Comparative life-cycle cost and GHG emission analysis of five different water heating systems for residential buildings in Australia

In this paper, five different types of water heating systems namely electric instantaneous, electric storage, natural gas instantaneous, natural gas storage, and heat pump are studied for Australian conditions. The study is carried out for understanding the life cycle cost of each system under similar water demand conditions. The focus is made on life-cycle cost (LCC) that include the running costs on an annual basis, and total running cost for the system life, maintenance cost; and greenhouse gas (GHG) emissions. The observations reveal that five systems had major differences in the upfront cost, running cost, and life-cycle cost, and GHG emissions. The observed LCC and GHG emissions for electric instantaneous, electric storage, natural gas instantaneous, natural gas storage, and heat pump are 9005 AU$, 12,724 AU$, 6955 AU$, 7479 AU$, and 8098 AU$, and 1862 tons of CO₂, 2306 tons of CO₂, 851 tons of CO₂, 917 tons of CO₂, and 842 tons of CO₂ respectively.