A solar cooker is a device which is used to cook food directly under sun light without using Gas, LPG or electricity. It’s a clean process of outdoor cooking.
Always use non abrasive cleansers on your solar panels. An abrasive cleaner can scratch the surface of the panel and cause permanent damage and affect how well the solar panel works. There are commercial cleaning solutions to use or you can use a pool skimmer with a very soft cloth on it.