Reducing CO2 Emissions Through Better Computer Design

Environmental considerations and the opportunity to reduce company expenses are fuelling the need for manufacturers of computer equipment to achieve higher efficiencies with their products over their expected lifetime. However, these efficiencies must be achieved with minimum disruption or changes to the habits of the end user (or impact on the employer's company policies). One approach that can contribute to addressing this challenge is to use Power State Indication (PSI) mode to lower mother board power usage at light loads and when the computer idles.

New studies show impact

From studies carried out on standard computer operation practices within the work environment we know that 60 percent of all computers are not switched off at night for various reasons, such as company policy, IT upgrades and time considerations. Of that 60 percent, we also know that half of these computers do not have any sleep modes enabled.

A survey carried out by 1E concluded that among employed adults who regularly use a PC at work:

Recorded user power down habits

Programs such as Energy Star set down regulations on energy consumption in off and sleep modes, with strict guidelines on the total energy consumption (ETEC) that must be adhered to in order to meet the Energy Star certification.

Where all Px are power values in watts, all Tx are time values in % of year, and the ETEC is in units of kWh. This represents annual energy consumption based on mode weightings in the table seen in this article.

However, it has been the practice for some companies not to activate hibernation modes or for individual users to disengage this function on their PC. This results in higher energy costs than would otherwise be achievable. Indeed, according to the Climate Savers Computing Initiative, some 30 percent of all computers sold to the work place potentially never enter a power save or off state.

Energy Star Guidelines for Desktop PC