HP and Intel have teamed up to unveil a line of energy-conscious workstations.

The companies showed off two new PCs, the DC 5800 and the DC 7800, at a special event in San Francisco on Tuesday.

The machines are designed for maximum power efficiency, and offer more efficient power supplies and software to better manage auto-shutdowns.

A notable feature on the DC 7800 is an optional 16GB SanDisk solid-state hard disk. The drive will add $300 to the cost, but offers faster boot and load times and improved power efficiency.

Kirk Godkin, senior product manager at HP, told reporters that he expects solid-state drives to become a mainstay of the company's PC offerings by 2010, when chip prices fall sufficiently to make the drives practical.

The new PCs also feature Intel processors with vPro remote management tools. The processors will work with Surveyor, a tool which allows network administrators to gauge power consumption on large networks.

HP plans to have a version of Surveyor for small to medium sized businesses within 45 days.

The new PCs form part of a larger environmental effort by the two companies. Other elements include more efficient data centres, better recycling initiatives and new building materials.

The recycling programme has been hampered, however, particularly with government regulations.

Carl Eckersley, of HP's Personal Systems Group, told reporters that electronic waste and recycling efforts have been slowed by different laws throughout the US.

"I would love to see the federal government step in," he said. "Complying with 50 state laws is a lot harder than complying with one federal law."

Eckersley pointed to the recent WEEE laws in Europe as an example of how electronic waste could be regulated. "The Europeans are as advanced as anybody, " he said.