This article has been adapted from the article,, “Reflections: ten years of solar steam systems for cooking in India,” by Deepak Gadhia, Managing Director, Gadhia Solar Energy Systems Pvt. Ltd published in Akshay Urja (Vol.1 Issue 5).

Among the other renewable sources, solar energy based systems and devices are on the forefront of resolving our day-to-day energy demand.Solar water heating systems, solar cookers, solar home lighting,solar generators, solar lanterns, solar air heaters, solar traffic lights,solar road studs, solar blinkers, and so on are the most common devices and systems that are commercially available in the market.

Gadhia Solar has been on the forefront in identifying appropriate
technologies and indigenizing them. The company introduced
Seifert Parabolic Solar Cookers for domestic cooking and Scheffler
Parabolic Concentrators for community cooking.

For direct solar cooking systems,solar rays are reflected through a small opening in the north-facing wall of the kitchen and further reflected and bundled onto secondary reflector placed below a blackened cooking vessel placed in the kitchen.This enables cooking within the comforts of the kitchen. The temperature at focus is about 400 ºC.Therefore, practically all items can be cooked. A single dish can cook for 50 persons per mealtime.

For community cooking Solar Steam Cooking system is used.
In Solar Steam cooking solar rays falling onto the dishes are reflected and concentrated onto the receivers.Due to the high temperatures achieved (450–650 °C), the water within the receiver is converted into steam.The steam is sent to the kitchen through insulated pipelines to the steam cooking vessels, for fast, hygienic cooking in a clean environment. There are two types of steam
cooking vessels a) vessels where steam is injected directly
into the food to cook items like rice and vegetables
b) double-jacketed vessels where steam circulates through the
outside jacket of the vessel heating the food inside. It can
help boil milk, tea, soup, and so on since injecting steam into
the food would dilute it.

For the full article click here(pdf link).