Summer 2013

Close to Home | Smart Tools for Saving Energy

Some of the most effective strategies for saving energy—turning off or unplugging appliances when they are not needed, turning down the thermostat—should also be the easiest. But we sometimes forget, or fail to schedule, these tasks. Fortunately a variety of gadgets can do the remembering for us.

Light Switches

Programmable thermostats are just one of many "smart" gadgets available to help reduce household energy use.
Photo: ©iStockphoto

To help reduce lighting-related electricity use (about 13 percent of total household consumption, according to the U.S. Department of Energy), consider replacing traditional light switches with sensors. Sensor-based light switches use infrared or ultrasonic technology (or both) to detect heat and motion. Occupancy sensors are the most common; they can be used in almost any space and automatically turn lights on when motion is detected; vacancy sensors are best for spaces like bathrooms and hallways where we do not spend most of our time, and are turned on manually. Both types turn lights off when no motion has been detected for a set amount of time.

Most models allow you to adjust sensitivity (to avoid accidental activation) and duration. Some save additional energy by preventing lights from being turned on if there is sufficient ambient light. Sensor-based switches range from $20 to $40 or more depending on features; you can recoup these costs fastest by using sensors in little-used areas where you may inadvertently leave the lights on for long periods.

Power Strips

Unlike the power strips that most people use for groups of electronic devices like their computer, monitor, modem, and printer, “smart” power strips automatically cut power to these devices when they go into standby mode (i.e., when they are technically “off” but continuing to draw electricity). According to the Department of Energy, standby (also known as “vampire” or “phantom”) power accounts for about 8 percent of total household consumption.


Most smart strips have one or more “always-on” outlets for devices such as cordless phones and digital video recorders, and some have adjustable sensitivity to detect standby power levels that are not much different than full power. Smart strips are more expensive than regular models (approximately $20 to $40 compared with $5 to $15) but can quickly pay for themselves through reduced electricity costs.

Today, even the most basic programmable thermostats (which cost as little as $20) offer a high degree of customization, including multiple settings per day and multiple programs per week. This allows your heat and air conditioning—which together account for more than half of home energy use—to be automatically turned up or down based on your specific schedule.

If you have an unpredictable schedule, consider a model that can be controlled via the Internet, or a “learning” thermostat (like the one from Nest*) that employs sensors to detect whether you are at home or away and creates a heating and cooling schedule based on your habits. These “smart” thermostats are more expensive—around $100 to $150 for an Internet-connected model or $175 to $250 for the Nest—but have the potential for big energy savings in the long run. Recent research suggests that for each degree you turn down your thermostat over an eight-hour period, you can reduce your heating costs by 1 percent or more.

* Listed for informational purposes only and does not imply endorsement.

Also in this issue of Earthwise:


Why are tar sands a bad fuel source?