Grid ownership
Transmission network: a technically and operationally connected network with a voltage of 220 kilovolts or more that stretches across several grid regions in Sweden and links the national electricity network with electricity grids in other countries.
Transmission network company: a network company that owns a line that is part of a transmission network (Electricity Act). Svenska kraftnät is the network owner for Sweden's transmission network (according to Svenska kraftnät’s webpage).
Regional network: a line or a network of lines that is not part of a transmission network and which is covered by a network concession for a line or for an area with a minimum permitted voltage. Local network: a network covered by a network concession for an area without a minimum permitted voltage. Distribution network company: a network company that owns a local network or a regional network (Electricity Act).
Island interconnection
The legislation does not distinguish islands from the mainland. Islands, facilities on islands, and customers on islands may obtain a connection to the grid. Upon such a request, the DSO is obligated to establish a connection. In some cases, private islands have been given the right to run their own grid with their own generators.
Island TSOs and DSOs
The legislation does not distinguish islands from the mainland. According to Energy Market Inspectorate’s report Ei R2022:11 Security of supply in Sweden's electricity grid 2021, Svenska kraftnät is the only TSO in Sweden.
Development of electricity grids for RES integration
Svenska kraftnät shall, among others, within its area of operation, ensure that the opportunities to expand fossil-free electricity production and new areas of use for electricity are taken advantage of in the conversion of the electricity system. Also, within its area of operation, Svenska kraftnät works to ensure that the energy policy goals approved by the Parliament are achieved. Svenska kraftnät has previously worked on the expansion of the transmission network to areas within Sweden's territorial waters where there are conditions for connecting several electricity production facilities and where such an expansion promotes the fulfilment of Sweden's goals for renewable electricity production. But according to the Amendment to the regulation (2007:1119) with instructions from the Swedish Power Grid Agency, Svenska kraftnät will no longer specifically be tasked with expanding the transmission network to areas within Sweden's territorial waters. The principle that whoever connects to the electricity grid must be responsible for the costs caused by the connection must also be maintained at sea. Ordinance amending the Ordinance (2007:1119) with instructions for the Affärsverket Svenska kraftnät was issued on the 12th of October 2023.
Specifications for islands, isolated grids, microgrids, local grids, etc.
There are regulations on island operation from Svenska kraftnät. Island operation is a preparedness measure and means operation of production facilities, stations and electrical network in subsystems to supply an area or a business with electric power (The Swedish Power Agency's regulations and general advice on electricity preparedness).
According to Svenska kraftnät ’s booklet: Island operation, to ensure electricity supply in crisis situations, island operation means that electricity production facilities together with electricity users are operated in a geographically demarcated electrical network, without connection to the surrounding network. This is achieved by disconnecting it from the national transmission grid and instead balancing electricity production and electricity consumption entirely within the so-called island network. A basic prerequisite for island operation is that there is at least one local production facility. Island operation is used in crisis situations when extensive disruptions and network breakdowns.