November 04, 2010, 10:09 PM — Where do you start when your company demands a 20% reduction in its carbon footprint? At PricewaterhouseCoopers, it wasn't enough to just pursue high-profile projects, such as building the LEED Gold-certified data center that came online in January.
It was just as important to come up with grass-roots ideas and make smaller companywide changes, such as rolling out multifunction printers configured with two-sided printing as the default, using longer-lasting print cartridges, promoting videoconferences over in-person meetings and providing a carbon calculator that employees can use to see how their offices stack up against those of their peers -- a tool that helped reduce office energy use by 18%.
"We've hit a lot of the low-hanging fruit," says John Regan, director of data center services. "Now it's about those incremental changes." Those changes, big and small, have added up: In September, PwC achieved its goal, just two years after making the pledge -- and two years ahead of schedule.
PwC's new data center in Georgia has made a significant contribution, reducing power consumption by 20 million kilowatt-hours and cutting operating costs by $2 million -- a 40% savings. The firm realized those savings by virtualizing 2,500 servers, using more-efficient equipment and moving to an optimized hot-aisle/cold-aisle design. PwC also distributes power at 575 volts AC instead of the industry standard 480 (which saved on copper and eliminated some uninterruptible power supply equipment).
KC Mares, president of data center design firm Megawatt Consulting, has installed 575-volt distribution systems, and he says the primary benefit is upfront savings. "It saves on capital costs, but operating cost savings are generally in the area of 1% of less," says Mares.
The new design allowed PwC to raise the temperature of chilled-water feeds into the air conditioning system by 10 degrees, which has translated into an immediate energy savings of 15%. In addition, air-side and water-side economizers drop the mechanical energy consumption of computer-room air conditioning systems by 75% when active, says Bill Panian, PwC's data center facilities manager. In February, the chillers ran just 6% of the time, helping the firm achieve a savings of 100,000 kwh -- an unexpectedly good result.
A monitor in the lobby of the data center building features a live feed that shows energy consumption and the performance of the air-side economizer in real time. Panian says he expects technology advances to allow chilled-water temperatures to continue to rise over time, and that should bring even greater efficiencies.