Girls’Day 2025 at the High-Flux Solar Furnace
Six young girls had the opportunity to explore the High-Flux Solar Furnace at the DLR facility in Cologne-Porz as part of the annual Girls’Day initiative. During their visit, they engaged in a variety of experiments aimed at demonstrating how to harness and concentrate solar energy for sustainable use. The primary goal of Girls’Day is to inspire young women to develop an interest in science, technology, engineering, and mathematics (STEM) fields.
Experiencing the Power of the Sun
The capabilities of solar energy captivated the six schoolgirls during their hands-on experience at the High-Flux Solar Furnace. Through a series of experiments, they discovered how solar power can be amplified, starting with a simple magnifying glass. DLR scientist Christian initiated the demonstration by focusing sunlight through the lens onto a cardboard box, quickly igniting it and leaving a charred mark. The swift reaction surprised the young visitors, highlighting the potency of concentrated sunlight.
Experimenting with a Magnifying Glass
In their first experiment, the girls employed magnifying glasses to ignite a cardboard box. Wearing protective goggles, they observed the process and then tried it themselves. The concentration of sunlight could increase between 50 to 1,000 times, generating temperatures sufficient to ignite paper at approximately 180 to 360 degrees Celsius. Christian illustrated the concept by placing his hand between the magnifying glass and the paper, explaining that adjusting the distance altered the focal point and the heat intensity.
Harnessing Solar Power to Ignite Materials
The next experiment involved a large mirror on-site, equipped with a disc-shaped reflector that automatically tracks the sun’s position. When activated, the mirror directed solar radiation to a specific focal point, which Christian demonstrated using a water spray to visualize the light reflections. He challenged the students to see if they could ignite wood using this concentrated sunlight. Skeptical at first, the girls were amazed when the wood quickly began to smoke and eventually caught fire.
Melting Metal with Solar Energy
In another exciting experiment, the students aimed to see if they could melt metal using concentrated solar power. Christian provided each girl with a 5-cent coin, explaining that stainless steel melts at around 1,200 degrees Celsius, while the mirror could concentrate sunlight up to 10,000 times. After placing the coin in front of the mirror and activating the solar beam, they were thrilled to find that the coin had developed a hole after cooling.
Conducting High-Temperature Experiments
The students were then introduced to an even larger mirror, measuring 57 square meters, which directed sunlight onto a bank of 159 smaller mirrors arranged in a honeycomb pattern. This setup, known as the concentrator, allowed for experiments to be conducted at temperatures reaching up to 2,500 degrees Celsius. Inside the experimental facility, the students witnessed a high-tech environment filled with computer screens where scientists can adjust mirrors and control solar radiation exposure.
Innovative Uses of Solar Energy
During the visit, Christian explained the broader applications of solar energy, including the production of hydrogen and synthesis gas, which can serve as fuels. One particularly intriguing project discussed was the concept of building a village on the moon. A team at the High-Flux Solar Furnace has developed a 3D printing method that utilizes solar energy to create building blocks from lunar dust. This innovative approach suggests that solar power could play a vital role in future moon colonization efforts.
Inspiring the Next Generation in STEM
The girls’ experience at the solar furnace was part of Girls’Day, an event designed to encourage girls and women to pursue careers in technology, science, and research. Earlier that day, they had conducted experiments with infrared light at the DLR School_Lab in Cologne, showcasing the initiative’s commitment to fostering interest in STEM disciplines among young women.
