Economic Analysis of Residential Combined Solar-Heating and Hot-Water Systems

摘要

A brief description of a typical residential solar heating and hot water system and typical cost and performance information are presented. The monthly costs and savings of the typical system are discussed. The economic evaluation of solar residential systems is presented in increasing levels of complexity. Utilizing a typical system, the effective interest rate that the purchaser of a system would receive on money invested is shown for all regions of the country. The importance of numerous variables that can make a significant difference on the economics of the system is described so that it can be determined whether the typical system economics are compatible with the particular situation. Methods for calculating the payback period for any non-typical solar system are described. This calculated payback period is then shown to be related to the effective interest rate that the purchaser of the system would receive for a typical economic condition. A nomagraph is presented that performs this calculation. Finally, a method is presented to calculate the effective interest rate that the solar system would provide. It is shown how to develop the relationship between payback period and the effective interest rate for any economic scenario. (ERA citation 06:016629)