Performance challenges with solar cookers

It is very difficult to be completely dependent on a solar cooker for cooking unless thermal storage is added, and this can increase costs significantly. Without storage, solar cookers - especially for commercial purposes - will also require a conventional cooker which can be used when sunlight is not sufficient or on rainy days.

Vacuum tube cookers can work even when the sun is low, and also work well on moderately cloudy days. But these are much more expensive than simple box type solar cookers.