WEM Reform Rules

The Wholesale Electricity Market in Western Australia is established under the Electricity Industry (Wholesale Electricity Market) Regulations 2004 and is governed by the Wholesale Electricity Market Rules (WEM Rules). 

As part of WEM Reform, the WEM Rules have been re-written by the Energy Policy WA (EPWA), a process which is supported by AEMO. On 24 December 2020, the majority of the WEM Rules were gazetted, representing a major milestone for WEM Reform and enabling AEMO to progress the development of WEM Procedures. Further amendments have been gazetted by the WA Government in a series of “Tranches” of Amending Rules, with the most recent Tranche gazetted in March 2023.

The current version of the WEM Rules can be found on the Energy Policy WA website, along with copies of the various Amending Rules. Energy Policy WA also produces a Companion Version of the WEM Rules, that incorporates Amending Rules that have been made by the Minister for Energy to give effect to the Energy Transformation Strategy, but which have not yet commenced.

The WEM Rules govern the operation of the SWIS and the electricity market, including the wholesale sale and purchase of electricity, Reserve Capacity and Essential System Services. This includes detailing the roles and functions of AEMO and other governance bodies.

The WA Government’s Coordinator of Energy is responsible for maintaining and developing the WEM Rules in consultation with the Market Advisory Committee. There are no restrictions on who can propose a rule change. Proponents must submit Rule Change Proposals to the Coordinator in a prescribed format including the reasons why they think the rule change is desirable. Once proposed, rule changes follow a strict process which includes industry consultation. You can read more about this process in AEMO's Wholesale Electricity Market Design Summary.