TenneT  B.V. is the national Transmission System Operator of the Netherlands, headquartered in Arnhem. Controlled and owned by the Dutch government, it is responsible for overseeing the operation of the 380 and 220 kV high-voltage grid throughout the Netherlands and its interconnections with neighbouring countries. It is additionally responsible for the 150 kV grid in South Holland following a 249-million acquisition of the regional system operator Transportnet Zuid-Holland in 2003.