New Delhi, Nov. 21 -- Smart homes sell a simple promise - convenience. A quick voice command dims the lights, your water heater kicks in before you reach home, and the coffee machine starts its morning ritual before you're even awake. It all feels efficient and futuristic, right? But what rarely gets talked about is the other side of that comfort - the slow and steady rise in your electricity bill as more connected devices sneak their way into your rooms.

Think about how many devices in your home stay "ready" at all times. A smart plug by itself barely uses anything but once you add a handful in each room - one for the lamp, one for the purifier, and one for the TV setup, what you get is a small army of gadgets sipping electricity day an...