To accurately portray the state's solar resource, you need two maps. That is because different collector types use the sun in different ways. Collectors that focus the sun (like a magnifying glass) can reach high temperatures and efficiencies. These are called concentrating collectors. Typically, these collectors are on a tracker, so they always face the sun directly. Because these collectors focus the sun's rays, they only use the direct rays coming straight from the sun.
Other solar collectors are simply flat panels that can be mounted on a roof or on the ground. Called flat-plate collectors, these are typically fixed in a tilted position correlated to the latitude of the location. This allows the collector to best capture the sun. These collectors can use both the direct rays from the sun and reflected light that comes through a cloud or off the ground. Because they use all available sunlight, flatplate collectors are the best choice for many northern states. Therefore, this site gives you two maps: one is the resource for a concentrating collector and one is the resource for a flat-plate collector.
What do the maps mean? For flat-plate collectors, Mississippi has a good, useful resource throughout the state. For concentrating collectors, Mississippi could pursue some types of technologies, but large scale thermal electricity systems are not effective with this resource.
Source: U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy