Kerosene lamps typically require 5 ml to 42 ml of kerosene per hour for light output varying from 8 lumens to 67 lumens.
If we assume that higher capacity lamp is used for 4 hours in the night and the lower capacity lamp for 8 hours in the night, 208 ml of kerosene is required in a day and for a month 6 litres will be required. In India, Kerosene is sold at subsidized rate of Rs. 12.50 and at this rate it come to Rs.75 per month for the consumer. If a solar lamp is sold at Rs. 600, it can mean a saving of Rs.300 per month in the first year itself for the consumer. The payback period comes to 8 months.
The country will save on subsidy which is around Rs.20 per litre now.
Danish artist Olafur Eliasson wants to offer solar lamp for $10 to consumers in India.
It will be sold to retailers at $5.
News in Economic Times 3 august 2012.