Thanks for your response.
Experience around the world has shown that solar cookers can never be THE cooking solution for the simple reason that they require the cook to stand in unshaded hot sun around mid-day. Most people cook in the morning and evening. A cooking device that cannot be turned on at will but whose utility depends on the weather, can only be a secondary solution. In remote regions with sunshine, solar cookers may find favor in homes without access to firewood or LPG, but even there, the intermittency factor prevents such cookers from being the main cooking device in a home. Most low-income households cannot afford two types of cooking devices.
The World Bank is committed to helping the poor get access to clean cooking that is sustainable, affordable, and sensitive to local cooking traditions. In addition to promoting clean cookstoves that meet these criteria as well as local needs, the Bank Group has encouraged the supplementary use of solar cookers where appropriate. The challenge is to engineer a solar cooker that is affordable, can be used indoors, works at night, is built of locally available materials, and fits existing cooking practices. Until solar cookers meet those criteria, their viability will remain limited except in specific cases.
With the current cost and utility of solar cookers, these should perhaps be encouraged more in developed countries where more affluent users with sensitivity for the environment could adopt these in lieu of gas and electric cooking. It is especially suited to replace outdoor gas and charcoal barbecue grills. Perhaps there is more merit in promoting this than in pressing poor households to adopt solar cooking.