The South West Interconnected System Transmission Plan: FAQ

The SWIS Transmission Plan outlines the Western Australian Government’s long-term strategy for upgrading and expanding the South West Interconnected System (SWIS) - the main electricity network that powers homes, businesses, and industry across the southern part of the state.

Developed by Energy Policy WA in collaboration with Western Power, the Plan sets out a phased approach over the next decade to build new transmission lines and upgrade existing ones, enabling cleaner, and more reliable energy to flow to where it’s needed.

The Plan is designed to support WA’s energy transition by delivering the infrastructure needed to unlock new renewable energy generation, facilitate more projects in major industrial precincts like the Western Trade Coast and Kemerton Strategic Industrial Area (SIA), and meet growing electricity demand from households and businesses. With an emphasis on staged investment, and flexibility for industry, the Plan lays the foundation for a cleaner energy future.

As planning for other transmission lines continues, we will engage with all communities that may be affected. Transmission is needed across the whole system to enable new renewable generation, and the specific project locations are part of the efficient development of the South West Interconnected System (SWIS). While these projects are designed to meet system-wide needs, they will also create local impacts and opportunities.

Not directly at a local level - but the build will improve overall system reliability. The transmission upgrades are focused on moving large volumes of renewable energy from where it is generated to where it is needed across the network.  This can help improve reliability of the whole network. 

Landowners who host major transmission infrastructure (200kV or higher) will receive compensation, assessed by an independent valuer at no cost to the landholder. Western Power will work directly with affected landholders to discuss options and agreements.

The State Government is committed to working with regional communities. While this Plan sets the high-level path for the next decade, detailed planning is still to be done. There will also be opportunities to provide feedback through upcoming power system planning processes.

We’ve already been working with Local Governments and Regional Development Commissions. Broader community engagement will follow, including face-to-face events and information resources to support your understanding of the energy transition and what this means for you and your community.

The Plan sets out the intended investments over the next 10 years, but the exact timing will be flexible to respond to industry needs. The Plan has three distinct phases — starting with Phase One to address the most urgent needs. Phase Two and Phase Three will be shaped by changes in energy demand and future planning processes like the Whole of System Plan.

New renewable projects and the transmission build will create jobs, skills opportunities and local contracts - particularly in regions near industrial zones and renewable energy resources. The Government is also exploring ways to ensure local businesses and workers benefit, including Aboriginal-owned businesses.

The impact of poles and wires transportation is limited as they can typically be placed on standard-sized trucks. 

Western Power and Main Roads WA are required to prepare Transport Management Plans that assess road impacts and protect the local environment. If any damage happens, it must be repaired by Western Power or its contractors.
 

Collie’s Just Transition support is focused on supporting the workers (and broader community) affected by the closure of coal power stations, and the associated coal mines, which have been the town’s main industry for over 100 years. While the changes in other areas may not be as large, the Government is committed to supporting all regions impacted by the energy transition.

The Government has set up a dedicated team to work on boosting housing supply in regional areas where new energy projects are being built – acknowledging the challenge in already tight housing markets.

Western Power is overseeing the building of the transmission projects by contractors.  Western Power and its contractors also operate and maintain the transmission network. PoweringWA is overseeing the bigger picture - working with Government, communities and industry to make sure the transition is coordinated, fair and beneficial for all. Energy Policy WA undertakes electricity system planning to ensure that future energy demand is met.

If your land is needed for new transmission infrastructure, you’ll be compensated fairly. An independent valuer (paid for by Western Power) will assess the value based on WA laws. The goal is always to reach a voluntary agreement. Compulsory acquisition would only happen as a last resort.

The Government knows that big infrastructure can bring change - and stress. PoweringWA works across departments to help manage these changes, make sure local voices are heard, and support communities to benefit from the energy transition - whether that’s job opportunities, training, or investment.

Western Power follows strict fire safety rules when building and maintaining powerlines. More detailed information on fire risk management will be shared in your local area as projects progress. Where lines are replaced by higher ones with less poles, fire risk can be reduced. 

The State Government is introducing a range of initiatives to enhance Western Australia’s manufacturing capabilities and to foster local content in transmission supply chains. This includes a $75 million investment, made through the Made in WA Plan, to support the establishment and growth of transmission component manufacturing facilities around Picton and Forrestfield. 

In addition to this investment, a Request For Information (RFI) has been released concurrently with the Plan to better understand existing local capability in the transmission manufacturing space.

Feedback from the RFI process will inform future support for the industry, helping the State Government invest in ways that efficiently grow local capacity and position WA businesses to capture opportunities from the energy transition. Furthermore, the Government is working to strengthen compliance requirements around existing obligations under the Western Australian Jobs Act 2017, and the Western Australian Industry Participation Strategy (WAIPS) to ensure the benefits of the energy transition are captured across the supply chain by local businesses, particularly manufacturers.
 

It is important the Plan balances meeting Western Australia’s clean energy needs, while also avoiding over-investment which could result in unnecessary costs for the State and network users.
WA hosts an abundance of high-quality wind resources spread across the State, many of which lie within or near the SWIS footprint. Several of these areas are captured in the Plan.

However, the Plan is designed to be flexible and agile. Beyond Phase One of the Plan, the timing and location of future transmission projects will remain responsive to energy demand and guided by detailed modelling. Dates for Phase One projects are defined in the Plan, and funding for Phase One projects will be committed as required to ensure timely delivery against these dates.

To ensure future builds meets industry and household's energy needs, decisions on transmission investments for Phases Two and Three will be informed by detailed system modelling, such as the annual Wholesale Electricity Market Electricity Statement of Opportunities (WEM ESOO), and the next Whole of System Plan (2027), which will be developed in close consultation with industry. 
Beyond that, projects will be assessed and reviewed through the annual Transmission System Plan and future WOSPs. 
 

Phase One Clean Energy Link projects will deliver the transmission build required to connect the new generation projects needed to phase out State-owned coal and meet WA’s growing electricity demand, while also connecting the new industrial demand loads that will drive a stronger, more diverse economy.

Dates for Phase One project are defined in the Plan, and funding for Phase One projects will be committed as required to ensure timely delivery against these dates. Clean Energy Link – North is under construction and will is scheduled to be operational by late 2027. Supported by over $1.2 billion in funding, including an allocation of $584 million at the 2025-26 State Budget, the project is strengthening the transmission network through Perth’s northern suburbs and beyond. It will upgrade the current mix of 132 kilovolt and 330 kV lines in the northern part of the SWIS network, including upgrading the existing transmission line between Neerabup and Three Springs to 330 kV to support the connection of future renewable generation projects, de-constrain existing generation and facilitate industrial loads in the Mid West.

The State Government has determined Clean Energy Link – North and Regans Reinforcement as priority projects under the Electricity Networks Access Code 2004, to ensure these projects are delivered at pace.  

 Over the longer-term, there may be areas in or adjacent to the existing SWIS footprint where private sector-led transmission could play a role. One such example is the Goldfields, where PoweringWA is currently investigating the development of a privately led common use transmission network - the Goldfields Regional Network.

Developers are also encouraged to engage with Energy Policy WA on ongoing power system planning work, such as the next Whole of System Plan (WOSP), planned for release in 2027. Details on the WOSP and updates will be shared on the Energy Policy WA website. 

Developers interested in pursuing privately funded transmission connection solutions can do so through Western Power’s existing Major Customer Connection Process. 

Additionally, Western Power will proactively engage with proponents located outside the State’s proposed future transmission investment areas to assess interest in progressing customer-funded solutions.
 

The State Government and Western Power undertook several iterative modelling and planning exercises, with an emphasis on least cost and reliability modelling, to inform the development of the Plan.

These exercises showed that renewable energy generation, firmed by battery storage and gas generation, is the most efficient way to replace the energy currently produced by coal, while also supporting future demand growth and maintaining system security and reliability.  

Wind and solar energy generation will provide large volumes of low-cost energy and, positioned across a diverse range of locations to enhance reliability, will form the foundation of a resilient low-emissions energy system.

Gas-fired generation and battery energy storage systems (BESS) will complement intermittent renewable generation, ensuring system security and reliability. BESS will store excess power generated by rooftop and large-scale solar during the middle of the day, allowing energy to be fed back into the grid to meet demand for electricity at other times – particularly during the evening peak after the sun sets. 

Gas-fired generation will provide a flexible source of power that can step in when intermittent renewable energy sources like solar and wind are not available. Gas will act as an important ‘bridge’ in WA’s energy transition as it helps keep the system stable as coal is phased out and renewable generation and storage capacity continues to grow.