Refrigerators and air conditioners devour around 20 percent of the world’s energy, and are a growing source of greenhouse gas emissions. Now researchers have devised a curious technique to produce cooling by unwinding tightly twisted wires. The method, reported in Science, could offer an energy-efficient and sustainable alternative to today’s cooling systems.

In addition to hogging energy, today’s refrigeration technologies also rely on circulating coolant gases called hydrofluorocarbons. These gases trap much more heat than carbon dioxide and can leak into the atmosphere during manufacturing, use, or when an AC or refrigerator is disposed improperly.