Decentralized renewable energy (DRE) refers to a system that uses renewable energy such as solar, wind, hydro, and biomass to provide reliable and CLEAN energy to meet the energy needs of a community for residential and small-scale commercial purposes in a localized way.

Here is another definition to make it clearer.

Vezzoli et al. defines DRE as small-scale energy generation units (structure), at or near the point of use, where the users are the producers—whether individuals, small businesses and/or local communities. These production units could be stand-alone or could be connected to nearby others through a network to share, i.e., to share the energy surplus. In the latter case, they become locally distributed energy networks, which may, in turn, be connected with nearby similar networks.