Electronics for Students and Engineers: Monitoring Electrical Power consumption

Power Monitoring for Household

Almost most of the household in India consume electricity, we all know that their is a electricity meter which keeps track of the consumption and once in a month the meter reader prints the bill for payment and we need to pay before due date.

We also except that day by day we are more dependent on electricity, to name a few things following are the equipment's which we will use

Television [100W typical] - some time we do not bother to switch off for that short interval of time
Geyser [2000W typical] - we leave it ON till the time we are ready for bath
Chargers [10W typical] - most of the time hooked up, how if they turn OFF after a charge full
LED Lights [each 20W typical] - how if they turned ON if we are present in a room
Ceiling FAN [60W typical] - how if they turn ON if you are present and Temperature set
Desktop / Laptop [100W typical] - Any ways will hibernate when you don't us it for some time
Refrigerator [100W typical] - need to run always, any idea how many units you consume?
Water purifiers - always ON and motor works when water level low
Vacuum cleaners - used only during vacuuming
Washing machine - Lightly used, may be once or twice a week
water pump - will turn ON and OFF with water level sensor.

If we look at all the devices we use we may get thoughts about using sensors, power monitoring , automating home.

Automating home is really an interesting idea, automation is done using sensors and electrical equipment's. example use

Motion sensor to sense your presence and turn ON / OFF the light
Use LDR to detect and turn ON the light
Use water level sensor to check over head water level
Turn OFF your TV if you are not watching
Turn OFF all light, FAN and other devices when you are not in home

All automation if works round the clock is good, but most of the time you need a feedback if all devices are OFF, because your automation sometimes may not work because of various reasons - may be the device is dependent on the cloud, power supply failed and resumed which made some equipment ON

So if you have a means of measuring power this give an estimate of how much power is consumed currently and also you can see the log and try to make better decision in buying products. Monitoring power can be dome in various ways

Local monitoring on a display
Local monitoring on local wi-fi network
Monitoring using a cloud service

An Example power Monitoring using SONOFF Mini R3 device

I use a SONOFF (from https://www.sonoff.in/) to monitor the power. The good thing is that this device can be integrated with Home assistant Automation OS which runs on Raspberry pi.