In much of the United States, people take daylight saving time for granted. We'll turn our clocks forward an hour in the spring and back again in the fall. But does the time change actually save energy?
The concept of daylight saving time has been around for hundreds of years. It's often traced back to Benjamin Franklin, who jokingly proposed earlier wake-up times as a way for people to save money on candles in a 1784 essay -- but the founding father wasn't actually serious, according to the Franklin Institute.
Moving the clocks forward an hour during the summer, when daylight is naturally longer, was first widely instituted globally during World War I as a way to save energy. The idea was that taking an hour of daylight from the morning and adding it to the evening would mean less electricity used to light homes and businesses at night.
The practice became US law with the Standard Time Act of 1966, and today, only Arizona, Hawaii and several US territories don't observe daylight saving time. In 2023, US Sen. Marco Rubio reintroduced a bill that would have made daylight time permanent, but it was never brought to a vote in the House of Representatives.
Over the past 20 years or so, the conventional wisdom that daylight saving time cuts down on energy use has come into question with new research on its benefits and drawbacks. Plus, daylight saving time has been shown to negatively affect mental and physical health as people struggle to adjust to the sudden change. Here's what to know about daylight saving time and whether it really pays to set your clocks back in the fall.
When daylight saving time was first widely practiced more than a century ago, adding an hour of daylight to each evening may have helped with wartime energy conservation. But today, the way people consume energy has changed, said Michael Lotfy Gierges, president of home and distribution business at digital automation and energy management company Schneider Electric.
"Daylight saving time still does a good job, but the population has increased and the profile of energy consumption has increased," he said, citing a French statistic that showed energy savings dropping by nearly two-thirds from 1,200 gigawatts saved in 1996 to 440 gigawatts in 2019. "This shows that energy usage in homes and buildings has changed."
Research indicates that energy reductions from daylight saving time are minimal at best. A 2008 study in Indiana showed that while people may have relied more on sunlight than electric light, they used more air conditioning during longer days, while a 2017 study found that springing forward and falling back only saved 0.34% in terms of energy use, according to the New York Times.
Energy savings from electric lighting
Due to a few different factors, lighting has become a much smaller portion of residential home energy use in recent years. One reason is the development and popularity of LED lighting. An LED light bulb uses only about 16% of the energy as an incandescent bulb of the same wattage.
Changing light bulbs over to LEDs means significant energy savings overall. However, the greater efficiency of these bulbs means that savings you may have seen by changing your lighting habits during daylight saving time is likely to be much less than with incandescent bulbs.
In addition to using more efficient light bulbs, we're using and charging more electronic devices. Many more people work from home now than in the past, and the growing popularity of EVs means greater residential energy usage as people charge their cars at home. Plus, extreme weather translates to hotter summers and colder winters, which increases the need for heating and cooling.
"A lot of people think that lighting is the largest percentage of residential energy use, but lighting, depending on the size and location of the home, represents anywhere from 3 to 7%," Gierges said. "The vast majority, 50 to 70%, is from climate control in your home."
Other ways to save money on energy
Rather than relying on daylight saving time to reduce your electric bill, Gierges recommends taking steps to make your home more energy efficient in other ways.
For example, zonal heating and cooling that allows you to control the temperature in each room, whether manually or automatically using a smart thermostat, will cut down on energy use. Using energy-efficient window coverings like shutters, drapes or awnings helps keep homes cooler in the summer and warmer in the winter, too.
Smart thermostats can also be programmed to heat and cool during off-peak hours when electricity rates are cheaper -- which helps flatten the duck curve while lowering your bills. Plus, your smart thermostat may be able to connect to a virtual power plant, a program that offers rewards in exchange for the ability to make tiny adjustments to your thermostat to manage energy demand.
In addition to cutting down on energy use during times when demand is high -- which is important for managing the country's aging electrical grids -- "these changes can put money back in your pocket right away," Gierges said.
What to do because of daylight saving time?
Even though daylight saving time might not actually help you save energy, this semi-annual ritual is still in place. Until federal law changes, you might as well take care of some other important household tasks when it's time to fall back on Nov. 3, 2024.
- Replace smoke detector batteries: Make it a habit to check and replace batteries in your home's smoke detectors when you change your clocks twice a year.
- Change HVAC filters: Regular maintenance is one of the best ways to extend the life of your HVAC system. Swap out or clean filters to minimize costly repairs down the road.
- Clean your dryer vent: Help prevent fires and keep your dryer running efficiently by clearing lint out of the tube that goes from the appliance to the outdoors.
- Rotate your mattress: Rotating or flipping your mattress helps reduce indentations, extending its life and giving you a more comfortable night's sleep.
- Check emergency kits: If you keep an emergency kit with items like nonperishable food, water, flashlights and other battery-powered devices, daylight saving time is a great reminder to check that your supplies are up to date.