An interesting study by Opower has found that Yahoo email users consume 11 percent more energy per year than Gmail users. The survey of 2.8 million American households in Opower's database showed that Yahoo users spend an average of $110 more on energy bills each year than their Gmail counterparts, based on the email address of the person who manages the electricity bill.
Eleven percent is a pretty significant difference -- an average of 939 more kWh per year by the Yahoo households, or about a whole extra month's worth of energy use. To put that in perspective, the difference in energy use by 1 million Yahoo users compared to 1 million Gmail users is equal to the entire annual energy consumption of Barbados.
Opower says, "It’s as if, relative to the average Yahoo household, the average Gmailer is strictly hang-drying their laundry, forgoing high-definition TV, and hand-washing their dishes with cold water for a year."
Previous studies by Experian and Hunch.com found that Yahoo users tend to live in larger homes in suburban areas, while Gmail users more often live in cities, but even after controlling for home size, the typical YahooMail household uses 12% more electricity per square foot of living space than the typical Gmail household.
So what could be responsible for this energy use gap? Opower explains the key differences in Yahoo and Gmail users' lifestyles that likely contribute to energy consumption:
Hunch.com and Experian have found that Gmailers are more likely to be younger, single people. Credit Karma found the average Gmailer’s age to be 34, while the average Yahoo user clocked in at age 38. Being young and single means going out more; less time at home – and fewer occupants – means less electricity usage.
By contrast, Yahoo users are more likely to be in relationships and have children. Additionally, Hunch found that Gmail users are more likely to be active travelers (having journeyed to 5 or more countries), and so might be away from home more often.
Our own data also suggest that Gmail users may have a greater interest in energy-efficiency. Among the approximately 10 million US households that have access to utility web-based energy-efficiency advice tools that Opower manages, Gmail users are 30% more likely than Yahoo users to sign up for an in-depth analysis of how they can reduce their energy usage.
So, it really comes down to the demographics -- Gmail users skewing younger and city-centered, while Yahoo skewing older, family-oriented and suburban -- and how those groups of people tend to consume energy.
Maybe Yahoo users could use one of Opower's energy management services, or perhaps their social energy app with Facebook to help shave off some of those kWh.