The importance of investments in the electricity grid

At the end of December, Vaasan Sähköverkko prepared for power outages caused by the forecasted storm by reserving additional resources for fault servicing, limiting outage areas, clearing and repairs. The destruction caused by the storm was extensive in large parts of Finland. It would have been significantly worse without the high percentage of underground cables in the power grid. Underground cables are one way to prevent storm damage, but other measures are also needed.

The law requires shorter power outages

The Electricity Market Act requires that power outages be shortened, i.e. that the security of energy supply be improved.

This amendment to the law has been the main reason why large parts of the electricity network have been buried in many parts of Finland.

Vaasan Sähköverkko has been laying underground cables for a long time.

Currently, 55 percent of the medium-voltage network and 76 percent of the low-voltage network are in the ground.

CEO Jarmo Leppinen says that the work continues, the goal has not yet been reached.

In a two-year project, which started in 2025, a line between Vallvik and Vassor in Korsholm (Mustasaari) is being laid in the ground. But the largest cabling projects are done. For example, in 2021, a total of 200 km of cables were laid in the Vaasan Sähköverkko distribution area.

Leppinen dares to estimate that the damage caused by Christmas holiday storm would have been significantly greater without the measures taken.

Not only cables

The proportion of the network that is underground is of great importance from a storm damage point of view. Every year, Vaasan Sähköverkko invests in increasing the degree of underground cables.

However, it is not possible, nor is it worthwhile, to bury the entire network in the ground. New overhead lines are also being built, and there is a clear reason for this:

– By law, the distribution security of the electricity network must be developed with measures that provide the lowest possible life cycle costs, reminds Development Manager Ari Salo from Vaasan Sähköverkko.

How many faults occur in the electricity grid during storms, and how difficult they are to fix, depends on many things.

Every storm is different. The direction of the wind, the strength of the gusts, the season and whether the ground has become frost-bound or not have an effect.

– The number of repair sites does not only depend on how much of the grid is underground. Also, the location of overhead lines, whether forest management is carried out in edge zones and the types of transformers used affect the scale of damage.

– How quickly everything can be repaired is also affected not only by the resources available, but also by the location of the broken lines and the materials used in poles and wires, just to name a few examples, Salo lists.

An important measure to reduce storm damage is to move overhead lines to the roadsides. At the roadside, lines are easier to maintain and security of energy supply is improved.

Another important measure is the clearing of adjacent forests. This is done in collaboration with landowners.

In recent years, a lot of automation has been added to the power grid.

Automation helps to identify faults, limit the extent of power outages, and predict, shorten and prevent fault situations.

There is a cost to developing the electricity grid

The development of the electricity grid cannot be carried out without major investments.

Over the past five years, Vaasan Sähköverkko has invested approximately EUR 70 million in, among other things, the above-mentioned development measures.

– Cost-effectiveness comes from the law and is otherwise also an important value, says Jarmo Leppinen.

Despite this, the pricing and rising costs of electricity distribution have been loudly criticized for years. So much so that the supervisory authority has tightened the upper limit for reasonable returns.

– Despite this, it is important to find the right balance between development and cost savings.

– Without sufficient returns, there is no opportunity to invest where it is needed.

The development of society, the increase of renewable energy, the electrification of transport and heating, as well as extreme weather phenomena require increasing investments in the electricity grid. In other words, measures taken to develop the electricity grid are a prerequisite for many other things to be developed, for competitiveness, but also for a secure society.