TECH BEAT: Using a Smartphone? Find Out Why You're Already Energy Efficient.

As the world’s interest in the iPhone 5 mushroomed in the weeks leading up to its launch, analysts at Opower – whose software helps homeowners make energy-efficient choices – wanted to see how smartphones measure up with other consumer electronics in energy use.

“Smartphones emerged as a clear winner in terms of energy efficiency compared to the devices we have historically used to consume entertainment and communicate with each other,” said Opower’s Barry Fischer, who wrote the in-depth blog post on the subject.

Charging an iPhone 5 Costs Less Than $0.50/Year

Opower used a Watts Up Pro Electricity Consumption Meter to measure how much energy the iPhone 5 uses. Turns out, it’s not that much. Charging an iPhone 5 from zero power to full power once a day for a year only costs $0.41. That’s per year – not per day.

To make sure the world’s fastest-selling iPhone wasn’t an outlier, Opower's analysts tested the world’s fastest-selling Android: the Samsung Galaxy S III. They found that the Galaxy’s energy costs are just pennies more, at $0.53 per year.

Two Energy-Efficient Thumbs Up for the Hand Computer

While fifty cents per year is cheap on the individual level, millions of people are using that energy. The iPhone 5 sold 7 million units by its third day on the market, and it is expected to reach 170 million people in the next year. Meanwhile, 20 million people already use the Galaxy S III.

Here's the kicker: The time we spend on our smartphones and tablets for sending email, surfing the Internet, playing games, and watching videos is time that we’re not doing those tasks on more energy-intensive electronics like laptops, PCs, or TVs with video game consoles and set-top boxes.

“The take-home message is that a day spent Facebooking on a smartphone is a much more efficient day than one on your computer,” Fischer told the Alliance. Just check out this graph:


Households Use Less Energy Today, Despite All Those Extra Gadgets

If you think that we’re actually using more energy overall because of the many more devices nowadays, consider this: Per-household energy use in 2005 was actually a bit lower than in 1978. That’s despite a marked rise in consumer electronics: In 1978, the average household had one TV, and 1% of all households had a computer; in 2009, the average household had 2.5 TVs, and 76% had a computer. But per-household energy use flatlined in that time period, mostly due to better home insulation and more energy-efficient appliances. 

“That doesn’t mean we’re off the hook,” Fischer notes. “There's still a need and opportunity to reduce energy consumption further to get where we want to be.”

One way might just be to unplug all those vampirish, energy-sucking electronics while they’re not in use. And give yourself a pat on the back every time you send email between your hands instead of on your lap or at your desk.

More on Smartphone Energy Use

Read Barry Fischer’s analysis in Outlier, a blog that uses Opower's energy data to explore trends in how people are consuming energy at home.