Resumen: A PV system on the rooftop is an easy and cost-effective way which allows consumers to independently meet a part of own electricity need. From an economic and financial perspective, consumers reduce the electricity bill and save money. These savings can be reinvested in actions aimed at the increase in energy efficiency, so triggering a worthy process of improvement. From a social perspective, consumers exploit renewable energy sources, so contributing to the environmental preservation by reducing the greenhouse gas emissions. The opportunities described above are evidently reserved to those users who have ample space for installing a PV system; on the contrary, users who live in apartment buildings in the cities are excluded. For the latter category, smart cities may represent a solution. Indeed, smart cities can offer to all citizen the same opportunities in the pair of renewable energy source exploitation and sustainable development. As an example, citizens living in a rural area have large roofs; their existing or new PV plants can be oversized with respect to the local demand, and the overgeneration may serve citizens living in a built-up area. Although very simple, this initiative brings citizens close to each other and relevantly joins them in a process of social development... Idioma: Inglés DOI: 10.1155/2017/3574859 Año: 2017 Publicado en: INTERNATIONAL JOURNAL OF PHOTOENERGY 2017 (2017), 3574859 [2 pp] ISSN: 1110-662X Factor impacto JCR: 1.547 (2017) Categ. JCR: CHEMISTRY, PHYSICAL rank: 105 / 146 = 0.719 (2017) - Q3 - T3 Categ. JCR: PHYSICS, ATOMIC, MOLECULAR & CHEMICAL rank: 25 / 36 = 0.694 (2017) - Q3 - T3 Categ. JCR: OPTICS rank: 54 / 94 = 0.574 (2017) - Q3 - T2 Categ. JCR: ENERGY & FUELS rank: 64 / 97 = 0.66 (2017) - Q3 - T2 Factor impacto SCIMAGO: 0.341 - Chemistry (miscellaneous) (Q2) - Materials Science (miscellaneous) (Q2) - Renewable Energy, Sustainability and the Environment (Q3) - Atomic and Molecular Physics, and Optics (Q3)