The invention provides systems and methods for provisioning a site with an energy system such as a solar energy system. A system according to an embodiment of the invention comprises a user interface module providing a graphical user interface for receiving information from a user, for example a potential purchaser. The information includes location information for the site to be provisioned. An image retrieval module is coupled to the user interface module and to a source of geographical information. The image retrieval module retrieves at least one image of the site corresponding to the location provided by the user. A sizing module is configured to enable a user to measure an installation surface represented in the image. Energy system components are selected based on the measurements.