Jakelujohdoissa

Jakelujohdoissa refers to the network of electricity distribution lines and equipment that delivers electric power from substations to customers within a region. In the Finnish energy system it covers the lower part of the electrical grid, typically operating at low to medium voltages suitable for local and feeder distribution. The network includes conductors (overhead lines and underground cables), insulators, poles or trenches, transformers, switchgear, protection devices, and associated control and communication systems that together ensure safe and reliable delivery of electricity to homes, businesses, and public services.

Key components and topology

Distribution networks comprise both overhead and underground elements, chosen based on terrain, cost, and reliability considerations. Substations step voltage down from transmission levels to distribution levels and feed feeders that branch out to individual areas. Protective relays, fuses, and sectionalizers detect faults and isolate affected sections to minimize outages. Modern networks increasingly integrate remote monitoring and automation to improve fault location, isolation, and restoration times.

Regulation, operation, and reliability

Distribution system operators (DSOs) oversee the daily operation and maintenance of these networks, while national authorities set market rules and safety standards. In Finland, oversight and regulatory frameworks are administered to ensure safe operation, fair access to the grid, and reliable service. Reliability is tracked using indicators such as average outage duration and frequency, guiding planning and investment.

modernization and challenges

Recent developments focus on modernization through smart grid technologies, remote sensing, and automation, enabling better integration of distributed energy resources like rooftop solar, energy storage, and electric vehicles. Challenges include aging infrastructure, climate-induced weather risks, capacity planning, and the need to balance reliability with the growing share of decentralized generation and demand-side flexibility.