For the regional scale planning of the renewable energy production, it is required to systematically assess the availability of the resource and the convenience of its exploitation in each site individually. The GIS is the ideal tool to process large amounts of data that subtend the decision problem in a geographic dimension, to synthesize the models, and make them accessible. In this chapter, we present some analytical tools that are included in the architecture of GIS and extend its capabilities as a decision support system. The emphasis is on methods that automate issues such as selection of information, site classification, problems solving. An information system is outlined that has the ability to self-configure to maximize efficacy and efficiency of the data processing.