Tammisto Electricity Substation / Kivinen Rusanen Architects

The Tammisto Electricity Substation site in Vantaa has served the Helsinki metropolitan area as a central power grid hub for decades. The oldest systems on the site needed modernization to improve their reliability, capacity, and safety. To achieve this, the Finnish main grid operator, Fingrid Oyj, constructed a new building to house a 110 kV Gas-Insulated Switchgear (GIS) system, replacing an extensive, ageing air-insulated switchyard. The project also included the construction of new powerline structures, fences, a backup power generator, extensive landscaping, and fresh greenery. The construction process was carefully phased to minimize disruptions to ongoing substation and grid operations, and to ensure a smooth transition. The project also allows for future expansion of the substation's capacity, future-proofing it for the growing need for electricity.