Consumers range from residential buyers to huge industrial consumers mining the oil sands, operating pipelines and milling forest products. On the supply side, generators range from wind farms east of Crowsnest Pass to huge coal-fired plants near Edmonton. The diversity of Alberta's electricity supply has increased substantially. To a large extent because of deregulation, the province has more technology, fuels, locations, ownership, and maintenance diversity than in the past. The system's reliability, its cost structure and Alberta's collective exposure to risk are now met by a complex system based on diverse power sources, mainly coal and natural gas, with some wind and hydroelectric energy sources.