Sun Microsystems and HP have won awards from the US Environmental Protection Agency for their efforts to reduce carbon emissions.

HP picked up a SmartWay award for its transportation initiatives. The award recognises corporations that have made strides in reducing the carbon emissions of their surface transportation systems.

The company's efforts included switching to reusable plastic shipping pallets and slimming down packaging sizes.

Overall, HP estimates that it has cut some $2bn in fuel and maintenance costs and kept some six million tons of carbon dioxide out of the air.

"HP is committed to making meaningful reductions to its carbon footprint, not by simply offsetting it, but by improving our day-to-day operations," said Tony Prophet, HP senior vice president of worldwide supply chain operations.

"We will continue to aggressively explore ways to make our supply chain as efficient as possible with as little impact on the environment as possible."

Sun's recognition came in the form of a milestone achievement in the company's environmental plan.

The vendor had originally planned to cut its 2002 emissions level by over 20 per cent by 2012, but reached the milestone five years early, logging 2007 emissions estimates that were 23 per cent lower than in 2002.

Sun credits the achievement to a combination of consolidating servers and workstations, along with a remote worker programme which has cut office space and energy requirements at Sun's campuses.

The firm has now set a new goal to shave another 20 per cent off its energy consumption by 2015.