A better alternative

a new set of improved solar devices including the solar cooker, water heater, solar wax melter and solar drier has been developed by the Consortium of Rural Technologies ( cort ), a Delhi based voluntary group engaged in the development of appropriate technology for the villages. The existing devices are mostly expensive, difficult to maintain and repair and, moreover, are not available everywhere.

The new models, developed by Dinesh Bhardwaj of cort , use low-cost materials, most of which are locally available. None of the devices use glass or mirror as in the case of the solar cooker presently available in the market. Soft wood is used for the construction of the frame; thick, black polythene, transparent polythene, acetylene sheet and thin metal sheets made of either aluminium or iron is used for the construction of the heating chamber and inner bottom lining of the device. Dry wheat husk is used for insulation and blackboard paint is used to paint the body black.

An extensive training programme for the rural women will ensure that they are exposed to the scientific principles involved in the functioning of the solar devices and that they are able to operate them with ease. The training programme has been chalked out by the Centre for Science, Technology and Environmental Policy Study, New Delhi in collaboration with cort . The programme will also train rural women in the construction and maintenance of these solar devices. A follow-up programme has also been planned to assess the efficiency of these devices. In this, the villagers will be asked to provide monthly feedback about the devices. This will enable cort to further improve these innovations.

The modified solar devices can be used for cooking, heating, drying and melting operations. The solar wax melter can melt 20-25 kg of wax a day and the melted wax can be effectively used in candle making operations. The dryers, on the other hand, can be used in the home-run potato making units in the village.

The new devices are also affordable. The solar cooker costs only Rs 350, compared to Rs 900 of the existing model. Solar drier is available for Rs 250, water heater device for Rs 300 and the wax melter (20 kg capacity) for Rs 1,500. The currently available model of the wax melter is rather expensive at Rs 5,000.

cort is of the opinion that primary-level educated people can handle the construction of the devices whereas existing models can only be processed in the industry. As the devices can be built by the users themselves, repair works can also be undertaken by them.