Your Always On Number Is More Interesting Than You Think

You’ve probably seen it in your Sense app. That Always On number sitting in your energy breakdown. Maybe you’ve glanced at it. Maybe you’ve wondered if it’s right. Maybe it changed one week and you couldn’t figure out why.

Most explainers will tell you what Always On is: the background energy your home uses 24/7, from devices that never fully power down. That part isn’t complicated.

What’s more interesting (and almost never explained) is how Sense actually calculates it, why it sometimes moves in ways that seem off, and what that tells you about your home that nothing else can.

That’s what this blog is all about.

The Gap Most Energy Monitors Can’t See

Sense detects devices by recognizing the electrical signatures they make when they switch on and off. Always On devices never make that move because they’re already on. Your router, your TV in standby, the controller board inside your refrigerator: constant, quiet draws with no transition for Sense to catch.

So Sense measures this differently. Rather than detecting events, it looks at the lowest points of your home’s energy use over a 24-48 hour window and uses those minimums to estimate your baseline (what your home draws just to exist).

For most homes, that’s around 250 watts. Across a year, that’s $165–$300 quietly leaving your account.

Why the Number Sometimes Looks Off

A few things can skew the calculation, and knowing about them can help you understand your home better.

Two devices hiding the floor. If two devices run almost constantly and tend to trade off (one cycling on as the other dips), your home’s usage never truly quiets down. Sense can’t find an accurate minimum, and your Always On reads higher than reality. If your number seems surprisingly large, look for devices running nearly continuously.

One unusual device disrupting the math. A Sense user traced erratic smart plug Always On readings to their heat pump’s defrost cycle; a brief, rhythmic dip that was just the right shape to throw off the calculation. If your number fluctuates with the season or time of day, a cycling appliance like a heat pump or pool pump may be why.

Smart plug double-counting. If many of your devices are on smart plugs, their Always On load can factor into both the plug and the top-level home calculation. Your total won’t be wrong, but your “Other” category may look smaller than expected.

Data gaps. Drop-outs in your usage data show up as zeros, which drag the calculation down over time. If your Always On suddenly drops for no apparent reason, check for a connectivity issue before assuming your home got more efficient.

Smart Plugs: From One Number to Real Answers

The whole-home Always On tells you the size of the problem. Smart plugs help you find the source.

When a device is on a Sense-compatible smart plug, Sense runs the same baseline calculation at the device level. Suddenly you’re not looking at one opaque number, you’re seeing which specific devices are responsible. Think about the gaming console that may be drawing 15W in standby. Or maybe the spare fridge in the garage running 24/7. That’s what moves you from awareness to action.

Three Ways to Start Lowering Your Always On

1. Sort your smart plug devices by Always On in the Sense app. Start with the highest draws.
2. Audit what runs but doesn’t need to. Secondary appliances (a spare fridge, an old desktop, a chest freezer) are often the biggest culprits and the easiest to justify unplugging.
3. Use a smart power strip on your entertainment setup. One switch cuts the TV, soundbar, streaming stick, and console together automatically.

Always On won’t always be a perfect number, but it gives you something genuinely new: a window into the energy your home uses just to exist.

In your Sense app: Tap the Always On bubble to see your baseline, your annual cost, and other helpful stats.