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The main grid can handle many weather phenomena

Although storm winds, lightning, crown snow load, frost and freezing rain pose a threat to power lines, Fingrid is well prepared for problem situations caused by the weather.

The Finnish Meteorological Institute and Fingrid collaborate in a diverse manner. Fingrid particularly needs observation and forecast information about the wind, lightning, crown snow load and frost.

“Storm winds are a climate threat to the main grid even though they rarely cause disturbances. Fingrid raises its preparedness whenever storm winds continuously exceed 20 m/s in a land area. Proactive work also begins when the crown snow load accumulates on a transmission line structure. We start patrolling on the ground and in the air to monitor transmission lines and dislodge any crown snow load that has built up on the structure,” says Fingrid’s Control Room Manager Arto Pahkin.

Tree-proof transmission lines are one way of preparing for crown snow load and ice loads in advance.

“We clear the main grid right-of-way every eight years, and there is also a ten-metre border zone on both sides where the trees cannot be too high. This means that falling trees don’t land on electricity lines and interfere with grid operations. Along with storm winds and crown snow load, lightning causes problems and we use a lightning radar system to monitor the movements of thunderstorms,” explains Pahkin.

Fingrid always has access to up-to-date weather information provided by the Finnish Meteorological Institute via the Ilmanet service. The Meteorological Institute also produces a weekly weather review presented by a meteorologist in the Krivat system, which provides the opportunity to ask more detailed questions about the weather situation. The Meteorological Institute communicates about issues affecting critical infrastructure by means of Luova bulletins, a system that takes its Finnish name from preparation for natural hazards.

“The meteorologist compiles a Luova bulletin when a weather situation is expected to have significant effects on, for example, electricity distribution. A Luova bulletin contains a forecast of the strength, movement and area affected by the weather phenomenon. It also assesses the impact of the phenomenon and is updated when necessary. A second preparedness product called Luova monitoring is drawn up on a daily basis. This forecasts the probability of weather phenomena that will be hazardous to society and covers a period of approximately one week,” says Marja Aarnio-Frisk, Head of Group at the Finnish Meteorological Institute.

The timing of a reliable forecast depends on the phenomenon

Temperature can be reliably forecast about 7 days in advance, the routes of precipitation fronts 3–5 days in advance, low pressure and winds 2–3 days in advance, and thunderstorms and amounts of precipitation 0–2 days in advance.

“Tornadoes, downbursts and major thunderstorms are especially difficult to forecast and locate in advance,” states Aarnio-Frisk.

During the winter, it’s hard to forecast whether rain is freezing and how much snow will accumulate.

“We’ve cooperated with the Finnish Meteorological Institute to, for example, improve our ability to forecast and locate crown snow loads accumulating on the lines. We have also researched the effects of freezing rain on electricity lines,” says Pahkin.

Increases in readiness are always planned

An increase in readiness is associated with a forecast or event that makes it necessary to reserve company or service provider employees to manage disturbances or repair faults. Examples of such events include the threat of a serious disturbance in the main grid, loss of part of the operation control system or some ICT connections, or a forecast of a significant climate threat.

“If necessary, we establish a crisis centre in conjunction with the control room to efficiently handle external and internal communications regarding the disturbance. Properly timed communication with stakeholders, the authorities and media is important,” explains Pahkin.

The Electricity Market Act requires grid companies to draw up a preparedness plan. Fingrid’s preparedness plan brings together Fingrid’s guidelines concerning preparedness and disturbance management and information about preparedness. The preparedness plan contains a readiness section that provides regulations for Fingrid’s actions in extreme conditions.

“The plan forecasts threats and minimises disturbances,” assures Pahkin.


KRIVAT – a preparedness system for critical infrastructure

  • Developed by the National Emergency Supply Agency and maintained by State Security Networks Group, this system is intended to help society make a faster recovery from serious disturbances.
  • Information about the disturbances and maintenance work of various operators and the duration of them is produced for the system on, for example, a map template.
  • Krivat is a tool that allows companies and authorities that are critical to the functioning of society to communicate in real-time, agree on actions and allocate resources during disturbance situations.
  • Accurate information speeds up decision-making and helps optimise the use of expert resources. This allows society to recover faster and reduces damage.
  • Fingrid utilises Krivat to form a general picture of the situation, for communication purposes, and to disseminate information.

Elenia uses cabling to safeguard electricity distribution

By 2028, the distribution grid must be constructed so that damage caused by a storm or snow load does not interrupt electricity distribution for more than six hours in a town planning area. Interruptions in rural areas may be no longer than 36 hours. This is stated in the Electricity Market Act that took effect in 2013.

Every distribution grid company has to decide how to safeguard their own services. Elenia’s solution involves using underground cabling in its electricity grid. The company’s 417,000 private, corporate and society customers are located in Kanta-Häme and Päijät-Häme, Pirkanmaa, Central Finland and Ostrobothnia.

“We’re installing underground cabling at a pace that will make 2,500 kilometres of distribution grid weather-proof each year. At this time, underground cabling has been completed on more than 35% of our grid, and we would like to reach 70% by 2028. We’ve used only underground cables on our electricity grid since 2009 because our research shows that it is the most reliable and best solution for the future needs of society. We’ve already invested more than 115 million euros in a weather-proof electricity grid this year,” says Elenia’s Head of Communications Heini Kuusela-Opas.

The communications is systematic about disturbances in electricity distribution.

“Communications is an integral part of our preparedness system. Our control room is always manned and we check our personnel, contractor and material resources whenever we receive a cautionary Luova forecast. During major disturbances in electricity distribution, we hold systematic situational reviews every few hours. All responsible persons, including our contractors, participate in these events. We edit the memo from every review to produce a situation bulletin that is used by customer service when dealing with fault reports, on our website and in social media. If necessary, we send the bulletin to the media as part of our round-the-clock service. We also maintain contact with municipalities, rescue authorities and officials,” explains Kuusela-Opas.

The basic messages in a crisis situation are: What has happened and why? When will the situation be normalised and how?

“People get irritated when information is not available. Once they receive information, people can actually affect the situation,” says Kuusela-Opas in conclusion.