Life-Cycle Evaluation of Domestic Energy Systems

Abstract

Among the growing number of environmental issues, the global warming due to the increasing emission of greenhouse gases, such as carbon dioxide CO₂, is the most serious one. In order to reduce CO₂ emissions in energy use, it is necessary to reduce primary energy consumption, and to replace energy sources with alternatives that emit less CO₂.One option of such ideas is to replace fossil gas for water heating with electricity generated by nuclear power, hydraulic power, and other methods with low CO₂ emission. It is also important to use energy efficiently and to reduce waste heat. Co-generation system is one of the applications to be able to use waste heat from a generator as much as possible. The CO₂ heat pump water heaters, the polymer electrolyte fuel cells, and the micro gas turbines have high potential for domestic energy systems. In the present study, the life-cycle cost, the life-cycle consumption of primary energy and the life-cycle emission of CO₂ of these domestic energy systems are compare. The result shows that the CO₂ heat pump water heaters have an ability to reduce CO₂ emission by 10%, and the co-generation systems also have another ability to reduce primary energy consumption by 20%.