Systematic efforts to promote the use of box solar cookers began in 1979 in Gujarat, along with similar efforts in other parts of the country. During this 15 year period only about 34,000 units have been sold in Gujarat. This is much better than other states. But on absolute basis this number is very small compared to the vast number of households, who live in rural areas, use wood as fuel and experience great difficulty in getting it. Thus solar cooker is yet a long way from becoming a substitute for conventional devices. It is argued that if the cooker can be made less vulnerable to climatic factors, its acceptability will increase. With this in view, the utility of a built-in backup source is explored in this paper.