The Hiệp Hòa 500kV transformer station is located in Hiệp Hòa district, covering an area of 17 hectare and being the largest of its kind in Việt Nam with the total cost of US $58 million.
As one of the major projects of the Sơn La Hydropower Plant, the station includes two 500kV transformer towers with a combined capacity of 1,800 MVA and other 500kV, 220kV and 35kV distribution equipment./.