Fridge that needs no power: Don’t expect it to churn out ice cubes but this 130-litre “village water cooler” uses the simple concept of evaporation to keep vegetables fresh. The fridge walls are filled with charcoal and pieces of earthen pots. When water trickles from an overhead tank, the walls soak it and keep the inside cool at around 24 degrees Celsius when the outside temperature is around 40 degree Celsius. And at just Rs 700, it may spell boon for many village households.

Algae for global warming: Certain algae use Carbon Dioxide to generate Oxygen. With this simple concept, students and faculty of the Department of Biochemical Engineering and Biotechnology have come up with a solution for global warming. With a chart they explain if power plants, the biggest contributors to global warming, transfer their Carbon Dioxide to an algae tank, it can be used to counter the threat. Experiments are on to apply the concept effectively.

Dishwasher that saves water: While a normal dishwasher uses water to clean dishes, this gadget uses 30 per cent water and 70 per cent air to do the same. The machine, which has nozzles that spray water and air, is a good option for places where water is scarce. It is the innovation of the students of M.Tech Design Engineering.

Ceiling fan that heats the room: Here’s a ceiling fan for both summer and winter. The fan has heating plates fitted on its three blades, which can be switched on during winter to raise the room temperature by 10 degrees Celsius. And the plates can be fixed “at a cost as low as Rs 750,” Mudit Raj, one of the inventors, says. However, watch your power bill, as the fan called “Winter Bliss” guzzles 1050 KW of electricity.