A survey of employees' home and workplace energy use has revealed that office equipment eats up energy at twice the rate of home equipment.

The in-depth study was conducted by Sun Microsystems on a selection of its own employees, who were equipped with a kilowatt-hour monitor that measures electricity consumption.

Participants averaged a power consumption of 64 watts per hour at home, compared with 130 watts per hour at a Sun Microsystems office.

The results suggest that cutting down commuting by 2.5 days per week could reduce an employee's energy consumption by the equivalent of 5,400 kilowatt hours a year.

Employees who cut out their daily journey to a Sun office also reduced their carbon footprints. Commuting accounted for more than 98 per cent of employee work-related carbon footprints.

"We found that the energy used by working in the office was about twice as much as that used when working from home, which was a significant difference," said Kristi McGee, senior director for Sun's Open Work services group.

"But we also found that the energy consumption used in the commute to work had a huge impact."

Sun has long been a pioneer in promoting the benefits of teleworking through its Open Work programme. More than half of its workforce regularly work from home or in one of the company's flexible offices.

The vendor operates a system known as 'hoteling', where employees reserve office space at any Sun location and log-on to the resident Sun Ray machine when they choose to work on-site.