Simply shutting down workstations after an 8-hour workday, when possible, can yield significant energy cost savings and also produces environmental benefits, according to a study published in the November issue of the Journal of the American College of Radiology.
Prasanth M. Prasanna, MD, of the University of Maryland Medical Center in Baltimore, and colleagues wanted to investigate methods of reducing energy consumption in radiology departments given the high-tech nature and substantial electricity needs of equipment in the industry.
“Clearly, it would not be possible to turn off all computers or PACS workstations in a hospital, given the 24/7 nature of the work environment,” wrote the authors. “However, shutting down machines that are not in critical areas or in use for overnight call can still make a large difference.”
The researchers monitored electricity usage during both active and standby states, with cost per kilowatt-hour (kWh) calculated at $0.11, not including taxes or fees.
A single monitor, left on 24/7 for a year, would consume between 49.5 and 1,399.84 kWh at a cost of $5.45 to $153.98. A workstation left on for the same period would use between 455.65 and 2,358.72 kWh at a cost of $59.91 to $259.46. Based on these energy usage rates, all workstations and monitors at the researchers’ facility would use approximately 137,759.54 kWh per year at an aggregate cost of $15,153.55.
Should all equipment be shut down after an 8-hour workday, the department would save 83,866.6 kWh and $9,225.33, according to the authors.
“With the increasing necessity of cost savings and energy reduction, this small and simple step, implemented hospital-wide, will lead to much larger cost savings across institutions,” wrote the authors.
In addition to the impact on a facility’s bottom line, an effort to shut down workstations when they aren’t needed can greatly reduce the production of greenhouse gases. According to background information in the study, electricity production accounts for 40 percent of carbon dioxide, 68 percent of sulfur dioxide and 22 percent of nitrogen oxide emissions in the U.S.
“Every 10,000 kWh saved is equivalent to removing 1.4 cars from the road, saving 18 barrels of crude oil or 4.7 tons of coal,” wrote the authors, who calculated that shutting down workstations during off-periods at their facility would equate to taking 11.6 cars off the road, saving 14.9 barrels of oil or 39 tons of coal.
“Radiologists have the unique opportunity, as technological leaders, to direct energy efficiency measures as a means of cost savings and the reduction of airborne by-products from energy production to improve patients' lives,” added the authors, who noted that particulate matter produced by burning coal and fossil fuels is linked to respiratory system damage and cancer.
The researchers also suggested some other energy saving techniques in addition to turning off workstations at the end of the workday. Upgrading to higher efficiency computers as well as switching from cathode ray tube monitors to LCD monitors could yield savings. A switch to solid state hard drives would lower energy consumption, though the authors acknowledged they are currently much more expensive than traditional hard drives.