Ontario Electricity Policy - Supply Options

Supply Options

Electricity supplies can be classified as either distributed or centralized in nature. Whereas conventional, centralized generation involves few generation facilities connected via high-voltage transmission lines spanning long distances, distributed generation facilities are located close to the load—or in technical speak, on the customer side of the meter—although not necessarily restricted to local uses. In this scheme, distributed energy sources are more numerous and sufficiently smaller than central generating plants so as to allow interconnection at nearly any point in the electricity system.

Distributed generation—sometimes known as 'dispersed' or 'embedded' generation when referring to small-scale wind generation—generally describes only renewable electricity sources with capacities less than 10 MW. Technologies often associated with distributed generation include cogeneration—also known as combined heat and power (CHP) generation—as well as micro-turbines, fuel cells, and gas generators used for on-site or emergency backup power.

Renewables can also be considered distributed technologies, depending on their application. Typically, community wind farms, solar photovoltaic arrays, geothermal installations, and biomass-fuelled power facilities are typically sufficiently limited in their generation capacity that they qualify as distributed energy sources. Conversely, large hydropower plants and offshore wind parks, with substantial production capacities of 50–100 MW or more which feed into high-voltage transmission grids, cannot be considered distributed generation.