Western Australia


WEM Rules

WEM Regulations

The WEM is established under the Electricity Industry (Wholesale Electricity Market) Regulations 2004.

The WEM Regulations cover the responsibilities and functions of the responsible parties including AEMO, System Management, the IMO and the Electricity Review Board under the Wholesale Electricity Market Rules (Market Rules).

WEM Rules

The WEM Rules govern the operation of the WEM in the South West interconnected system. 

The WEM Rules detail the roles and functions of AEMO, System Management, the IMO and other governance bodies, and guide the operation of the market including the trading and dispatch of energy, the Reserve Capacity Mechanism and settlement.

The current WEM Rules consist of the Wholesale Electricity Market Amending Rules which were gazetted on 19 September 2006, together with all gazetted amendments made by the Minister for Energy prior to 15 December 2006 and amendments made by the IMO since 15 December 2006.

This consolidated version of the WEM Rules is provided as a clean copy for information. A hard copy is available for viewing in the IMO's office.

WEM Rules commencing 30 November 2015

The IMO’s market operations functions are being transferred to AEMO from 30 November 2015.

This transfer has necessitated a number of changes to the Wholesale Electricity Market (WEM) Rules, the Gas Services Information (GSI) Rules and their associated procedures.

On the 27 November 2015, these changes were gazetted by the Minister for Energy. The gazettal is available here.

The Public Utilities Office has provided the IMO with marked-up and clean versions of the WEM and GSI Rules, these are available on the IMO’s website here.

In accordance with the new transition rules, the IMO has updated the Market and GSI Procedures to reflect the split of functions between the IMO and AEMO. The procedures are also available at the above link.
WEM Rules - Chapters
Historical Versions of the Market Rules

Rule Changes

All Rule Change Proposals progressed since the commencement of the formal Rule Change Process on 15 December 2006 can be found here. Any amendments to the Market Rules prior to this time were progressed by the Public Utilities Office (former Office of Energy) on behalf of the Minister for Energy and can be accessed by contacting the Public Utilities Office