Let there be light, the engineers thought. And they used not electricity, but just a dome, a pipe and sunlight. They named it ‘Surya Jyoti’, and it dispels the darkness in the homes of the poor.
The micro-solar dome started as a pilot project to stream diffused sunlight into poorly-lit rooms through the roof in thatched, tiled or tin-roofed houses in the Sundarbans in West Bengal and in Tripura. Now, it has been commercialised.
“It works on the principle of capturing sunlight using a micro-solar dome. The light is filtered through a PVC pipe with a highly reflective lining. Bright light emerges at the other end (within the room) through a glass shade,” said S.P. Gon Chaudhuri, former director of the West Bengal Renewable Energy Development Agency and now the chairman of the Helsinki-based International Solar Innovation Council.
Easy to install
A roof-tile can be removed to install this, and it works equally well in a tin-roofed building too.
The device has been developed by N.B. Institute for Rural Technology and adopted by the Centre’s Department of Science and Technology under its Technological Advancement for Rural Areas programme. The device, priced between ₹100-300, comes in three models. Around 5,000 solar domes are in use in the slums of Delhi and in West Bengal, Tripura, Assam, Madhya Pradesh, Karnataka and Uttarakhand. The Science and Technology Ministry estimates that ‘Surya Jyoti’ can help some 10 million households. These are off-grid, in urban and rural areas, without reliable access to electricity. The domes provide light equivalent to a 60W bulb.
Anupam Baral, who owns Geetanjali Enterprises, a solar equipment firm, said his company was making the domes. Besides a basic model, two others come fitted with solar photo-voltaic panels and a lithium-ion battery to store energy when sunlight is scarce, also enabling mobile device charging. Recently, Central Electronics, a PSU, was asked to make the domes, Mr. Gon Chaudhuri said.
