Addis Ababa Bottle & Glass Share Company purchases furnace oil and electricity from NationalrnOil Company (NOC) and Ethiopia Electric Power Corporation respectively to satisfy its primaryrnenergy demand. The prices of a liter of furnace oil and a kWh of electricity are 9.49Birr andrn0.5778 Birr respectively.rnThe objective of the thesis is to suggest cost effective measures to improve the efficiency ofrnenergy use. The scope is to identify energy conservation opportunities to reduce energy costs andrnprepare an energy & documentation to implement cost effective energy utilization changes.rnThe methods employed to achieve the objectives of the research are: Literature review,rnPreliminary data collection of the company, Inspection of company energy consuming systemsrnand equipment, Perform desktop analysis, Identify feasible Energy Conservation Opportunitiesrn(ECOs), Perform technical feasibility of the identified (ECOs), Perform economic analysis of thernidentified (ECOs), Prepare list of recommended energy conservation measures (ECOs) &rnPrepare action plan.rnTo evaluate the performance analysis of these major energy consuming systems, different datarnwere collected by using portable instruments, the instruments installed on major energy systems,rnnameplate and referring to company log sheet and record book. The instruments are: PortablernCombustion Analyzer (PCA) analyze combustion air, Infrared and dual K contact thermometerrnmeasure the surface temperature, Tape meter measure the length of the object & Vernier'srncalliper measure the internal pipe diameter.rnUsing these data pre-energy audit analyses on heating value of furnace oil, combustion propertyrnof the furnace and some of the results obtained including NCV of furnace oil is 39262.6kJ/kg &rnthe excess air in the furnace is 136% .rnTo conclude that using standard methods the energy balance was conducted to determine the firstrnlaw efficiency of the furnace and the corresponding energy Sankey diagram. The first lowrnefficiency of the furnace on heat balance method is found to be 42%.