Solar-Thermal Trap Generates Heat Exceeding 1,000 Degrees Celsius

Novel Device Harnesses Concentrated Sunlight for Industrial Processes

Scientists at ETH Zurich have developed a solar-thermal trap capable of capturing concentrated sunlight to generate extremely high temperatures for industrial applications.

Fueling Industry Without Fossil Fuels

Manufacturing cement, metals, and various chemical products requires temperatures that exceed 1,000 degrees Celsius. Currently, these high temperatures are primarily achieved by burning fossil fuels such as coal or natural gas, releasing significant amounts of greenhouse gases. Utilizing renewable electricity is not a viable alternative due to its inefficiency at such high temperatures.

The ETH Zurich research team, led by Dr. Emiliano Casati and Professor Aldo Steinfeld, has demonstrated a method that enables these industries to transition away from fossil fuels, as reported by SciTechDaily on May 28. Their findings are published in the journal Device.

Key Components of the Solar-Thermal Trap

The core component of the solar-thermal trap is a quartz tube that reached a temperature of 1,050 degrees Celsius in experiments, emitting a visible glow. (Image: ETH Zurich/Emiliano Casati)

Harnessing solar radiation, the researchers developed a solar-thermal trap capable of delivering the extreme temperatures required for industrial processes. The device consists of a quartz tube equipped with a ceramic absorber. Thanks to its optical properties, the absorber effectively absorbs sunlight and converts it into heat.

In their laboratory experiments, the team utilized a 30-centimeter-long quartz tube with a 7.5-centimeter diameter. Exposing it to simulated sunlight 135 times more intense than normal sunlight, they achieved temperatures of up to 1,050 degrees Celsius. Previous studies by other research groups had only managed to reach temperatures of 170 degrees Celsius with similar solar-thermal traps.

Advantages and Potential

Large-scale concentrating solar power systems have been implemented for solar electricity generation in locations such as Spain, the United States, and China. They typically operate at temperatures capped at 600 degrees Celsius. At higher temperatures, radiative heat loss becomes significant, reducing the efficiency of the plant. A key advantage of the solar-thermal trap developed by the ETH Zurich team is its ability to minimize radiative heat loss.

"Our approach dramatically improves the efficiency of solar energy absorption. Therefore, we are confident that the technology will further boost the implementation of high-temperature solar plants," said Casati. However, he also emphasized the need for further detailed technological and economic analyses.

Future Outlook

Casati is continuing his research to optimize the process. In the future, this technology could enable the use of solar energy not only for electricity generation but also for decarbonizing energy-intensive industries on a large scale. "The fight against climate change requires the decarbonization of energy as a whole," said Casati.

Summary

ETH Zurich researchers have developed a solar-thermal trap that harnesses concentrated sunlight to generate extremely high temperatures exceeding 1,000 degrees Celsius. This device has the potential to revolutionize industrial processes, enabling the transition away from fossil fuels and towards sustainable, solar-powered manufacturing.