In a ground-breaking initiative, scientists at ETH Zurich in Switzerland have made great progress towards solar energy. They have reached temperatures as high as 1,832 degrees Fahrenheit (1,000 degrees Celsius) by utilizing sunlight, an accomplishment that is usually dependent on fossil fuels.
In the modern world, temperatures above 1,800 degrees Fahrenheit are necessary to manufacture essential commodities like steel, glass, and cement. These industries and ceramics make up a significant portion of the world’s energy consumption, mainly derived from fossil fuels and increasing carbon emissions.
Solving this problem using solar energy was the brainchild of Emiliano Casati, a lecturer at the Department of Mechanical and Process Engineering. Their method aimed to improve the performance of solar receivers when using sunlight for heating purposes. The team utilized semitransparent materials, such as quartz, to successfully trap solar energy, unlike prior systems that relied only on concentrating sunlight.
As Casati stated, “The light reaches the solar absorber, which converts it into heat and whose temperatures increase, but the re-emitted infrared radiation is partly re-absorbed by the additional layer, thus reducing losses to the environment and increasing the efficiency of the device.”
The scientists created a heat-trapping apparatus using an opaque silicon disc and a synthetic quartz rod. They proved by careful experimentation that the quartz rod remained at 1,112 degrees Fahrenheit (600 degrees Celsius), and the absorber plate reached 1,922 degrees Fahrenheit (1,050 degrees Celsius) under simulated sunlight equivalent to 136 suns.
The development highlights solar thermal trapping’s potential for practical industrial uses. The team measured the efficiency of the quartz under various situations using heat transfer modeling, showing significant gains when well-insulated. They are also looking into different materials and techniques to improve temperature thresholds even more.
Casati commented on the industry’s timeline for implementation, emphasizing the necessity of a thorough techno-economic analysis to determine feasibility. He reiterated, “It is technically ready, and a techno-economic analysis (beyond the scope of the current work) is needed to understand better how to implement this.”
This groundbreaking advancement advances the use of solar energy and signals a paradigm shift in industrial processes towards cleaner, more sustainable ones, which is essential for achieving carbon neutrality.