Sähköt poikki – mitä sitten tapahtuu?

A power cut – what happens next?

A power cut – what happens next?

The control centre monitors the network 24/7, making sure that everyone gets their electricity. But how many Caruna employees are needed to restore power?

On Boxing Day seven years ago, control centre staff could not believe their eyes. A storm had paralysed a large part of the electricity network, and nearly 220,000 homes were left without electricity. This resulted in an intense operation involving a total of about one thousand people in different duties and roles.

There were some 750 electricity network fitters and forestry workers involved in repairing the networks, clearing trees from power lines and restoring power. This major disruption to the electricity network was managed by a major disruption management team. The repair operation was directed from the control centre, which was responsible for changing the connections in the electricity network and securing the occupational safety of field personnel.

Electricity network is cared for 24/7

The employees of the control centre monitor the network 24/7, making sure that everyone gets their electricity. A high wall is covered with data-filled monitors that display weather forecasts and information about the states of the network and substations. At a steady pace, the screens show current maintenance tasks and temporary interruptions, which are communicated to customers in advance by SMS.

When a customer reports a power cut to the fault service, a red alarm row appears on the control centre monitor and immediate action is taken to resolve the fault. There is no shortage of work at the control centre – up to 1.5 million rows are displayed per year.

Typical reasons for power cuts include burned fuses, fallen trees or cable damage caused by excavation work. When a fault emerges, a fitter goes to the site to examine it. If the fault is on a pylon or another hazardous location, the control centre will send out more people to assist the fitter. Safety is never compromised.

Puu kaatuneena sähkölinjalla
A fallen tree on an electric line.

Weather forecasts determine the number of people needed on duty

The weather map shows stable weather for the weekend, no exceptions. The control centre communicates weekly with a meteorologist at the Finnish Meteorological Institute. If the meteorologist predicts a storm, the impact of the storm is discussed, that is, the intensity of the storm and the area where it will likely hit.

The forecast is used to estimate the number of customers without electricity in the storm area and the likely damage to the network. After that, an appropriate number of electricians and equipment will be reserved, and the number of employees at the control centre, customer service and fault reporting service will be increased. Helicopters are used in larger disruptions, as they speed up fault detection. Hidden faults are also more easily detected from the air.

The Boxing Day storm was already forecasted before Christmas, and hundreds of fitters were on stand-by for the days between Christmas and New Year. When the extent of the damage was revealed, the number of fitters was doubled and, by the next day, it was possible to restore electricity to 100,000 customers.

Effective communication and nerves of steel

When a storm like the one that hit Finland on Boxing Day rages in the network area, red rows keep appearing on the screen at the control centre. The size of the workforce may be increased up to tenfold in an instant. Clear communication is important for the coordination of daily connections, but a massive operation takes communication to a whole new level. When fault reports are flooding into the control centre, employees need patience and nerves of steel.

The operators are calm and professional individuals who are able to react appropriately in every situation. Power can be safely restored – whatever the situation may be.

Read more