A capacity map can help narrow a search for a battery storage site in Switzerland. It cannot reserve capacity, establish a connection right or show the complete operating case for a battery. The distinction is especially important because the maps separate feed-in from feed-out, but their generic flexibility bands do not yet model a battery’s storage capacity or operating constraints.
Swissgrid’s connection-capacity maps, dated 1 June 2026, show indicative capacity at transmission-grid substations for both feed-out (load) and feed-in (generation). They cover the current grid and planned grid horizons for 2030, 2035 and 2040, with different flexibility assumptions. The methodology uses hourly market simulations and grid calculations, including the N-1 security principle, then deducts existing, allocated and reserved capacity at each node.[1, 2]
For a BESS, the first practical step is to inspect both directions. Charging is a grid load; discharging is a feed-in. A promising value on only one side does not show that the project’s requested import and export envelope can both be accommodated at the same location.
The available connection capacities are currently evaluated … without taking into account the storage capacity, flexibility or constraints of the plant.
The qualification matters: the maps already include generic cases in which a new connection can modulate power during grid overloads. Those cases are not a battery-specific dispatch model. Swissgrid lists consideration of flexibility associated with battery storage capacity and of services such as imbalance energy or redispatch as planned further developments—not features to assume in today’s figures.[2]
The methodology presents a base value and flexibility cases. In the flexible cases, a project must be able to modulate its feed-in or feed-out during grid overloads; the reported values represent capacity available for 90% or 80% of the time, depending on the flexibility assumption. This is not an unconditional capacity entitlement. It describes a different operating envelope that a project would need to demonstrate and agree.[2]
| Map element | What it tells you | What it does not establish |
|---|---|---|
| Feed-out / load | Indicative ability to draw power at the transmission node. | A firm charging right or the BESS’s permissible operating schedule. |
| Feed-in / generation | Indicative ability to inject power at the node. | A firm export limit for a specific connection application. |
| Flexibility case | Capacity associated with defined ability to reduce or modulate power in constrained periods. | That the project’s EMS, dispatch plan or contract can meet that condition. |
| Future horizon | Modelled capacity with planned grid developments assumed for that horizon. | A guaranteed connection date or assurance that approvals and network works will occur on schedule. |
Swissgrid’s model generally assumes all grid elements are in operation; outages can reduce capacity. It also does not include simultaneous applications at neighbouring nodes, and the indicative substation-feasibility estimate concerns substation modifications—not the connection line or a new substation. Those caveats make local competition and site-specific engineering essential.[2]
These maps cover Swissgrid’s transmission network, not every Swiss distribution network. Swissgrid’s published connection guidance states minimum connection capacities, for feed-in or feed-out, of 150 MVA at 220 kV and 300 MVA at 380 kV for direct transmission connections; for connection capacities below 150 MVA, the local distribution system operator is responsible and should be contacted directly. These are MVA thresholds in Swissgrid’s guidance—not a blanket MW rule for every battery. Confirm the applicable connection point, voltage level and responsible operator before using a transmission map to rank sites.[1]
For direct transmission connections, Swissgrid lists technical requirements for converter-based energy storage systems. Its general connection guidance also says that, based on current experience, commissioning a connection takes between three and ten years after receipt of the application, depending on land, authorisations, equipment lead times and implementation capacity. Since 1 June 2026, new transmission-grid connection applications for large batteries are subject to a non-refundable flat-rate application fee; Swissgrid says an application is only considered received when the fee is paid and the required information is complete.[1, 3]
A disciplined first review therefore records the requested import and export power separately, the relevant network level, map horizon and flexibility case, the site and connection-line constraints, and the open questions for the responsible operator. Then validate those points through the formal process; a map marker is not a substitute for a connection assessment.
Use the map to decide what to investigate next—not to declare a Swiss BESS site connected, available or feasible.
For the related cost question, see our analysis of Swiss BESS grid-connection contributions. Our Swiss BESS development overview explains why connection feasibility and permitting must be checked together.
Checked on 10 October 2026. The technical statements below follow Swissgrid’s published connection guidance and methodology. The site-review questions and their development implications are CurvatureEnergy’s analysis.
without taking into account the storage capacity, flexibility or constraints of the plant.Illustration: CurvatureEnergy schematic. It is not a Swissgrid capacity map and contains no connection-capacity data.