narrower concept coal Concept coal gasification Concept combined heat and power Concept combined heat and power (chp) Concept consumption Concept district heating Concept district heating provision Concept energy demand Concept energy storage Concept energy transportation Concept final storage Concept fuel Concept fuel oil Concept gas supply Concept heat balance Concept heat consumption Concept heat production Concept natural gas Concept natural gas supply Concept nuclear energy Concept petroleum Concept power generation Concept power requirement Concept power station construction Concept preparation plant Concept raw material supply Concept recycling Concept solar energy Concept solar power plant Concept tidal power Concept waste heat utilization Concept water power Concept wind power Concept