With the weather and seasons changing atypically everywhere around the world due to climate change, most scientists and governments are concerned about the probability of fossil fuels becoming extinct in the future and the lack of use of renewable resources. The use of fossil fuels is one of the biggest causes of climate change due to the greenhouse gases they produce. Therefore, scientists are trying to find new types of renewable energy sources that can easily be implemented by governments. Researchers at Jordan’s Hussein Technical University and Qatar University have developed a new type of solar tower that can work 24/7 and produce more than double the power a normal solar tower produces. This new kind of solar tower uses twin technologies, which entails building a large and a small tower, the larger of which encloses the smaller one and uses airflow through two pairs of turbines to generate power.
Solar towers have been in development for years but never came to the mainstream because of their lack of ability to create enough power compared to how expensive they were to build. A standard solar tower harnesses the energy of the sun to heat the air beneath its massive circular glass collector, which is suspended several meters above the ground. The collector has a gentle upward slope leading to a tall central tower, through which hot air rushes to escape and is converted into energy by turbines. The early design's low thermal efficiency—much lower than that of solar panels—is the problem, according to the researchers, who reported their findings in the journal Energy Reports. Low thermal efficiency also means that the towers must be very large for them to produce enough energy, which raises costs and is one of the main reasons they are not popular. There were attempts to make these towers efficient, like raising the height of the chimneys or improving ventilation, but these efforts didn’t have much success.
Therefore, researchers came up with the idea to build another tower around the first one. Sprinklers at the top of the second tower spray a "mist of water," which is quickly absorbed by the "dry, hot air”. When the water is absorbed, the air becomes “colder and heavier” and with the help of gravity, the air drops down the outer tower in various columns. This results in a downward wind that spins the turbines located at the bottom of the outer tower. At noon, when the temperature is at its highest and the humidity is at its lowest, the tower performs best. Contrary to solar panels, which can only work in the daytime, this tower can work 24/7 because solar irradiance doesn’t have a direct impact on the efficiency of the inner tower. Researchers also found that the solar twin tower system can produce 2.14 times the energy of a normal solar tower, which is predictable since the air spins turbines and produces energy both while going up and down.
Even though the new development is a step in the right direction to make solar towers more efficient and widespread, there are still limitations to their design. First of all, the solar twin towers are greatly impacted by heat and humidity, so they can only be used in hot and dry environments. The necessity for constant water to cool the air is another problem when using it in hot desert environments, even though the towers work best in these conditions.
In conclusion, the towers still need to be improved a lot, and the researchers say that future work on the subject will try to integrate other types of renewable energy in order to overcome current limitations, do a deep techno-economic analysis of the project to better understand how efficient it is, and take a closer look at its scalability.
Paleja, Ameya. “New Twin-Tech Solar Tower Generates Twice the Power, 24/7.” Interestingengineering, 6 Dec. 2023, Accessed 7 Jan. 2024.
Patel, Prachi. “A Clever Twist in Solar Tower Design Produces Power 24/7.” Anthropocene, 14 Dec. 2023, Accessed 7 Jan. 2024.
Sanderson (c_sanderson), Cosmo. “Twin-Technology Solar Tower Could ‘Deliver Power Day and Night.’” Recharge | Latest Renewable Energy News, 5 Dec. 2023, Accessed 7 Jan. 2024.