The difficulties in integration renewable energy devices demonstrated that experience had to be gained in this area. The third and most recent integration attempt is demonstrated in the 'Solar Kitchen', a community kitchen for preparing 2000 meals a day. The concept began to be implemented in 1994. Since solar energy is abundant in southern India, using steam as the heat transfer medium for preparing the meals was the obvious choice. The innovative decision to integrate in the building a fixed spherical solar bowl concentrator of 15 meter diameter determined, to a large extent, the design and technology applications used within the building itself.
Renewable energy features The solar bowl is positioned at the western end of the first floor.
Composite granite blocks were used for the foundations. Walls in compressed earth blocks support the whole structure. A total of 96 prefabricated ferrocement elements were cast and hoisted in place to form a perfect fixed spherical bowl. Each single mirror piece had to be hand placed with an accuracy of 5 to 10 arc minutes, achieved with a simple laser pointer placed at the centre of the sphere. A tilted fixed mast supports a moving receiver which can rotate in all directions around a double-axis articulation placed at the centre of the sphere and balanced by a counterweight.