Posted: 04 Nov. 2020 05 min. read

All the buzz about the inaugural WoSP as coal gets stung

he Western Australia Energy Transformation Taskforce recently released the inaugural inaugural Whole of System Plan (WoSP)- a 20-year roadmap for the South West Interconnected System (SWIS), outlining the least-cost path to the future of WA’s principal electricity system. This publication is the first comprehensive planning study of its kind for the SWIS and presents four scenarios of system evolution to 2040. Similar to the east coast’s Integrated System Plan (ISP), this publication will guide investment and policy decisions towards a least-cost future pathway.

What could the future hold for the SWIS?

While the four scenarios paint different pictures for the future of the SWIS, all scenarios reach the following conclusions:

  • Coal contribution to meeting SWIS demand reduces from 44% today to below 16% in all scenarios and as low as 7% in the Double Bubble scenario by 2040, due to the escalating need for generation flexibility driving coal to become economically uncompetitive;
  • Rooftop PV uptake will continue to increase. Currently, WA has the third largest uptake of rooftop solar out of Australian states and territories, at 31.3% of all dwellings;
  • No major transmission network augmentation is required in the short- to medium-term;
  • Batteries play an important role in essential system (strength) services provision;
  • New gas capacity is only required in the two high demand scenarios;
  • Emissions intensity of the grid decreases regardless of demand increases. Under all scenarios, over 70% of generation capacity is renewable by 2040 compared with 34% today.


How does it compare to the NEM’s future?

The least-cost change in generation mix for the SWIS to 2040 under each scenario is shown in Figure 1. In all scenarios, investment in new wind precedes investment in utility-scale solar, and the majority of new entry consists of wind, solar and batteries. The ISP paints a similar picture for the east coast, with exiting coal capacity replaced by a mix of wind, solar and dispatchable storage. One notable difference is the ISP’s emphasis on network infrastructure investment’s role in a least-cost future. Unlike the SWIS, the NEM spreads vaster than most other grids in the world, and often suffers from congestion due to its lack of interconnection.

Figure 1 Capacity mix changes between 2020 and 2040 under the four WoSP scenarios

Source: Deloitte analysis of WoSP modelling outputs


So what’s next for WA?

The WA government is busily undertaking several streams of market reform involving distributed energy resources, essential system services, network access arrangements and the transition to 5-minute settlements.

With high levels of rooftop PV, industrial mining loads and retiring coal capacity, WA is in a unique position to lead Australia’s energy transition and unlock economic prosperity.

More about authors

Shira Samocha

Shira Samocha

Senior Analyst, Energy Transition

Shira is a senior analyst in energy, with deep understanding of Australia’s electricity markets and renewable energy. She specialises in electricity market modelling, scenario modelling including rapid transformation of the energy sector and robust analysis to better inform clients in generation, networks, manufacturing and government across the energy sector. Shira is experienced in generator feasibility studies, energy procurement strategy and Power Purchase Agreements, policy analysis, scenario modelling and techno-commercial analysis within the electricity industry. Within Deloitte, she has developed a number of market-leading models of the Australian National Electricity Market (NEM) and Wholesale Energy Market (WEM), a revenue-maximizing battery operation algorithm and a dynamic energy procurement optimiser tool. 

Kumar Padisetti

Kumar Padisetti

Partner, Financial Advisory

Kumar is a Partner in the Financial Advisory practice and is responsible for the Energy and Resources Sector. He specialises in portfolio management, policy advice, commercial and financial analysis, market modelling (electricity, gas and renewable energy), strategic positioning and assisting clients with growth strategies. Kumar helps his clients make future decisions with confidence.