Stanwell signs up to $600 million solar thermal plan for Mt Isa

Sydney-based Vast Solar is looking to develop a $600 million hybrid power plant in Mount Isa combining solar PV, a large-scale battery and gas engines with a 50 MW solar thermal facility powered by the company’s proprietary technology.

Energy giant Stanwell announced on Monday it had signed a joint development agreement with Vast Solar. Stanwell will initially provide $5 million towards a feasibility study, with Vast Solar also providing $5 million.

Vast Solar unveiled plans for the North West Queensland Hybrid Power Plant last year. The project will integrate solar PV, battery storage and gas engines with Vast Solar’s own concentrated solar thermal (CSP) power technology, using mirrors and receiving towers to gather and store the sun’s energy.

Unlike traditional CSP technology that uses molten salt both as a heat transfer and for storage, Vast Solar has developed low cost, modular, technology with integrated thermal storage that uses sodium for heat transfer and molten salt for on-demand storage, both of which create steam to drive a turbine.

The technology has been trialled at Vast Solar’s 1 MW pilot plant, which has been delivering electricity to the grid since early 2018, and the company claims it allows plants to be configured with 4-16 hours of storage and generators of up to 500 MW.

Vast Solar said 85% of the output at the North West Queensland Hybrid Power Project would be zero carbon, with the rest generated from gas, and the project would deliver cheaper energy than alternative baseload generation options over its 30-year life.

The feasibility study, which will examine logistical details, planning requirements and financing, is expected to be completed later this year, with approvals expected early in 2022, followed by two years of construction. Early generation would start in 2023 due to a staggered build plan.

Stanwell CEO Richard Van Breda said projects such as the North West Queensland Hybrid Power Project “are integral to the development and diversification of our energy portfolio around the state”.

“This project illustrates our values by delivering a better Queensland through transitioning to a lower carbon future while still contributing to the economy, creating jobs and delivering low-cost energy to homes and businesses,” he said.

Stanwell was the original generator of power in Mount Isa before it shut its 218 MW Mica Creek Power Station at the end of 2020.

That has left the APA Group with its gas power stations the dominant generator in the region, which is not connected to the National Energy Market (NEM).

The region is however set to be linked to the NEM with state and federal governments fast-tracking support for the massive CopperString 2.0 high voltage transmission line connecting Mount Isa with Townsville.

Construction is yet to begin on the $1.5 billion transmission link but earlier this month CIMIC Group’s UGL and CPB Contractors announced they had signed early-stage contracts to construct the 1,100km high-voltage transmission line.