The North-West Interconnected System (NWIS) is located within the Pilbara region and comprises a number of interconnected electricity networks with different owners. The three largest participants in the NWIS are Horizon Power (GTE), and Alinta Energy and Rio Tinto (which are privately owned). Other large mining companies including Roy Hill, BHP and Fortescue Metals Group also own major energy infrastructure in the NWIS and the broader Pilbara region to service their individual operations.
Pilbara networks are regulated under Part 8A of the Electricity Industry Act 2004. There are two key components to the regulation of Pilbara networks, including:
- a light-handed access regime to facilitate third party access to designated electricity network assets in the Pilbara, which is codified in the Pilbara Networks Access Code (PNAC); and
- an independent system operator (ISO), which will operate under the Pilbara networks rules (PNR).
The Pilbara independent system operation functions are performed by Pilbara ISOCo. Pilbara ISOCo is an incorporated not-for-profit company limited by guarantee under the Corporations Act 2001 (Commonwealth). The founding members of Pilbara ISOCo are the three main operators of electricity networks in the Pilbara: Horizon Power, Alinta Energy and Rio Tinto.