Tieverkon

tieverkko, literally the electrical distribution network, denotes the part of the power system that delivers electricity from higher‑voltage transmission lines to end users. In Finland it operates mainly at medium and low voltages, typically 10–20 kV and 0.4 kV, with step‑down transformations at substations to households, businesses and public services. The tieverkko includes distribution substations, feeders, overhead lines and underground cables, transformers, protection and control equipment, meters, and the associated switching infrastructure.

Distribution system operators (DSOs) own and operate the tieverkko under licenses issued in accordance with Finnish and EU electricity market regulation. They connect new customers, perform routine maintenance, coordinate with the transmission system operator, and manage fault response and restoration. The network is also subject to quality and reliability standards, with tariffs and access procedures designed to ensure fair and non‑discriminatory connection and use.

In recent years, the Finnish distribution network has been modernizing to accommodate distributed energy resources such as rooftop solar, small wind, energy storage, and increasing electric vehicle charging. Smart meters, remote monitoring, and automation technologies are used to improve fault location, outage management, and voltage control. Challenges include aging infrastructure in some regions, extreme weather resilience, cybersecurity, and the need to balance reliability with the growth of DER. The tieverkko remains a critical element of the Finnish electricity system, providing the last mile of delivery to consumers and industries.