No power, no bills: This cooling system could replace your AC

Researchers at King Abdullah University of Science and Technology have developed a new cooling system that operates without electricity, using a combination of salt and solar energy to create a sustainable alternative to traditional air conditioning.

The system, called Nescod, is designed to address rising global temperatures and the growing demand for cooling in regions where access to electricity remains limited.

Instead of relying on compressors or electric motors, the technology uses ammonium nitrate, a compound commonly found in fertilizers. When dissolved in water, it triggers an endothermic reaction — meaning it absorbs heat from its surroundings — producing a cooling effect.

In testing, researchers found that the system could reduce temperatures from 25°C to 3.6°C within 20 minutes, making it significantly more effective than similar salt-based solutions.

One of its key advantages is its ability to reset without power. After the cooling cycle, solar energy is used to evaporate the water, allowing the ammonium nitrate to crystallise and be reused. This creates a repeatable, electricity-free cooling process. The system can also collect evaporated water through solar distillation, improving efficiency.

The development comes at a time when cooling demand is rising sharply worldwide. The International Energy Agency estimates that air conditioning already accounts for around 10% of global electricity use, a figure expected to grow as temperatures increase.

Researchers say the Nescod system could have wide-ranging applications, from cooling homes and buildings to preserving food and storing temperature-sensitive goods in areas with unreliable power.

If scaled effectively, the technology could offer a low-cost, sustainable solution for millions of people living in hot climates without consistent access to electricity.