In Estonia, there are currently no specific support systems exclusively designated for renewable energy production on islands.
The Ministry of Climate is supporting Estonia's largest islands, Saaremaa, Hiiumaa and Muhu, by allocating €13.7 million to DSO Elektrilevi for the construction of a weather-resistant electricity grid. A new underwater cable is also being installed between Saaremaa and Hiiumaa to enhance the reliability of the electricity supply and increase network capacity, expected to be completed by the end of 2025.
Grid ownership
Estonia's state-owned TSO Elering manages the Estonian electricity and gas system, according to the Electricity Market Act. It is responsible for the functioning of the Estonian electricity system. However, the government can take measures with regard to all market participants to maintain the security of supply in case something endangers it, according to Electricity Market Act.
Island interconnection
With over 2200 islands in Estonia, only 22 are permanently inhabited. The list of these islands is provided by Statistics Estonia. Three islands (Saaremaa, Hiiumaa and Muhu) are considered “large islands” according to the Small Islands Act.
“Permanently inhabited small islands” are defined as islands with an area below 100 km2 and with a population of at least five inhabitants. They have certain special conditions stipulated by the law. Saaremaa and Hiiumaa are regional authorities (counties), but the responsibility for the connection to the electricity grid lies with the TSO in either case. Large islands are connected to the electricity grid, but not all of the small ones are. There isn't a thorough overview of the detailed situation in terms of electricity connections on small islands.
Every case is different:
Abruka, an island with an area of 8,8 km², has an undersea power cable connected to Saaremaa, according to an analysis published by the Association of Estonian Islands. Kesselaid, Pakri Saared doesn't have any electricity connection, the analysis brings out.
Ruhnu, with an area of 11.9 km², has its own autonomous power plant that covers local needs. The power plant operates on a combination of diesel heating and solar and wind energy.
In the Small Islands Act, the following definitions are used:
Island rural municipality is a rural municipality which administers a permanently inhabited small island or an archipelago as a whole;
A local authority which includes small islands is a local authority which comprises permanently inhabited small islands, but is not part of island rural municipalities;
Permanently inhabited small islands are islands with an area below 100 km2 and with a population of at least five inhabitants;
Large islands are Saaremaa, Hiiumaa and Muhu.
Permanent inhabitation is permanent and predominant residing on a small island.
Island TSOs and DSOs
Elering is the only TSO in Estonia.
As of the end of 2023, according to the Competition Agency, there were 33
DSOs in Estonia. The biggest is Elektrilevi, operating in the biggest islands, Saaremaa, Hiiumaa, and Muhu. It also covers two islands, Ruhnu ja Prangli, separate from the main system. Renewable energy company Enefit Green manages the solar power plant on Ruhnu island.
What does the legislation say about the development of electricity grids for RES integration?
The Electricity Market Act and Grid Code stipulate simplified connection conditions for electricity-generating installations that use renewable energy sources and have a capacity below 15 kW.
Specifications for islands, isolated grids, microgrids, local grids, etc.
There are no exceptions for the islands specifically. The Electricity Market Act describes “micro isolated networks” as a network located in a service area without an electrical connection where the consumption was less than 1 gigawatt-hour in 1996. In the micro-isolated network, the services are provided by the DSO that ensures the security of supply and the balance of that network.
The network operator in whose service area the micro isolated network is located ensures the security of supply and the balance of that network in accordance with this Act and the grid code.
In the permanently inhabited small islands, the local governments and the state ensure the availability of electricity supply and transport connections.
The objectives of the state and local governments in the administration of the permanently inhabited small islands include:
- restoration, preservation and supporting the development potential of permanent inhabitation;
- supporting the local government capacity and increasing the participatory democracy;
- creating workplaces and subsistence opportunities for permanent inhabitants and supporting enterprise; ensuring the availability of vital public services (police authorities and rescue service agencies, drinking water, postal services and electronic communications, electricity supply, transport connection, pre-school, basic and secondary education, and social assistance).