Lights Out! This $15 Device Could Actually Save You 30% on Your Energy Bill

occupancy sensor
Photo from

Much of the country is in the clutches of freezing winter weather right now. So as temperatures go down, thermostats go up.

Even down here in allegedly balmy Florida, I’ve been cranking my heat to avoid becoming a human popsicle. I realize my house becomes less energy efficient with every degree I bump up my thermostat — but I get cranky when I’m cold, and nobody’s got time for that.

I recently decided to look for ways to assuage my guilt and offset the energy I use to heat my home by finding other ways to be fiscally and environmentally responsible. The U.S. Department of Energy gave me a great idea.

The DOE claims I can save as much as 30% on wasted electricity by installing occupancy sensors in the rooms my family uses most.

So I can save 30% and still keep my fingers from turning blue while lounging in my living room? Yes, please!

What the Heck is an Occupancy Sensor?

I wasn’t particularly familiar with occupancy sensors or how effective they are, so I did a little digging.

It turns out these inexpensive devices are actually pretty neat.

Most residential occupancy sensors are designed to replace existing light switches. They don’t require an expensive electrician visit because they’re super easy to install.

They’re typically motion-activated, constantly on red alert for movement of the human variety. If the room is empty for more than a few minutes, the lights automatically switch off.

Since the sensors are located in the same spot as traditional light switches, they won’t pick up motion from animals unless you happen to have an alpaca or some other really tall pet (and if you do, please invite me over).

Yeah, But Do Occupancy Sensors Really Save Money?

I did a little research into just how efficient these little gadgets are and whether they live up to the hype.

It turns out they do.

If reading energy reports is your jam, here are a few to check out. If not, I did the research so you don’t have to.

  • This Environmental Protection Agency study found businesses that use sensors average 60% energy savings. Granted, this report focuses on office buildings, but it does support DOE’s 30% residential savings claim. 
  • If you like visuals, here’s a joint study summary between two U.S. and Canadian energy agencies with a cool graph showing how much you can save depending on the type of light bulb attached to the sensor. 
  • Check out the full joint agency report for an in-depth look at lighting wastage estimates, average energy savings per room type and other delightfully nerdy data.

Where Can I Buy Energy-Efficient Occupancy Sensors?

You can find occupancy sensors at just about any big box home improvement store and at some chain hardware stores.

If you don’t want to bundle up and leave your house, hit up Amazon for a wide variety of sensors, starting at around 14 bucks. If you want to wire up a bunch of rooms, this 6-pack will run you $65, which works out to just about $10 per sensor.

Occupancy sensors are a great way to offset the cost of setting your thermostat higher during the winter, but they’ll help keep your home more energy efficient all year. How cool… er, hot is that?

Your turn: Do you have occupancy sensors in your home? How much money have they helped you save on energy costs?

Lisa McGreevy is a Staff Writer with The Penny Hoarder. She’s happiest when it’s at least 85 degrees, so this winter weather can suck it.