The study published recently in the journal Energy Reports redesigns a system known as a Solar Tower Power Plant which consists of a chimney-like tower with a mechanical turbine at its base.
The system mainly consists of two components – a solar updraft system and a cooling downdraft structure.
As air within the tower is warmed by absorbing solar radiation, it creates an updraft that rises and activates wind turbines which in turn generate electricity.
However, this initial model developed in the 1980s by Spanish engineers was not adopted widely as it was costly due to its enormous size.
Conventional power plants of this design also have limited energy productivity, as they are dependent on solar radiation and work only during the daytime.
Although there were several improvements to this design over the years, such as the use of different cost-effective construction materials and better ventilation within the system as well as the use of multiple generators to boost the output, these developments only led to “modest” improvements.
Now, researchers from Qatar and Jordan have achieved much better results by coupling an improved updraft along with downdraft technology.
In the downdraft system, a pump carries water to the top of a tower where warm air collects and cools it.
The cooler air then falls through a cylinder as it becomes denser than the outside air.
Once the cooler air arrives at the base of the turbine, it drives it and generates electricity.
“The hot air instantly absorbs the water and descends the tower to interact with the turbines at the bottom to produce electricity,” scientists explain.
By combining two drafts in this new Twin Technology Solar System (TTSS), power can be generated even through the night as air from daytime sunlight retains heat, researchers say.
Simulations show TTSS can generate 752,763 kWh of electricity annually – or about the energy needed to power about 753 homes for nearly five weeks.
“This mode is independent of solar irradiance and can operate day and night,” they said, adding that it generates 2.14 folds more power than a traditional solar updraft system.
TTSS, they say, consists of an updraft tower of about 652 ft height and a 45-foot diameter with 10 downdraft towers circling the updraft tower.
While simulations showed it can generate power round the clock, scientists say the system’s reliance on water supply remains to be addressed.