|Abstract:||Stored solar cookers collect energy using existing parabolic solar cookers and store the heat in a vessel filled with a salt. This stored solar cooker enables users to cook even when there is no radiation from the sun.
The ability of the stored solar cooker to collect heat depends on the ambient conditions (solar radiation, percent cloud cover, temperature, and wind speed). Solar resource maps can quantify the global potential for solar energy use, but existing maps do not take storage aspects into account. Such a global resource map can be used to identify where the cookers may be most useful, and can also identify the parts of the world suitable for initial testing and development of stored solar thermal cooking.
An energy balance to describe the solar cooker was developed with inputs of solar radiation, fraction direct solar radiation, wind and temperature. Heat loss occurs due to convective, conductive, and radiative losses due to ambient conditions. The energy balance was created using a combination of theoretical equations and data and design parameters from a stored solar cooker under development. Outputs were energy stored in a day and number of vessels which can be charged.
A monthly world map of input was developed to combine with the energy balance using four times daily meteorological reanalysis data averaged over 19 years. Using the energy balance, the average amount of energy that can be stored was calculated. The resulting monthly world maps show the average daily energy which can be stored in the cooker, and how many days in a month at least one, two, and three vessels can be charged.
Percent cloud cover has the greatest effect on storage, and high percentage of cloud, resulting in low amounts of direct solar radiation, result in slow charging of the stored solar cooker. The length of day and the strength of the sunlight are also important in the ability to use the stored solar cooker. Additionally, locations with enough sunshine to reliably charge at least one stored solar cooker a day during most of the year are ideal for the stored solar cooker to be used.
Throughout the world, dry climates, climates with a long dry season with consistent daily cloud-free days, high elevations with dry seasons or a dry climate, and dry summer months are ideal for using the stored solar cooker reliably. It is recommended that the stored solar cooker be used in these regions.