The photo is sourced from WaterNSW
As a rule, PSPPs are equipped with two water reservoirs with an elevation difference: in the hours of low demand, cheaper electricity from the common grid is used to pump water from the lower reservoir into the upper one, from which it gets discharged in the hours of growing demand, setting off power generators. This design makes it possible to use wind and solar generators more efficiently, as these facilities are utilised on an intermittent basis. This is especially true for Australia, where fossil energy sources are being replaced by renewable ones. In the period from 2010 to 2022, the installed capacity of local coal-fired TPPs fell by 6.7 GW, while the capacity of solar panels and wind generators increased by 28.6 GW and 8.7 GW, respectively, according to data from Ember and Global Energy Monitor.
However, combinations of various sources are used not only within the common grid, but also as part of individual projects. Among them is the Carwarp solar hydropower plant, which was launched in the Australian state of Victoria in 2023. The plant consists of four solar towers, on which mirrors are placed in a semicircle, directing light onto the receiving tower. The latter is equipped with 400 solar modules with a capacity of 2.5 kilowatts (kW) of electricity and 5 kW of thermal energy each. The thermal energy extracted from the modules is stored as hot water in an insulated tank, whereas the electricity they generate powers the chiller, a refrigeration unit that cools the water to near freezing temperatures. When demand goes up, hot and cold water is used to run a Rankine cycle turbine that converts water vapour into electricity.
Another example of combining various sources can be found in the off-grid hybrid power units that are installed by Rosseti in remote villages of the Transbaikal Territory and the Tomsk Region. The units consist of solar panels, diesel generators and energy storage devices: diesel generators supply power in the morning and evening, while electricity from solar panels is used during the day. Excess electricity is fed to the storage devices, which power the off-grid system at night.
