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Brainy buildings using "smart dust" can keep soaring energy costs in check, say UC Berkeley researchers
25 May 2001

By Media Relations


Kris Pister with microprocessors and sensors he uses to make his smart dust motes.
Photo by Peg Skorpinski

Berkeley - In the midst of California's energy crisis, how do you know if you're wasting power? Try asking your house. Or perhaps your office building.

That's the idea behind the smart energy technology being developed at the University of California, Berkeley's Center for Information Technology Research in the Interest of Society, known as CITRIS.

Using the emerging technology to create power-aware buildings could provide potential savings to the state of as much as $7 to $8 billion a year in energy costs, according to UC Berkeley engineers, energy and environmental experts. They also believe the technology could keep consumers' utility bills in check and reduce the need to build new power plants.

Earlier today, (Friday, May 25) at UC Berkeley's Cory Hall, engineers demonstrated how outfitting a building with a network of small, wireless sensors called "smart dust motes" can be teamed with sophisticated software to substantially conserve energy use.

"Our goal with CITRIS is to develop technology that can readily be put to use to solve large-scale, quality-of-life problems facing society. To address the energy shortages, our researchers have developed a prototype energy-management technology that can eventually be deployed for less than a dollar per sensor," said A. Richard Newton, dean of the College of Engineering.

The promise of the technology, said Newton, is that, in addition to the low cost of the sensors, using wireless technology makes it easy to install them in existing buildings. Equally important, he said, "is that this new technology uses a highly reliable, secure and sophisticated software architecture that will allow us to truly build an intelligent control system - real 'smart houses' and 'smart buildings.'"

"One of the main goals of CITRIS is learning how to manage communal resources, whether the resource is energy or time or roads," said UC Berkeley electrical engineering professor Jan Rabaey, co-author of the CITRIS "Smart Energy Distribution and Consumption" white paper that details how information technology developed at UC Berkeley can help address California's energy future.

To demonstrate a CITRIS approach to the energy crisis, Rabaey and fellow scientists and graduate students installed more than 50 solar and battery-powered smart dust motes throughout Cory Hall, which houses the Department of Electrical Engineering & Computer Sciences.

Cory Hall was built in 1948, long before energy conservation was an issue, and is one of the heaviest electrical users on the campus. The sensors, outfitted with wireless radio transceivers and their own "TinyOS," a tiny operating system developed specifically for them, recently were installed in office corners, conference rooms and along hallways. There, they are keeping a constant vigil on light and temperature conditions. In place for less than a week, the sensors already are supplying information that is helping the facility manager control the building's electricity use.

"This SensorWeb will provide huge reams of data about what's actually happening at any moment," explained electrical engineering professor Kris Pister, developer of the smart dust sensors and co-author of the CITRIS white paper on energy. "People really have no idea where electric power is actually being burned in their homes or offices."

For instance, imagine clicking on the energy Web page for your home and seeing how much each of your appliances - a hallway nightlight or the second refrigerator in the garage - is costing you to operate at that moment.

Watching a virtual cash register go "ka-ching" every minute your air conditioner blows may make it easier to settle for a slightly warmer home or to get up to turn a light off.

UC Berkeley researchers believe they are very close to putting smart energy technology to work. With the wireless sensors already developed, now it's time, they say, to make the matchbox-sized sensors even smaller and reduce the cost of manufacturing from the current $100 prototype cost to less than $1 apiece. Finally, the researchers need to work with industry to bring the technology to the marketplace.

Industry partnerships are a key component of Gov. Gray Davis' new California Institutes for Science and Innovation. CITRIS is one of these new University of California institutes and is being undertaken in partnership with three other UC campuses and California industry. It is hoped that the legislation to fund CITRIS will be passed into law in Sacramento next month. In addition to energy work, CITRIS will tackle problems associated with health care, education and transportation, among other large-scale problems perplexing society.

CITRIS scientists say that once the buildings have a bit of brains, the next technological step is to evolve today's passive sensors into more active sensors. The next generation smart dust motes could then intelligently cut power automatically to certain devices during times of peak power demand.

"Everything should have its own built-in intelligence," Pister said. "Wouldn't people rather spend several hours a day with their power intelligently reduced by 20 percent instead of having a one-in-five chance that they'll be cut off entirely as part of a rolling black out?" Pister said. "Then critical equipment could continue to operate."

According to other CITRIS research, real-time pricing of electricity - combined with the smart sensor technology - may be one key to limiting peak demand. By receiving real-time pricing information, a smart refrigerator, Rabaey explained, could know to fire its compressor only during off-peak periods when power prices are low.

The impact of such smart appliances is greater than one might think. According to the CITRIS white paper, as little as a 1 percent load reduction due to demand response can lead to a 10 percent reduction in wholesale prices, while a 5 percent load response can cut the wholesale price in half.

"Economists understand market forces, but you need an engineering approach to control those forces," said Shmuel Oren, professor in the Department of Industrial Engineering & Operations Research and UC Berkeley director of the Engineering Power System Research Center.

Oren, along with computer science professor Pravin Varaiya and others, hope to upgrade California's energy marketplace with more efficient commodity trading models.

By incorporating CITRIS smart energy technology to reduce peak-hour loads with real-time pricing for electricity, the researchers believe price pressure on wholesale market can be eased. That, in turn, will enable energy prices to drop across the board.