Australian wind and solar project sized at remarkable 70 gigawatts – as big as the country’s main grid

The world’s biggest wind and solar project, planned for a remote desert region in south-east of Western Australia, has lodged its application for state environmental approvals with an upgraded target of a mind-boggling 70 gigawatts of wind and solar capacity – as big as the country’s main grid.

The Western Green Energy Hub envisages up to 3,000 wind turbines – some of them potentially sized at up to 20 megawatts each – and six million solar panels installed across 2.29 million hectares of pastoral leases and crown lands.

It will stretch hundreds of kilometres from north-west of Eucla, near the state border with South Australia, towards Cocklebiddy and north of the Eyre Highway to south of the Trans Australian Railway. It will be built in stages over 30 years and aims to produce 3.5 million tonnes of green hydrogen a year.

The proposal is being put forward by InterContinental Energy, which specialises in projects at such a grand scale, and CWP Global. Both are shareholders in the smaller 26 GW Australian Renewable Energy Hub in the Pilbara in the north of the state, which is now led by global oil giant BP.

The other partner is Mirning Green Energy Limited (MGEL), a commercial subsidiary of Mirning Traditional Lands Aboriginal Corporation (MTLAC), which is the registered native title representative body.

The AREH now appears geared more towards generating electricity for domestic consumption, particularly for the big mining projects in the region, and new green industries.

It will also likely have a green hydrogen component, but the Western Green Energy Hub appears fully committed to green hydrogen and ammonia, despite doubts over the extent to which those technologies will be able to replace other technologies, particularly when the transport of those molecules is involved.

Previous iterations of the Western Green Energy Hub had talked of a 50 GW project, but the scale of the project now is equivalent to the total capacity of the country’s entire main grid, known as the National Electricity Market.

It will also produce nearly as much power. “At full development the proposal may generate over 200 TWh of renewable energy, dependent upon the mix and size of wind and solar,” the document says.

“This is similar in magnitude to Australia’s current total generation and provides a major opportunity for domestic and international green fuel supply, and ultimately domestic power distribution, offsetting approximately 22 million tonnes of CO2 emissions per year.”

The proponents say it will include 35 separate solar farms, each surrounded by wind turbines and including centrally sited hydrogen electrolysers, as well as electrical infrastructure, pumping and cooling systems, production facilities for green ammonia, data centres, workshops and worker villages.

The coastal and offshore components of the project will comprise a marine offloading facility, desalination plant, brine pipeline and an ammonia (or other vector) export pipeline. A workers village – accommodating up to 8,000 people – is also envisaged.

0. “A ‘nodal’ concept will be adopted, where approximately 2-3 GW ‘nodes’ of wind and solar renewable power will be developed, with an approximately 1.5 GW electrolyser and/or data centre set within the centre of each node,” the document says.

“The proposal will be implemented over a nominal seven stages, which will ultimately result in the installation of up to approximately 35 such nodes, generating up to approximately 70 GW of renewable energy from up to approximately 60 million solar modules and up to approximately 3,000 turbines.”

The proposal gives no starting date, and it is likely to take many years to work through the environmental processes – both state and federal. It faces opposition from some quarters, including from the Bob Brown Foundation that has already raised concerns about the potential impact on the regions underground caves, rivers and lakes.

The proponents says they propose to use rock anchor foundations into the limestone rock, rather than excavating and installing massive concrete foundations, although the cranes mounting the towers will need a surface concrete pad of 80 by 40 metres.

It says mass concreting and foundations for the solar arrays will be avoided, with maximum use of precast elements and relatively small equipment such as excavators, bobcats, tractors and robot rovers.

The application to the EPA says up 27,188 hectares of native vegetation, representing approximately 1.2% of the development envelope, will be cleared, but most of it temporarily.

It says close to two-thirds of this clearing footprint (60.6%) will be immediately rehabilitated following the construction of the proposal, as approximately 16,464 ha is required for construction purposes only.