficial for reducing DSO staff workload

Organizational structure for ö-drift leadership

Roles in the ö-driftledning:

• Ö-driftledare: usually from the dominant DSO; leads grid build-up and operation
• Produktionssamordnare (el): coordinates electricity production; monitors available power
• Balansansvarig: monitors power balance; keeps frequency within acceptable limits
• Kopplingsansvarig: manages grid switching
• Fjärrvärmeansvarig: coordinates heat production and distribution
• Informations- och kommunal samordnare: interface to municipal leadership and media

Financing options

1. Elberedskapsanslag (Svenska kraftnät)

Svenska kraftnät can allocate preparedness funds (elberedskapsanslag) for:

• Feasibility studies
• Capital investment to achieve ö-driftförmåga

2. Ancillary services (stödtjänster)

CHP plants that improve their controllability for ö-drift may also qualify to offer ancillary services on Svk markets, generating revenue during normal operation. Participation feasibility depends on:

• Available cooling (enables operation regardless of heat demand)
• Modern automatic turbine control (ramp-up speed)
• Larger plants and affiliated organizations (pricing/IT tools)

CHP plants face difficulty offering FFR and FCR-D (fast activation), but can participate in FCR-N and mFRR if ramp-up and minimum bid (10 MW for mFRR, 5 MW in SE4) can be met.

Stödtjänst overview (as of April 2023):

Hydropower dominates FCR/aFRR volumes. BESS is rapidly growing and pricing CHP out of faster markets.

Swedish island operation examples

Ludvika (realized, operational)

Study conducted 2006–2007; implementation followed. Based on hydropower (3.5 MW) + 400 kWh battery (300 kWh reserved for crisis) + 218 kW solar.

• Battery enables dödnätsstart of the hydro plant after national grid failure
• Hydro then takes over voltage/frequency regulation and powers expanded priority loads (water treatment, fuel stations, heating plant)
• Investment: ~6 MSEK excl. solar, half from Energimyndigheten

Simris (completed, not continued)

EU Horizon 2020 project by E.ON; wind (500 kW) + solar (440 kW) + backup generator (480 kW, HVO diesel) + lithium-ion battery (800 kW, 0.33 MWh) + flow battery (200 kW, 1.05 MWh). Normal load: 800 kW.

Battery provided voltage/frequency regulation during island mode. Project completed; equipment to be dismantled (as of 2023). Required ongoing software maintenance even after installation.

Skälleryd (Mönsterås)

Run-of-river hydro (1200 kVA). No upstream reservoir; highly seasonal. Proposed modifications include a dump load (100 kW) for frequency regulation and battery storage (400 kWh). Neither modification implemented; island operation not yet possible as of 2023.

Jönköping (planned)

Biomass-fired CHP + hydropower backup. Modifications needed: dödnätsstart capability, cooling at bio boiler, communications system. Planned completion: end of 2024. Municipal plan: 7-day capability; expects day-1 unavailability.

Conclusions

1. No suitable Skåne object found — based on technical constraints and stakeholder assessments of alternatives
2. CHP plants are the only planerable sources in urban Skåne, but most lack cooling and have limited load-following capability
3. For geographically dispersed priority loads, conventional diesel generators or batteries may be more cost-effective per-kW of preparedness capacity achieved
4. Öresundsverket (decision June 2023) changes Malmö’s situation fundamentally — a large gas turbine plant available for island operation by 2025
5. Future options: new gasturbiner at bio- or vätgas production sites; converted värmeverk; decentralized battery+gas turbine combinations for smaller load clusters
6. V2G / EVs at an island network access point could supply remote priority loads that cannot be connected to the island grid

Relevance to other wiki pages

• Island Operation — technical requirements, Swedish examples, CHP challenges, financing via elberedskapsanslag
• Energy Storage — battery role in dödnätsstart; Ludvika case; BESS competing with CHP on ancillary markets
• Electric Power Distribution — DSO role in ö-driftledning; network reconfiguration requirements; low kortslutningseffekt in island networks

Data gaps

See Island Operation › Data gaps for the canonical tracking of Jönköping and Öresundsverket implementation status.