dJordan, like many other developing countries, depends heavily on imported oil. Solar water heating systems (SWHS) in Jordan have a high share among the renewable energy sources in the total mix of the energy consumed. In recent years, the demand for SWHS is decreasing because of the high initial investment of the system. Many people are starting to use gas geyser systems (GGS) to secure their daily hot water needs instead of the SWHS because the former has relatively a low initial investment. In this research, we compare the economic feasibility of a SWHS that has a built-in electric coil to provide for hot water needs during cold days with the economic feasibility of a GGS. The author prepared for this purpose a spreadsheet on Excel that incorporated the necessary formulas and parameters governing the economics of the two systems. The resulting spreadsheet facilitates the evaluation of the annual cost of each system for any assumed scenario of the values of the parameters. The use of Excel was extremely powerful because any change in any parameter was linked directly to a change in the graphs which was very useful for purposes of the sensitivity analysis of the parameters. The SWHS is more economical as long as electricity is used to heat water for less than 120 days which applies for the case of the weather conditions of Jordan. The optimal operation life for a SWHS in Jordan is 20 years and for a GGS is 7 years. The research presents some policies that promote increased utilization of SWHS. The presented methodology of economic analysis can be useful for the comparison of other competitive technical systems. (C) 2004 Published by Elsevier Ltd.