I work with Non Intrusive Load Monitoring A consumer who wants to economize on phone has many details in the bill that allows manage his consumption. In contrast, the electricity bill has just two information, the amount of kilowatt-hours and the total price. Although he would like to know how to expend less kilowatt-hours, this number does not have practical meaning for him. If he just decides to avoid use the appliances, it could be inefficient and implies an unnecessary loss of comfort. A more reliable approach is put a meter in each appliance, check the individual consumption and make better decision about habits of use and retrofit of some appliances. However, this approach is very expensive and the economy reached could not be able to pay back by the investment in the meters. But in 1982, G. W. Hart started to study a new approach who can provide good information to the consumer by a low price. Hart was monitoring the load curve from a neighborhood when he realized that he could “read” the plots by eye and tell what was happening in the monitored house. After that he figure out that he could formalize the steps to write a computer program, which does a similar analysis. In that way was started the study in Non-Intrusive Load Monitoring (NILM), the name non-intrusive cames from the fact that is not necessary get into to the house to know which appliances are running. The approach to put a sensor in ever appliance is called of Intrusive Load Monitoring (ILM) because the neediness of access to the appliances.