[en] After having outlined that photovoltaic solar energy is a leader of renewable energies, available and abundant, and a key for the development of territories, this guide outlines what photovoltaic energy can bring to a territory on an economic, environmental and social point of view. It briefly denies some popular beliefs which criticise this energy, briefly presents the different types of photovoltaic plants, and indicates what a community can do to facilitate the development of installations and to mobilise actors. Then, it describes the six key steps to comply with when launching a solar project: to look for a land for the project, to adapt the local planning document (PLU), to implement a call for projects and a call for expression of interest, to support the project holder in his application for a building permit, to submit the project to the call for projects of the Energy Regulation Commission (CRE), and to implement the project