Power Consumption of IoT Devices

Power Consumption of IoT Devices

You may be wondering, “If I have all of these embedded devices plugged in, am I really saving any money on electricity?” This is a valid question! Let’s look at some common IoT devices and how much power they use.

ESP32: The ESP32 you used in Lesson 10 can be customized a hundred different ways. The ESP32 has a few different modes: Active, light sleep, moderate sleep, and deep sleep. In active mode, the device will use about 75mA of power. Since that is running at 5 volts of power, that is 0.375 watts. This is not much in the grand scheme of a household’s power. You need about 30 ESP32s running at the same time to equal the amount of power a single LED is running! ESP32s can go into other power-saving modes, such as deep sleep, to draw as little as 40μA!

Smart Home Assistant: Smart home voice assistants tend to use a watt or two in standby mode (until you say the “wake word”) and, when on, they tend to use under 10 watts of power.

Smart Thermostat: A smart thermostat uses anywhere from 3-9 watts of power as it controls the HVAC system. When not running those systems, the thermostat goes to a lower power state. Many smart thermostats have a motion sensor to detect if a person is in front of the thermostat. These sensors can turn on the thermostat display, which does increase the power draw. Then, the screen goes dark when a person moves away.

Overall, these smart additions do take energy to run, but the energy savings can be huge. Some estimates suggest that smart lighting can result in savings on lighting costs of 35-70%!