Fonte: ANEEL
Knowing how to compute the consumption of the appliances can help reduce the value of the energy bill, and also prevent home appliances from wearing out. Check below for a list of equipment that most consume energy in homes and how to track and calculate their consumption.

Electric Shower
The power of the shower varies with the position of the key. It can vary from 4500 to 6000 watts in winter mode (hot) or from 2100 to 3500 watts in summer mode (warm). Consumption per hour (60 minutes) of usage is 4.50 to 6.0 kWh (kilowatt hours) in the winter position and from 2.10 to 3.50 kWh in the summer position. In order to calculate the consumption of your shower, just use the following rule: 

Consumption = (power in watt/1000) x (time) number of hours = total in KWh 

Thus, if the power is 5,500 W and the use for a specified period is 2 hours, total consumption expressed in kWh will be 5.500w/1000 = X 2 = 11 kWh.

Air Conditioning
An air conditioner cools and ventilates. The table below shows the consumption considering half the time used for cooling and the other half for ventilation. In ventilation mode power ranges from 100 to 200 watts.