Grid development and maintenance

The power system is going through an unprecedented shift. Fingrid targets efficient electricity markets in the Baltic Sea Region to ensure power adequacy in all conditions. ‘The clean power system of the future’ requires a grid with powerful transmission connections in order to function in the best possible way.

When it comes to investing in the power system, timing is everything – Fingrid insists on carefully choosing the right time for grid updates and avoiding excessive investments. Fingrid’s effective tendering model guarantees the capability to expand the grid at a reasonable price. The company’s annual capital expenditure will be around EUR 100 million in the next few years. This will be sufficient to keep the grid in good repair, yet with no pressure to increase grid service prices.

Fingrid’s grid asset management lives up to any international standard. In spring, Fingrid placed at the top in the International Transmission Asset Management Study (ITAMS), as it has for several years now.

Our aim is to build the grid of the future. This often means a change in grid technology when replacing the existing power lines. Increasing digitalisation is an important aspect of our future. Fingrid is currently starting up its first digital substations, with focus on IoT (Internet of Things) technologies. IoT will bring changes to the existing substations as well.

Ongoing projects

A total of 22 substation projects and 16 power line projects or transmission line arrangements were under way in 2017.

The biggest current projects are related to the modernisation of the aging ‘Iron Lady’ transmission line, connecting large-scale power plants to the grid, and maintaining system security for major cities.

The modernisation of the ‘Iron Lady’, the oldest part of the national grid, from Forssa to Lieto and Yllikkälä to Koria, proceeded according to plan. The project is expected to be completed early in 2018. The modernisation of the Koria substation and the related projects are a part of the long-term grid development plan.

A new 400 + 110-kilovolt power line is under construction between the Hikiä substation located in Hausjärvi and the new Orimattila substation to be constructed in Pennala, Orimattila. The transmission line between Hikiä and Iso-Henna will be dismantled and replaced with a new power line. Work on the foundations of transmission line pylons was started in December 2017 and will be followed by the assembly and erection of pylons and conductor installations. The entire transmission line will be completed in December 2019.

Olkiluoto’s 400-kilovolt switching station, which is outdated and has insufficient system security, will be modernised in Eurajoki. The project will be completed during 2019. The modernisation of Inkoo’s 400-kilovolt substation has also been started and is due for completion in 2019.

Fingrid has built a new 110-kilovolt power line from Äänekoski to Laukaa. The newly completed Metsä Group bio-product mill at Äänekoski is producing more than double the electricity required for its own operations. A new power line was needed to supply the surplus electricity to the grid. The 26-kilometre Vihtavuori–Koivisto power line between Laukaa’s Vihtavuori and Äänekoski’s Koivisto substations was built parallel to an existing power line. The power line project and the required extensions in substations were completed in January 2018.

The expansion of the 400-kilovolt switching station of the Länsisalmi substation progressed on schedule. The Länsisalmi substation is in a key location in Vantaa, close to Helsinki, as a transmission hub between Fingrid’s grid system and the consumers of electricity in Helsinki and Vantaa. Due to increased consumption, Fingrid expanded the Länsisalmi substation to secure the supply of electricity throughout the capital region. The project was completed at the end of 2017.

A power transformer supplied to Fingrid was taken into use at the Espoo substation. The transformer will ensure sufficient transmission capacity in the Espoo region well into the future and facilitate grid operating situations in Southern Finland.

The commissioning of the upgraded Huutokoski reserve power plant was completed on schedule in November 2017. The Huutokoski reserve power plant upgrade project consisted of replacing outdated systems and improving the plant’s environmental safety. The challenging project included a total of 16 subcontracts and equipment deliveries as well as numerous separate service and component deliveries and dismantling jobs required to support the main project.

Investment decisions

Several new investments in grid maintenance and development were decided during 2017.

In late 2017, Fingrid made a decision on a grid upgrade in the North Karelia region, with plans including both new power lines and substations. A 36-kilometre section of power line falling into disuse will be dismantled and the right-of-way will again become available for agriculture and forestry. The production and consumption sites are far apart in North Karelia, often resulting in long transmission distances. A powerful and reliable grid will serve both Fingrid’s customers and consequently all electricity users in the region.

The total investment costs for all the related projects, to be located north of Joensuu, will amount to nearly EUR 32 million. This investment decision by Fingrid entails an extensive set of rebuild projects on three power lines built mostly in the 1960s. The total length of the power lines, located north of Joensuu, in the municipalities of Joensuu and Kontiolahti, is approximately 112 kilometres. The implementation will take place within several projects, with a final deadline for completion in 2021.

The investment decisions of 2017 furthermore included the rebuilds of four obsolete substations. The substations, located in Uusikaupunki, Oulu, Jyväskylä and Kajaani, will be modernised to improve the system security of the respective regions. The projects will be completed during 2019.


Maintenance operations are becoming increasingly proactive and digitalised. It has always been a critical priority for Fingrid to carry out any maintenance work with minimal disturbance to the grid service. New digital solutions help keep costs in check and outages short, and in the best case, even completely eliminate them. The goal is to avoid maintenance-related outages altogether.

In 2017, Fingrid carried out a competitive tender process for the basic maintenance on substations and power lines, as well as basic and special maintenance on secondary equipment. The new three-year contractual periods start at the end of 2018 and expire at the end of 2020.

Future grid – planned investments

The bulk of electricity consumption in Finland takes place in the south of the country, where demand will exceed the production capacity even after the Olkiluoto 3 power plant is completed. Electricity produced in northern Finland and northern Sweden must be transferred to the south to serve the needs of industry and consumers. Strong transmission connections are required between the north and the south. Inadequate transmission capacity may in the future make it necessary to divide Finland into two price regions.

Growing wind and nuclear power production will further increase the surplus of electricity generated in the north of Finland, particularly on days with heavy winds in the north. According to current estimates, approximately 2,800 megawatts of new wind power capacity will be built in Finland by 2025, of which roughly 1,900 megawatts essentially in the northern parts of the west coast. The Fennovoima nuclear power plant project, rated at 1,200 megawatts, is also located north of the P1 section line critical for the transmission of electricity.

Sweden is the biggest producer of wind power in the Nordics. A substantial part of the Swedish wind power comes from the north of Sweden, from where it must be transmitted to the south. Thanks to the new transmission link between Finland and Sweden, to be completed in 2025, more Swedish wind power will become available in Finland.

Fingrid aims to ensure sufficient transmission capacity with four strong 400-kilovolt north-south transmission lines. The plans furthermore include an AC link from Sweden to Finland and the Kvarken DC link from the Vaasa region to Sweden. The planned transmission links will support a controlled and safe transition to a clean power system.

Investment projects of hundreds of millions of euros

  • New overland (“Forest Line”), 400 kV, from Oulu to Petäjävesi. Expected completion in 2022, EUR 85 million
  • Third AC link between Sweden and Finland at the latest in 2025, EUR 200 million
  • New marine (Kvarken) DC link from Vaasa region to Sweden. Expected completion by the end of the 2020s, around EUR 350–410 million


Planning of the transmission line between Oulu and Petäjävesi, named “Forest Line”, has begun and construction work will be started within a couple of years. The connection will be roughly 300 kilometres long and will have a transmission capacity of approximately 700 megawatts. The cost of the investment is estimated at EUR 85 million. The employment impact of the project amounts to around 500 man-years.

A third 400-kilovolt AC link will be built between Finland and Sweden at the latest in 2025. This is a joint project between Fingrid and the Swedish transmission system operator Svenska Kraftnät. The EUR-200-million connection has been included in the EU’s list of energy infrastructure priority projects and the European Commission has granted it PCI (Projects of Common Interest) status. Such status is granted to projects that are essential to the EU’s internal energy markets and to achieving the targets of the EU’s energy policies: secure, cost-competitive, and sustainable energy.

The new connection will increase the transmission capacity between the two countries by 800 megawatts.  Fingrid initiated during the year under review an environmental impact assessment (EIA) for the Pyhänselkä–Keminmaa power line project. The transmission connection to Sweden also requires strengthening Finland’s internal connections, including the Forest Line to be built between Oulu and Petäjävesi.

The Finnish and Swedish TSOs have started synchronised planning of the new Kvarken DC link. The plans envisage a new, roughly 800-megawatt connection to be built by the end of the 2020s. The Kvarken connection would replace the Fenno-Skan 1 DC connection, which is reaching the end of its service life. In Finland, the starting point for the new link would be in the Vaasa region. The new transmission connections would benefit the markets of the entire Baltic Sea Region and enable a transformation of the power system, including a major increase in renewable electricity generation.

Occupational safety

Corporate safety is a key part of Fingrid’s operations, steered by the company’s safety policy. The occupational safety management of Fingrid’s asset management function and suppliers is steered by the safety management system and contractual terms concerning safety. These were updated in 2017 as part of the company’s continuous development efforts. In addition to the above, Fingrid has created an extensive new development programme in order to learn from hazardous situations and prevent similar incidents from reoccurring.  

The contractual conditions related to safety were updated. A safety culture survey was arranged for service suppliers and Fingrid’s personnel an occupational safety group was established for service suppliers, and the group started its activities by planning future targets. In addition, efforts were made to improve the supplier selection, and the work to develop a mobile reporting system for occupational safety, quality and environmental issues and safety management system continued. Due to a fatal accident, an extensive development programme was drawn up to prevent similar incidents, and more severe sanctions were imposed on safety deviations.

Fingrid’s own personnel had two lost-time accidents (0). Suppliers had 9 (12) recordable incidents, one of which was fatal and eight were lost-time accidents. Among the lost-time accidents, two led to an absence of more than 30 days from work. The suppliers’ and Fingrid’s combined accident frequency rate remained unchanged, at 8 (8). Based on the investigation of the fatal accident, a programme for immediate corrective measures was drawn up in co-operation with the supplier. Fingrid drew up an extensive development programme to prevent any similar accidents from happening in future. The development programme focuses, for example, on increased supervision, more rigorous sanctions, instructional videos as well as developing the structural safety and guidelines on work at heights.  

Key events of 2017

Fingrid names main transmission lines in commemoration of Finland’s centenary

Pylon erection demo in Hämeenlinna

Blue and white light in the fence of the Tammisto substation

In June, Fingrid published a draft of its grid development plan for 2017–2027