Stanford ran water beneath mirror-like rooftop panels; they cooled it 3–5°C below the surrounding air by sending heat into space

Researchers at Stanford have created innovative panels that cool water exclusively using sunlight and mirrors. These panels effectively reflect sunlight while releasing heat into space, resulting in significant reductions in water temperatures. Trials conducted on a Stanford rooftop have demonstrated remarkable cooling effects. Further modeling for Las Vegas has suggested that this technology could lead to major electricity savings for climate control in buildings.