CSP industry targets Australia’s dispatchable energy gap
8th November 2018
By Zara Maung
Retired coal power opens up opportunity for thermal energy storage
With 15-16MW of Australia’s coal power due to retire in the next 15 years, CSP companies are offering a thermal storage solution to fill the country’s peak energy gap.
Although traditionally dominated by coal, Australia has already hit its 23.5% renewable energy target for 2020 and significantly increased its PV capacity, particularly on rooftops. However, as more of the country’s coal fired power plants start to be retired, an energy gap is anticipated during evening peak demand, when energy from PV becomes unavailable.
CSP with thermal energy storage presents a renewable energy solution to the conundrum, with CSP research from CSIRO claiming that thermal energy storage, providing 6 to 12 hours of stored energy, will become more price competitive than PV battery storage over the next decade.
CSP is already proving its worth in Australia as an off grid solution. Operating since October 2016, the world’s first integrated energy system based on CSP – designed and delivered by Aalborg CSP – went into operation to secure sustainable operation of Sundrop Farms’ greenhouse facilities in the Australian desert, at Port Augusta near Adelaide. Its off grid 36 MW tower solution, based entirely on client requirements, uses a steam turbine that provides 20,000 MWh annual heat, 1,700 MWh electricity and 250,000 m3 desalinated water for the 200,000 m2 greenhouse. According to Svante Bundgaard, CEO of Aalborg CSP, the plant generates 10% more energy than anticipated.
Figure 1. Aalborg CSP’s Sundrop Plant (Port Augusta, Australia)
With the health impacts of coal power under scrutiny as well as its climate impacts, there is growing appetite for renewable energy infrastructure in the country.
Daniel Thompson, vice president of development at SolarReserve, developer of Port Augusta’s new CSP/PV Hybrid Energy Project says CSP potential in Australia currently depends on local renewable power targets, which currently vary significantly between the country’s regions. Another crucial factor, he says, is the transmission network, which tends not to coincide with the most solar rich areas in the country, making connection a problem.
Regarding federal renewable energy targets, Thompson says solar CSP is disadvantaged compared to other renewables. CSP has a higher price point but has a different value proposition to wind and solar PV, as it is can be used to satisfy evening peak energy demand, Thompson argues. However, the current renewables market in Australia is not structured to fit the CSP industry, as renewable energy certificates are given out equally, whether or not they satisfy peak demand.
SolarReserve’s Port Augusta project was lobbied for by the local community for years, in response to the local coal plant’s negative health impacts. Comprising a 150 MW CSP tower and 1,200 MWh storage, thermal energy is collected as molten salt, providing 8 hours (1,200 MW-hours) of full load energy storage. A partnership was also set up with a local mining company to share the transmission network.
The 20 year generation agreement was signed with the South Australian government last August and construction of the plant, which has a predicted 30-40 year operating life, is due to start in 2019.
Figure 2. Location of Solar Reserve’s Aurora Solar Energy Project (Source: SolarReserve)
Having modelled 21 of Australia’s top load events, Wes Stein, chief solar technology research scientist at CSIRO, claims CSP with 5 hours of storage could avoid the need for grid augmentation in 72% of constrained sites.
CSIRO’s research center in Newcastle, Australia, aims to increase the cost effectiveness of CSP, as well as increasing its versatility by developing technology that operates efficiently in smaller decentralized plants.
The two small research towers in Newcastle are testing 700c receivers, using molten salt towers and CO2 super critical turbines, and aim to achieve a turbine efficiency of more than 50 percent for 25 or 50 MW capacity CSP projects, which is usually unachievable using steam turbines.
Stein is also testing phase change material (PCM) storage at the Newcastle facility. Everything changes when you move to higher temperatures, he says, and although PCM is furthest away from commercial reality, it could represent the future of energy storage.