Quoting from the site
“~~ HOW DOES THE PARABOLIC SOLAR STEAM COOKING SYSTEM WORK ~~
The Solar Steam cooking system installed at Shirdi has parabolic concentrators / dishes (called Scheffler dishes after its inventor)
installed on the terrace of Sai Prasad Building No.2.
A Parabolic type concentrating Solar Steam cooking system was commissioned at Shri Saibaba Sansthan, Shirdi on 24th May`2002.
This system received financial assistance of 50% of the total project cost from the Ministry of Non-Conventional Energy Sources, GoI.
The Solar parabolic concentrators reflect and concentrate the Solar rays on the receivers placed in focus.
Water coming from the steam headers placed above the header centres is received from bottom of the receiver,
gets heated up to due to heat generated (about 5500C) due to concentration of solar rays on the receivers and
get pushed up via top pipe of receiver into the header.
The principle of anything that gets heated is pushed up is called Thermo-Siphon principle.
The advantage of thermosiphon principle is no pumping (thus no electricity) is needed to create circulation since the heated water is
pushed into the header and cooler water from the same headers come into the receivers for heating.
The cycle continues till it reaches 1000C and gets converted into steam.
The header is only filled and thus steam generated gets accumulated in the upper half of the steam header.
The temperature and pressure of steam generated keeps on increasing and heat is stored till the steam is drawn for cooking into the kitchen.
All the dishes rotate continuously along with the movement of thesun, always concentrating the solar rays on the receivers.
This movement of concentrators is called tracking, which is continuous and is controlled by the fully automatic timer mechanism.
A Timer mechanism powered by Solar cells (which convert sunlight into electricity) gradually rotates the mirrors, so that they constantly face the sun as it moves across the sky. The entire system is run by one operator. Only once during the day i.e. in the early morning the dishes have to be turned manually onto the morning position,
subsequently the automatic tracking takes over.
The speciality of this solar cooker invented by Wolfgang Scheffler is that it generates steam unlike the earlier models where the cooking pot was placed at the focal point of the parabolic minor. This system is integrated with the existing boiler to ensure continued cooking even at night and during rain or cloudy weather.
The solar cooking system installed at Shirdi follows the Thermosiphon principle and so does not need electrical power or pump.