Everybody’s Jaga Sodis

EVERYBODY?S JAGA SODIS

Dr A.Jagadeesh.Renewable Energy Specialist, 2/210 First Floor
Nawabpet, NELLORE 524 002, Andhra Pradesh , India

Ph: + 91 861 321580, Fax: + 91 861 331848
E-mail: a_jagadeesh3@yahoo.com

SODIS(Solar Disinfection) is being promoted in some countries. PET(Polyethylene) bottles are recommended to be put on a black surface for 5 hours. But I found PET bottles suffer from the following deficiencies:

1. The life of PET bottles is small
2. PET bottles degrade after long exposure to Sunlight
3. PET bottles turn brown after some days, thus the transmission of sunlight is reduced
4. Moreover one has to find a suitable elevated structure to
Place the Sodis. But placing the SODIS in the North-South
Direction gives optimum sunlight exposure

To improve the usage of SODIS and to make it cost-effective a MOBILE SODIS has been designed and tested.

It consists of a 36 cm length and 30 cm breadth wooden planks(two) and in each of the planks a 3 cm bottle shape is engraved which is coated with black colour. The two planks are joined so that they can be opened and closed like a photo album. Two stands are provided at the back of the wooden planks so that the angle can be cvaried. The DECLINATION angle has to be fixed according to the latitude of the place to get maximum efficiency.

A hook is provided so that the two planks can be closed. A handle to enable itto carry is also provided.

OPERATION:

Bottles are cleaned and water is put in bottles up to 75% and rinsed well for 20 minutes. Then the bottles are filled to the full. Each plank has provision to put two bottles of 1 litre.

To optimise the material of the bottle, it was experimented with both PET and glass bottles. Also in each of PET and GLASS bottles, traces of cardamom(elaichi in hindi), clove are put. Temperatures were measured after 5 hours of exposure to the sun by placing the unit in North-South direction as shown in the picture.

It was found that glass bottles give on an average 3 degrees Celsius higher temperature compared to Pet bottle. Interestingly the bottles in which the spices(Cardamom & Clove) are placed gave 2 degrees Celsius! Also one can put Tulasi leaves (STRYCHNOS POTATORUM after heating the water which gives taste as well as act like preservative.

In some countries Asbestas is banned. Also many countries Pet bottles for soft drink(example: Denmark) are not in use but only glass bottles. The glass bottles have an advantage in that they can be cleaned and generally the shape will be smooth(pet bottles have designs like curved where dust will be gathered ) .

ADVANTAGES:

1. The Unit is mobile and can be carried like a LAP TOP!
2. The unit costs just Rs 300(about 6 US$) and can be made
locally.
3. The unit is mobile and can be carried to picnics
4. Also black coloured polyethylene units can be manufactured on
A large scale which will be light and costs less.
5. The Units are modular
6. The unit occupies very little space
7. Since plant derivatives like Cardamom, Tulasi and Cloves are utilized they help in digestion and give fine flavour besides harmless
8. This is a simple and cost-effective way of providing drinking water at the rural level
9. The unit is expected to be a boon in developing countries
Global agencies, Governments & NGOs can promote this innovative but cost-effective unit.