A Spanish research group from a well-known public university has developed an innovative solar oven to be used permanently outdoors that overcomes the disadvantages of existing solutions.
Solar cookers and ovens have several advantages, both environmental and health-related, as they do not use fossil fuels and avoid fire risks when used in open spaces for cooking. However, existing solutions still present several inconveniences that have impeded their generalized use.
Direct solar cookers (which directly heat food and/or beverages) need frequent sun tracking, they are sensitive to wind and pose burning and glaring risks. Besides, it is impossible to use them without direct sun and they are fast deteriorated when left outdoors.
Indirect solar cookers (which use a heat transporting fluid to transfer heat to the food and/or beverage and eventually serve as heat storage) tend to be slow and do not heat enough. Besides, they are expensive, complex and do not work properly during the morning and night, usually needing electricity.
Therefore, the proposed solar cooker has been conceived as a single body in the form of an oven that integrates three capacities: sun collection, heat storage and oven function (meaning a hot cavity that precludes the food or body of interest to be spoiled by dust or other agents as insects or bacteria). It can be used for different purposes: cooking, sterilisation or even heating tap water for cleaning or sanitary purposes.
Specifically designed to be permanently installed outdoors both for private (balconies, gardens, rooftops, etc.) and public uses (parks, beaches, resting areas, restaurants, schools, hospitals, etc.), this design is remarkably useful for its installation in poor areas or developing countries. This is explained by the fact that vegetable coals or refined fuels such as oil or butane are usually scarce/too costly in these areas, and the use of biomass frequently leads to serious health issues such as illnesses or deaths caused by the smoke. Besides, solar heat reduces the pressure on collecting wood and avoids deforestation.
The solar oven can also incorporate a Phase Change Material (PCM), capable of storing large amounts of energy and releasing them in the event of darkness for cooking and sterilising purposes, avoiding food spoiling regardless of the weather.
In its lower part, the oven includes a prismatic cavity that receives the heat collected by an upper flat plate collector by conduction. The whole set is thermally insulated and the design allows reaching temperatures above 100 ºC.
Its independence from electricity and any kind of fuel makes it suitable for many purposes. It is sustainable, it does not carry emissions or noises, it does not have any additional cost and it is available constantly, during day and night time. It does not use any exotic or costly primary materials or that are difficult to reach. Its use on natural spaces avoids fire risks posed by stoves and barbecues and also provides shadow to its users.
The University is currently looking for companies specialised in the urban or garden furniture, as well as the solar cookware sectors, in order to reach a license agreement or a commercial agreement for its development and commercialisation.