Sun Microsystems is an old hand when it comes to telework. The technology company has been growing its telecommuting ranks through its Open Work program for a decade, and today nearly 19,000 employees (56 per cent of Sun's population) work from home or in a flexible office.

With that experience comes plenty of knowledge -- about which jobs are best suited for teleworking, what technologies make it work, and how to train home-based employees and their managers, for example. But there was one question Sun couldn't answer until now: Does teleworking really save energy, or does it just transfer energy consumption and costs to employees?

"We sell servers that are improving the carbon footprint. Can we really say the same thing about how our employees are working? Are we really reducing the carbon footprint of our employees and saving money, or are we merely transferring costs from the company to the employees who work from home?" asks Kristi McGee, senior director for Sun's Open Work services group. "That's really the question we were trying to answer."

The company launched a study to measure how much energy is consumed while working in a Sun office, while working at home, and commuting to and from a Sun office. It outfitted study participants with P3 International's Kill A Watt meter, a kilowatt-hour monitor that taps into a power supply and measures electricity consumption at a workstation.

By comparing home and work energy use, the company found the rate at which office equipment consumed energy in a Sun office was twice that of home office equipment. Study participants averaged approximately 64 watts per hour at home compared with 130 watts per hour at a Sun office.

Employees who eliminated the commute to a Sun office also slashed their carbon footprints, McGee says. Sun found that commuting accounted for more than 98 per cent of each employee's work-related carbon footprint, while powering office equipment made up less than 1.7 per cent of a person's total work-related carbon emissions.

By eliminating commuting 2.5 days per week, an employee reduces energy used for work by the equivalent of 5,400 kilowatt hours each year.

"Not only did we find that the energy used by working in the office was about twice as much as what was used when working from home, which was a significant difference, but we also found a huge impact was the energy consumption used in the commute," McGee says.

In addition to benefiting the environment, employees benefit from reduced travel. The average employee can save more than US$1,700 per year in gasoline and vehicle wear and tear by working at home 2.5 days a week.

Metrics like these are helping drive greater interest in the Open Work program, McGee says. While the program has always been well received by employees, lately the primary attractors are shifting.

"There's a lot of support for the program from employees because of the flexibility that it offers, the work-life balance benefits that it provides. That has been the big attractor from an employee perspective over the long term. Now, it's the cost of gas that is coming to the fore," McGee says. "Employees are becoming more assertive about asking to work from home, or work flexibly, if they haven't already."