The 2025 Eskom Expo International Science Fair (ISF) ended on a high note as outstanding young scientists were rewarded with generous cash prizes for their rigorous and innovative research projects.

The fair, held at the Convention Centre at Emperors Palace in Kempton Park from 6 to 10 October 2025, brought together the brightest young scientists from South Africa, Lesotho, Namibia, Zimbabwe, Ireland, India and Russia.

The 2025 Top Senior Scientist, winning a R100,000 cash prize, was Christopher May from Otto du Plessis High School, representing the Port Elizabeth Region with the research project, “Differential Geometric Modelling of Sound Signals and Ultrasound Imaging”. The Grade 12 learner was selected as the Top Senior Scientist by a panel of Chief Judges who were impressed with his sound reasoning, logical arguments, and grasp of complex mathematics concepts. May designed a method to analyse the properties of sound using differential geometry. He created a geometric model of a sound wave and thereafter applied differentiation techniques to analyse its properties. He then went on to apply this method to ultrasound imaging where he successfully enhanced features such as subtle edges and the textures of anatomical structures. This resulted in enhanced medical imaging and improved diagnostic accuracy. May’s research highlights the value of mathematics as a tool to improve health care.   

Khushi Lall from Tyger Valley College, representing the Northern Gauteng Region with the research project, “Garlic: Nature's Secret to Food Preservation”, was the 2025 Top Junior Scientist recipient, winning a R75,000 cash prize. Food preservation has become a challenge globally because of the rise of resistant microbes. This was the motivation behind Lall’s research project. The Grade 9 learner impressed the Chief Judges with her remarkable understanding of bacteria such as Staphylococcus aureus and her exceptional precision when executing laboratory techniques. According to the Chief Judges, such scientific investigative skills combined with reasoning and logical thinking, is the mark of a scientist in the making.   

Lethabo Kgwete from Moleshatlou Secondary School, representing the Capricorn Region with the research project “The Effect of Livestock Green Compost Tea”, was awarded Top Development School and received a cash prize of R75,000. The Grade 11 learner investigated the effect of compost on crop yield. Motivated by the challenges faced by small scale farmers in rural areas such as access to affordable and sustainable fertilisers, Kgwete developed a cost-effective and eco-friendly compost called the Livestock Green Compost Tea. This Compost tea was prepared by combining fruit peels, dry grass, leaf litter, water, wood ash, eggshells, and other organic matter in a steeping container. The mixture was brewed for several days, producing a nutrient-rich liquid. The treated crops (tomatoes, spinach, and onions) consistently showed greater height increases and faster overall growth. Lethabo’s research holds much promise for increasing crop yield through sustainable green fertilisers. 

Eskom Development Foundation Acting Chief Executive Officer, Mologadi Motshele, said: “Eskom is incredibly proud of the young scientists who have participated in the Eskom Expo initiative this year, gaining valuable knowledge, skills, and insights as they explore the dynamic fields of science, technology, engineering, mathematics, and innovation (STEMI).” 

“Each year, thousands of learners benefit from Eskom Expo, gaining access to opportunities that would otherwise be out of their reach. We encourage other like-minded school learners to take an interest in this initiative and consider pursuing careers in STEMI fields. By doing so, they can become the architects of a brighter and more prosperous South Africa for future generations. Over time, Eskom’s sustained support has not only empowered individual learners but has also strengthened the nation’s future skills base, driving transformation and excellence in science education.”

A total of 30 Gold, 77 Silver and 131 Bronze medals were awarded at the Grand Awards ceremony, while the much sought-after opportunity to represent South Africa at prominent international science fairs in Taiwan, Tunisia, China, Indonesia, the USA, and Türkiye was awarded to deserving learners with the help of various long-standing sponsors of the Eskom Expo. These will be announced in the coming months.

Eskom Expo Executive Director, Parthy Chetty, said, “We extend our heartfelt congratulations to the brilliant winners of the International Science Fair. Your ingenuity, perseverance and passion for discovery inspire us all. This achievement is not only a celebration of scientific excellence but a powerful reminder of what’s possible when curiosity meets opportunity. To students everywhere: let this be your spark. STEM subjects open doors to solving global challenges, shaping the future, and making a lasting impact. Whether in labs, classrooms, or communities, your ideas matter. Keep asking questions, keep exploring and know that your journey in science starts now.”