Oulu University Hospital treats approximately 140,000 patients annually, which in 2019, for example, meant 537,449 treatment visits. An uninterrupted and adequate electricity supply is a prerequisite for patients to be treated safely in hospitals.

OYS’ power supply has previously suffered unexpected interruptions due to, for example, careless excavation work, from which the hospital was left without electricity and reliant on its own backup generators. This has raised concerns not only for the hospital, but also for the network company, which is helping to ensure the supply of electricity to a socially critical actor such as the hospital.

Capacity for the 2030s by renewing electricity connections

OYS’ goal as the world's smartest hospital demands increasing the capacity of electricity distribution. Previous power supply solutions were becoming insufficient, and the hospital was in dire need of help to enable increasing electricity consumption. Oulun Energia Sähköverkko Oy implemented a solution for the hospital that ensures the reliability of electricity supply, enables maintenance without interruption, and can sufficiently cover possible consumption peaks.

Oulun Energia Sähköverkko Oy strengthened the electricity supply in two ways. Firstly, the power of the Oulunsuu substation transformer was increased by replacing the previous 10 MVA main transformer with a 16 MVA transformer. Secondly, a 16 MVA transformer was installed for the Hiukkavaara substation, from which a 20 kilovolt backup connection to the hospital was set up.

In practice, this means that reliable and uninterrupted electricity use was ensured by doubling the electricity supply and increasing the power. If the main power supply fails, the emergency power supply can be activated quickly, so that the interruption time is minimal compared to the previous implementation. The power consumption can be gauged by comparing it to the electricity consumption of a single-family house: the transformers used for the hospital would cover the electricity demand of around 2000 electrically heated single-family houses. The solutions were implemented in such a way that, in the future, it will still be possible to increase the power smoothly if necessary.

Seamless collaboration

Sauli Kurttila, who is the Director of Technical Services in the Northern Ostrobothnia Hospital District, feels that cooperation with Oulun Energia Sähköverkko Oy has gone very well. “The renewal of the connections was completed even earlier than planned. The project proceeded well and smoothly,” says Kurttila. “The capacity problem was solved and the new wiring connections also make it possible to increase the power if necessary by replacing the transformers. Users are also satisfied when there are no disruptions and electricity distribution works.”