From the “Australia's Science Channel” website, posted on August 17, 2017:

The world’s largest solar thermal power plant will be coming to South Australia – big plans lead to big reactions. Read what the experts have to say. 

Plans to build the world’s largest solar thermal power plant in Port Augusta, South Australia, were announced by Jay Weatherill, Premier of South Australia, today. Solar Thermal Power is generated by using a large array of mirrors (heliostats) to reflect and concentrate energy from the sun to heating molten salt. This is then able to generate steam to drive electricity generating turbines. Solar thermal is one way that solar power can be stored and used at night.

The plant is scheduled to be in operation by 2020, and is estimated to produce 495 gigawatt hours of power annually, or enough to power more than 90,000 homes. The 150 mega-watt system will be completely emission free.

Here are reactions from researchers around Australia.

Dr Ariel Liebman is the Deputy Director for Monash Energy Materials and Systems Institute (MEMSI), at Monash University

“The Port Augusta Solar Thermal plant will be a great complement to the range of new technologies now in South Australia and the rest of the nation such as wind, solar PV and electric battery such as the Neoen/Tesla battery announced last month. Solar thermal with storage is an ideal partner to the other new technologies whose growing deployment is now unstoppable. Being able to store its own energy output in a thermal way (not electrically such as in the case of lithium ion) makes this a truly dispatchable renewable technology.

While this particular project appears to be uneconomic without the state government subsidy, de-risking early stage investment is the government’s role and as more deployment of new technologies will bring the cost down as industry learns how to manufacture and deploy at scale. We need the most diverse mix of technologies possible if we are to ensure we limit climate change based temperature rises to two degrees if not 1.5 degrees.

It will add to the downward pressure on wholesale energy prices although at the size of 150 MW, the impact will be quite small and it is unlikely to be felt in the end-consumer bill, particularly as the majority of the retail electricity price rises seen over the past ten years have little to do with the cost of energy generation but more to do with failures in retail competition as well and wholesale market ownership concentration and insufficient transmission inter-connector capacity in the National Electricity Market.”

Dr Mark Diesendorf is Associate Professor and Deputy Director of the Institute of Environmental Studies at the University of New South Wales

“An excellent decision! Port Augusta’s concentrated solar thermal power station with thermal storage will be a dispatchable source of renewable power.

In other words, it will supply power on demand. Along with the Tesla battery and open-cycle gas turbines, it will balance the fluctuations of the variable renewable energy sources, wind and solar PV.

Wasim Saman is a Professor of Sustainable Energy Engineering at the University of South Australia

“This is first large scale application of solar thermal generation in Australia which has been operating successfully in Europe, USA and Africa. The significance of solar thermal generation lies in its ability to provide energy virtually on demand through the use of thermal energy storage to store heat for running the power turbines.

This is a substantially more economical way of storing energy than using batteries. While this technology is perhaps a decade behind solar PV generation, many future world energy forecasts include a considerable proportion of this technology in tomorrow’s energy mix.”

Dr Matthew Stocks is a Research Fellow in the Research School of Engineering at The Australian National University

“We have lots to learn about how solar thermal can contribute to a stable, low cost, low emission electrical system, and the announced system will be an important step in understanding the potential of solar thermal.

One of the big challenges for solar thermal as a storage tool is that it can only store heat. If there is an excess of electricity in the system because the wind is blowing strong, it cannot efficiently use it to store electrical power to shift the energy to times of shortage, unlike batteries and pumped hydro.

It is not yet clear whether it will deliver a better outcome than wind and solar with electrical storage.”

Honorary Associate Professor Hugh Saddler is a Research Associate at the Centre for Climate Economy and Policy, at The Australian National University

“This concentrating solar thermal power station will be Australia’s first major solar thermal power station.  This will make it one of the most important milestones along Australia’s transition to a low emission electricity system.

The project will deliver both direct generation of electricity when the sun is shining plus up to eight hours of molten salt thermal energy storage.

The storage will allow the power station to keep supplying electricity at full capacity for some hours after the sun has set and peak evening demand for electricity has passed. It will thus combine both generation and storage in the one plant, greatly enhancing the reliability and security of the electricity grid in SA.

At a reported 125 MW it will be large enough to supply 5 per cent of the state’s current total daily electricity consumption.

The reported contract price to the state government of $78 per MWh is not much higher than recent contract wind generation prices and at or below prices for electricity from current solar photovoltaic power stations, neither of which include energy storage. It is also well below the estimated cost of any new coal fired power station in Australia, and well below the spot wholesale price of electricity in the SA market region, which has averaged between $110 and $120 per MWh since March this year.”

AuthorRay Dennis