Berkeley Lab Researchers Developing Energy-Efficient Digital Network Technology

By Consulting Specifying Engineer Staff April 12, 2007

Scientists at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) are developing technologies to make electronic networks—whether they are used for the Internet, consumer electronics, or both—more energy-efficient. They also are developing specifications and information programs to speed the adoption of energy-efficient technologies in the marketplace.

“The purpose of this research is to reduce electricity use of electronics used in digital networks,” said John Busch, a scientist in the Environmental Energy Technologies Division and the project’s principal investigator.

Studies suggest that total energy consumption of electronics in the United States is more than 70 trillion watt-hours per year (TWh/yr) of electricity, costing billions of dollars, and equivalent to at least 50 million metric tons of carbon dioxide emissions per year. In fact, recent independent studies suggest this figure could be as high as 250 TWh/yr. Most of these electronics already are networked, and the number of devices continues to grow.

Some estimates suggest that one-third of this energy could be saved with full use of power management on desktop computers, currently the most common of devices on the Internet.

However, many PCs don’t use their power management features, often because they don’t stay connected to the Internet when they go into power-saving modes. Also, the number of power-consuming electronic devices used to connect to the Internet in homes is increasing.

Because of funding from the California Energy Commission’s Public Interest Research Program (PIER) and the U.S. Environmental Protection Agency, Berkeley Lab scientists have begun studying a variety of ways to reduce the energy use of computer networks. The commission’s PIER funding is $1.3 million.

The project has three components related to networks, and three addressing consumer electronics. One project component will look for a way to allow a PC to maintain a continuous network presence even when it’s in sleep mode. This project will examine proxying as an energy-saving strategy: transferring the sleeping PC’s network connectivity to a built-in network interface or an external device such as the local network switch. This proxy responds to routine network traffic as the PC sleeps, and it awakens the PC only when necessary.

Another project component will develop energy-efficient specifications for network equipment, which could be adopted by organizations like Energy Star to help manufacturers and consumers move to more efficient technology.

Three tasks are aimed at making consumer electronics more efficient. One aims to get more use out of energy-saving technologies already present in the standard but not widely used in products. Another will focus on making it easier for consumers to put products in the “sleep” and “off” states when they use handheld remote controls and other control devices, and to automate transition to these states when the devices are not in use.

One project is studying set-top boxes (STBs), which control the transmission of digital video and audio. “Energy use by STBs is increasing rapidly,” said Environmental Energy Technologies researcher Alan Meier. “In this project, we are identifying ways to increase the energy efficiency of these devices.”

Finally, a market-oriented component will provide builders with lists identifying the most energy-efficient models of hard-wired and builder-installed equipment to specify in new homes. “Previous Berkeley Lab research shows that new types of builder-installed products, such as structured wiring systems for smoke alarms, doorbells, and garage door openers and other remotely operated devices are significantly increasing energy consumption by these products,” said Rich Brown, division researcher. “This will help builders install the most energy-efficient equipment.”

For more in formation on the Energy-Efficient Digital Networks project, see
https://efficientnetworks.lbl.gov/enet.html