A team led by Prasant Saini of the IIT Mandi has developed an electric-solar hybrid oven. The Solar Thermal-Electric Powered Cooking Oven (STEPCO) can cook food in solar, electric or hybrid mode. The device, which has oven, toaster and griller features, costs around ₹12,000; the inventors say that the payback period is 2.3 years in hybrid mode and 3.7 years in only solar mode. It is good for a variety of foods, including cakes and pizza.

“The STEPCO oven demonstrated significantly higher energy efficiency in hybrid mode — 63 per cent — compared with 35 per cent in electric mode and 4 per cent in solar mode,” says a paper on the device, published in Energy.

The main heating chamber has three sides of aluminium alloy; the other three are of toughened glass. The three-glass sides are the top, bottom, and door (front side). The top and bottom surfaces of the heating chamber are made of transparent, toughened glass to allow entry of concentrated solar radiation. This ensures sufficient solar thermal heating of the oven when operating in solar or hybrid mode. “The heating elements present in the oven are responsible for providing electrical heating. They are used only when operating STEPCO in electric/hybrid mode. A microcontroller-based smart control system controls the operation of these elements,” the paper says.

Additionally, the STEPCO oven has the environmental benefit of emitting very little CO2 during the cooking process when used in hybrid mode and zero CO2 emissions when used in solar mode.

As many as 2.8 billion people did not have access to clean cooking in 2015, and this number is expected to decline only to 2.3 billion by 2030.