Many technology students--and especially those interested in environmental and energy issues--can benefit from learning about power ratings and the energy usage of electrical systems like the electrical equipment and appliances found in most homes. Students enrolled in electronics and construction technology courses learn to determine the power rating (wattage) and energy usage (kilowatt hours) of such electrical systems. This knowledge is valuable in estimating the operational cost of new equipment and in determining if an appliance is functioning properly. It also gives students a better understanding of the relative value of electrical appliances and a greater appreciation of the value of the "electric-energy" dollar. And it increases students' overall understanding of electricity fundamentals. This article describes an activity that enhances students' understanding of energy usage and also provides a valuable service to members of the community. (Contains 2 figures and 2 photos.)