Small Scale RES
Renewable energy systems are usually founded on a small-scale, decentralized paradigm that is inherently conducive to many issues related to electricity distribution, cogeneration, environmental, and capital cost. These systems can have dramatically reduced as well as widely dispersed environmental impacts, rather than larger, more centralized impacts that in some cases are serious contributors to ambient air pollution, acid rain, and global climate change. The term distributed generation (DG) is used to describe the integration of small-scale power generation technologies (of which a significant part are renewables) into a network located close to the loads served.
More specifically, DG is the application of small generators from 10 to 10,000 kW scattered throughout a power system and either interacting with the grid or providing power to isolated sites. Dispersed generation is sometimes used as an interchangeable term, but it should be used for very small generation units, in the range 1 to 100kW, sized to serve individual households or small businesses. DG technologies may be renewable (e.g., photovoltaic, thermal, wind, geothermal, and ocean-source systems) or nonrenewable (e.g., internal combustion engines, combined cycle engines, combustion turbines, microturbines, and fuel cells). Household and rural users are concerned with the deployment of DG because of the overwhelming investments required to connect to a distant grid. DG technologies can improve power quality, boost system reliability, reduce energy costs, and defray utility capital investment.