Home Motion Sensors: Energy Efficiency, Convenience, and More
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Author
Andrew Blok
Electrification and Solar Writer and Editor
The smart home is often marketed as a luxury, but its most practical application is purely functional: taking things off your plate. Motion sensors, once relegated to outdoor security lights, are now used throughout homes and, beyond convenience, can boost a home’s energy-efficiency. When integrated across lighting, climate control, and even water systems, they can help cut down on vampire energy losses and help shave kilowatt-hours off your electric bill.
Here’s how motion sensors can impact a home’s primary energy drains.
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Eliminating lighting waste
Lighting accounts for approximately 10% of average household electricity use, according to the Department of Energy. Motion sensors help cut down on the waste from leaving lights on in an empty room.
- Measured savings: Estimated savings from deploying motion sensor lights can cut lighting energy consumption by anywhere from 30% to 60% in high or medium traffic areas up to 90% in places a light bulb may be left on and forgotten for long periods of time, like an attic.
- Outdoor uses: Switching from always-on outdoor lights to those that turn on when motion is detected cuts down on the time those lights are consuming energy for no real safety or convenience benefit.
- Efficient sensors: Modern sensors will consume some standby power, but are highly efficient in standby mode. For many uses, the energy saved by turning off the bulb far outweighs this minimal draw.
Cutting down on HVAC waste
Heating and cooling represent the largest energy expense in most homes (close to 50% for most homes, according to the US Energy Information Administration). While a manual thermostat relies on your memory, motion-integrated smart thermostats use real-time data.
When a connected motion sensor detects an empty room or home, it can automatically set the thermostat back to a more energy-efficient setting.
- Automated setbacks: Research from the National Laboratory of the Rockies (then called the National Renewable Energy Laboratory) indicates that occupancy-based HVAC controls can reduce heating and cooling energy consumption by up to 20%, depending largely on how far back the thermostat is set when a room is unoccupied, and how often a room is unoccupied.
- Zoning efficiency: By using remote motion sensors in individual rooms, systems can prioritize comfort where people actually are. An ASHRAE study demonstrated that sensing occupancy across multiple rooms could achieve annual electricity savings of more than 35% by reducing HVAC use in empty spaces.
Water heating: on-demand efficiency
Heating water is the second-largest energy expense in many homes. If your home has a recirculation pump, it may run on a timer or continuously, wasting energy to keep water hot in the pipes. Connecting it to a motion sensor allows it to run only when someone enters the bathroom, cutting down its energy consumption while keeping hot water ready at hand.
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Where sensors offer the highest ROI
The ROI of a motion sensor depends largely on the occupancy pattern of the room.
| High-ROI areas | Typical usage | Why it works |
|---|---|---|
| Garages & basements | Intermittent | Lights are frequently left on for hours by mistake. |
| Bathrooms & closets | Short-duration | Ideal for hands-free convenience and short-duration lighting needs. |
| Hallways | Transient | Provides safety lighting exactly when needed. |
| Unused bedrooms | Variable | Allows HVAC systems to drift to energy-saving temperatures. |
Vacancy vs. occupancy sensors
Vacancy and occupancy sensors sound like two words for the same thing, but there’s a key distinction. Occupancy sensors turn on automatically when they sense motion, and turn off when they sense the room is vacant. Vacancy sensors turn off under the same conditions, but require you to manually turn the device on.
Vacancy sensors can help avoid accidental triggers that turn devices on when they don’t need to be: a pet walks across the room or you enter an area just to grab something, but don’t need the lights to turn on.
Are motion sensors worth it?
According to energy efficiency research, motion sensors can help reduce energy consumption. Depending on their application, some motion sensors can pay for themselves in just one year. Whether or not a motion sensor will pay for itself at your home depends on your cost of energy and how often you forget to turn off the lights or adjust your thermostat when leaving the house for eight or more hours. Motion sensors can also bolster benefits like convenience and security, which may be worth it regardless of cost.
Curious about how you can save energy in your home? Download the Palmetto app to learn more and start earning rewards toward discounts on energy saving devices, including motion sensors. Or reach out for a home solar panels savings estimate and start generating your own electricity.
Frequently asked questions
Can motion sensors save you money?
In some cases, yes. When motion sensors cut down on electricity wasted by leaving lights on or forgetting to adjust a thermostat when leaving the house, they can shave down energy bills.
Do motion sensors consume more energy than they save?
It depends on the application, but modern motion sensors use very little standby energy in general.
