Scientists at the Massachusetts Institute of Technology (MIT) have created a cooling system that relies on evaporation and radiation but uses no electricity.

Traditional air conditioning systems use huge amounts of electricity and with the earth warming, use of air conditioners is projected to significantly increase. MITs new cooling system needs no power and just a little water.

The new cooling system could also be used to safely store food for longer periods of time particularly in countries with poor energy access.

The system can reduce the ambient air temperature by 9.3 degrees Celsius (19 degrees Fahrenheit). This allows for food to be stored at a safe temperature for up to three times longer.

The system is made of three layers of material. The first layer is made of Aerogel which is highly insulating but allows water vapor and radiation to pass through. The second layer is made of Hydrogel which acts like a sponge with the pores filled with water. At the bottom a mirror-like layer reflects incoming sunlight and prevents the system from heating up.

MIT postdoc and member of the team who designed the cooling system, Zhengmao Lu explained, “The novelty here is really just bringing together the radiative cooling feature, the evaporative cooling feature, and also the thermal insulation feature all together in one architecture.”

The main problem the system currently faces is the cost of Aerogel production. The research team is now exploring ways that Aerogel can be produced at a lower cost, although Lu admits it is impossible to know how long it will take before the cost of Aerogel will make the system practical for widespread commercial use.