An effective way to enlarge the utilization of renewable energy consists in creating a correct interface between producers, consumers, and storage devices, i.e., a so-called “energy hub”. This opens a difficult challenge, especially in the urban areas where the availability of room for the installation of renewable plants is limited. This paper considers a university campus in the center of Lisbon that requires a significant amount of electricity and natural gas to support the internal activities. The idea is to fulfil part of the energy consumption of the campus with the excess of energy supplied by solar systems installed in the surrounding residential buildings. The goal is to find the number and type of solar equipment that maximize the reduction of annual energy costs of both residents and campus, where the campus is seen as a virtual storage. Results of the optimization show that, considering the best-exposed 100 buildings in a radius of 500 m around the campus, the campus can reduce the annual energy expenses up to 8.61%, whereas the money-saving for the residents is of the order of 24% to 29%, depending on solar exposure. A sensitivity analysis shows also the higher benefits for both the campus and users deriving from expected decreasing costs of photo-voltaic (PV) panels.