Concentrated solar thermal power touted as part of Queensland's clean energy future
LOL. What's old is new again. Solar thermal is an old idea that has often been tried but always disappoints. The best known example was the huge Ivanpah project (from 2013) in the Mojave desert.
You don't hear much about it now as it never functioned anywhere near its capacity and produced very expensive electricity. And there has NEVER been any return on the couple of billion spent constructing it.
The most amusing thing about it is that it used vast amounts of natural gas to get itself going in the morning and when it was cloudy. There was at one stage a proposal to reclassify it as a gas-powered power station because on many occasions more of its output came from burning gas than from its solar furnaces
The thing such plants are best at is chewing up subsidies from deluded governments
The most comparable previous project to the one described below was the Tonopah project in the Nevdada desert. In it, more than 10,000 mirrors were to focus the sun’s heat on a tower to produce steam and heat a tank containing molten salt that would generate power at night. However, the technology proved unreliable and expensive to build and operate.
Since it began operating in 2015, repeated leaks from its molten salt tank resulted in the power plant going off-line repeatedly. Unable to solve that and other problems at the facility, the power plant ceased all operations in April 2019.
Super-heated NaCl (salt) is a very hard substance to handle and that generates big costs and losses
An Australian company says its technology can help solve the problem of around-the-clock clean energy as Queensland gears up to become a renewable energy powerhouse.
A chronic issue for the most common renewable energy sources — such as solar panels and wind farms — is an inability to store power, which forces the national grid to rely on coal-fired power overnight.
Vast Solar has been developing new technology for concentrated solar thermal power, a renewable energy source that powers more than 7 per cent of the Spanish national grid, and in which China is heavily investing.
Chief executive Craig Wood said the company had been developing concentrated solar power (CSP) technology for 13 years and was ready to scale up its prototypes — manufactured and tested in Goodna, near Ipswich — to contribute to the national grid.
"It's a direct replacement for the overnight energy that is provided by coal-fired power stations," he said.
"And importantly the technology uses the same skill sets that are currently used in those thermal power stations, just in a renewable context."
The technology uses large mirrors, or heliostats, to beam sunlight into an array on a tall tower.
Molten sodium is then pumped through the array and heated to more than 500 degrees Celsius.
That heated sodium can then be stored and used to generate steam to spin a turbine and drive electricity into the national grid — or as a clean energy source for large industry.
CSIRO head of solar research Greg Wilson said the technology could be located alongside a traditional photovoltaic solar farm, with the grid using solar panel energy during the day and switching to stored power at night.
"After hours when the batteries are all flat, and people want to continue with their air conditioner, or large industry wants to continue to work, that 12 hours of storage that the CSP plant provides allows us to have 24-hour renewable energy," Dr Wilson said.
The CSIRO has been working with Vast Solar on developing and testing its newest research in the field.
Mr Wood said CSP was now cheaper than coal or gas and emitted almost no carbon dioxide when deployed in a full-scale facility.
Released last week, Queensland's $62 billion renewable transition plan makes no mention of CSP technology but emphasises the role of solar power in its seven-year plan.
Mr Wood said the plan was "hugely exciting" and one in which CSP could play a role, "allowing us to use existing transmission infrastructure while providing new jobs for power plant workers".
Energy Minister Mick de Brenni said in a statement there would be "ample opportunities" for industry to work with the state government on the plan, "including proposals like CSP".
Vast Solar is developing a 30-megawatt test plant in Port Augusta, in South Australia, to demonstrate to government and investors that the technology can effectively contribute to the national grid.
The project has $110 million in federal concessional funding and once it has the go-ahead, could be up and running in three years, with a life span of three decades.
"We're working on securing the grid connection for that project," Mr Wood said.