Security of energy supply

Our most important task is to supply energy and heat to our customers in a reliable way – around the clock throughout the year.

The objective is that our customers experience a power cut on average only once every five years at the most (SAIFI 0.2 outages/a). In the event of a power cut, it will last an average of half an hour at the most (CAIDI, min/outage).

In addition, the average duration of the interruptions (SAIDI, min/a) is at least among three of the most highly rated urban electricity network companies.

The indicators describing a power cut are calculated by using all interruptions (also planned ones) and all voltage levels, with the exception of disturbances caused by the national grid and other feeding networks. However, the design criteria for a 110-kV network are prepared for the fact that one missing feed of the national grid will not cause a supply interruption for customers.

In 2021, the indicators describing power cuts were at a good level. The average outage duration (SAIDI) was 4.2 minutes, the average number of outages (SAIFI) was 0.12 and the average outage duration (CAIDI) was 35 minutes.

Reliable supply of heat energy is at a good level in sector comparison. Our aim is to keep supply disruptions caused by faults and damage in the heating season permanently below 0.8h per resident per year.

In 2021, this target was met: the outage time caused by faults and damage was 0.45 hours per customer.

In order to improve the security of supply, we allocate a significant amount of resources to the refurbishment of the district heating network. The strategy of refurbishment is to identify critical line sections and to allocate renovation measures to these areas. Refurbishment is part of the total optimisation of production.