Vast plans $600m “baseload” concentrated solar power plant for Mt Isa

Australian solar thermal developer Vast Solar has unveiled plans to take its technology into the mainstream, unveiling a $600 million proposal to build a “baseload” solar plant in Mt Isa that will combine solar thermal, solar PV, battery storage and fast-acting gas generators.

The plan, being supported and advised by Energy Estate,  is to build a plant that will provide 50MW of continuous 24/7 power for Mt Isa, making up for the imminent closure of the Mica Creek gas plant and positioning itself for further developments should the Copperstring 2.0 transmission link is built between the mining city and Townsville.

Vast Solar has been operating a small , award-winning 1MW pilot plant at Jemalong near Forbes in western NSW for the last two and a half years, and recently passed up an opportunity to build a full scale commercial plant in the region because the solar resource wasn’t quite good enough. (It sold it to Genex Power which is building a solar PV plant instead).

In Mt Isa, Vast Solar CEO Craig Wood says, there is a solar resource that is the second best in the world behind the Atacama Desert in Chile, and an isolated grid where consumers have to, quite literally, supply their own gas, give it to the local gas generator to burn and then buy the electricity back at sky-high prices.

The North West Queensland Hybrid Power Project will be the biggest hybrid plant in Australia, and will combine 60MW of solar PV and a 52MW battery storage facility with 10 minutes storage – which will provide the bulk of daytime power- and the 50MW concentrated solar power facility with more than 14 hours of storage, and reciprocating gas generators that will provide night-time power and fill in the gaps.

The battery has low level of storage because its major role is to balance out impacts of clouds and the like, and fill in the gap if gas generators need to be fired up.

The $600 million ticket price may seem sky high for just 50MW of baseload capacity, but Wood says the output will be delivered at a significant discount to the current gas-fired generation, which is probably costing local customers around $150 a megawatt hour – more than twice the average price of the main grid.

Solar thermal technology has been showing promise for years, but despite some deployments in the US, Spain, northern Africa, the Middle East and Chile, they have yet to be deployed at scale in Australia.

 

The US company SolarReserve was well advanced on a project to build a massive solar tower power plant with storage near Port Augusta, but despite signing a long term contract with the South Australia government it failed to secure finance after technology problems emerged at its Ivanpah plant in Nevada.

 

Wood says the Mt Isa market may be easier to crack than the main grid, because the only competition comes from much more expensive gas, which has to be piped thousands of kilometres.

 

“CSP has a history of false starts,” Wood says. “At its core, it tracks back to technology. We’ve had 2.5 years operating our grid connected pilot plant, and we have been refining the technology and making sure the product works. It’s not without risks, and certainly some of the current and former competitors have significant issues in those areas.”

 

The core of Vast Solar’s technology is using liquid sodium as its heat transfer fluid, and a modular system that creates what will be 8MW units comprised of heliostats (mirrors) that reflect sunlight to a receiver on top of a tower, where the fluid is heated (and then stored).

 

The Mt Isa project would see the towers grow from 27m high to 50m, slightly bigger heliostats, and bigger modules.

 

Before the project goes ahead, it will need to secure a power purchase agreement with customers to help it get finance, and those customers may include those currently served by the Mica Creek power station. And it will also approach the Australian Renewable Energy Agency (should it still exist), the Clean Energy Finance Corporation and the North Australia Infrastructure Facility.

 

All going well, financial close could be reached in mid 2021, and generation beginning in 2023 after about two years of construction.

 

It already has the support of the local mayor Danielle Slade.

 

“Not only is this exactly the type of project our community needs, but with clear, sunny skies for most of the year and an extra hour of sunlight to the rest of Queensland, Mount Isa is the ideal area in which to locate it,” Slade said in a statement.

“Our local industries are crying out for affordable electricity and, coupled with the CopperString 2.0 project, this solar initiative will help to make that happen.

“As well as bringing direct employment opportunities, it will indirectly safeguard many other jobs by generating competitively priced, low-emissions electricity that can power local businesses and resources operations, making Mount Isa an even more attractive city in which to live and invest. We will be working closely with Vast Solar to help them realise their exciting vision.”

Giles Parkinson

Giles Parkinson is founder and editor of Renew Economy, and is also the founder of One Step Off The Grid and founder/editor of The Driven. Giles has been a journalist for 35 years and is a former business and deputy editor of the Australian Financial Review.

https://reneweconomy.com.au