Tai Stillwater

Helping People Save Energy through Instant Feedback

By Jamie Knapp • J Knapp Communications

Zooming along at 80 mph? If you had one of those new cars that provide instantaneous feedback about your energy consumption, you’d know that you’re using 22 percent more fuel than at 50 mph. Maybe then you’d lighten up on the gas pedal.

Driven by government energy efficiency and emissions requirements, major automakers are now investing millions of dollars in computerized energy feedback systems. Likewise, electricity companies are experimenting with a host of information devices and strategies that encourage customers to dial down their energy use at home and at work. As they make these investments, the companies want to know, for sure, that the systems they’re designing will appeal to consumers and will result in energy savings.

So they’re turning to experts like ITS-Davis postdoctoral researcher Tai Stillwater for insight. Stillwater studies how consumers respond to information they receive about their energy use. Today, he’s at the center of a growing field that merges behavior theory with technology innovation.

“I think energy feedback will have a real impact on energy use in the U.S. by changing consumer behavior. Plus, it could have important implications for policy-making,” he says.

Stillwater currently splits his time between the institute’s Plug-in Hybrid & Electric Vehicle (PH&EV) Research Center and the university’s Western Cooling Efficiency Center.

“I’ve found my passion,” he says. “My vision is that everyone should have easy access to great energy feedback if they want it.”

Stillwater’s desire to reduce the energy we use in everyday life stems from two observations.

The first is that it’s not hard to do. Stillwater discovered what’s possible as an undergrad at UC Berkeley working on their Human Powered Vehicle Team, which broke multiple world speed records with a carbon-fiber bicycle that he helped design and manufacture. He acknowledges the technology is not for everyone, but it showed him “we’re using many more times the energy we need to achieve travel.”

His second observation is that a lot of people in the world are desperate for the energy that Americans consume every day and take for granted.

“We in the U.S. have access to as much energy as we want. The rest of the world doesn’t,” says Stillwater. “As world citizens, maybe it’s our duty to reduce our energy consumption and to leave a little for other people in world.”

Stillwater worked with PH&EV Research Center researchers Ken Kurani and Tom Turrentine on the center’s landmark 2010 study, “Plug-In Hybrid Electric Vehicle (PHEV) Demonstration and Consumer Education, Outreach, and Market Research Program.” His contribution, which examined driver response to fuel-use feedback, found that the highly successful drivers who cut their fuel use by six percent were personally motivated to save money by saving fuel. Their own personal motivations, which Stillwater refers to as context, combined with immediate fuel-use feedback, prompted them to adjust their driving behavior accordingly.

Context enables individuals to understand when and how much of an effect they can have on energy use, according to Stillwater, and is a critical component of energy feedback research. Providing context as part of the driver feedback mechanism is more difficult than it appears, however, because each driver’s personal abilities and roadway situations are different.

Stillwater, Kurani and their colleagues are also examining ways to tap into to individuals’ proclivity for competition and cooperation.

“It’s very powerful to provide energy performance data to users in a broader context that includes information about how other people are performing,” says Stillwater.

So how do drivers get this feedback? Through vehicle-integrated computers or smartphones that combine their driving behavior with the vehicle’s operational and external data, and then display that data visually in real time so they can connect their driving performance to an outcome.

One study, funded by U.S. DOE and Oak Ridge National Lab (ORNL), is testing the effectiveness of three different design interfaces that present information to the driver in different ways. One interesting – and surprising – result is that drivers respond more to feedback with numerical, rather than purely graphical, information.

“This is a useful finding because it contradicts conventional wisdom – that green leaves or other graphic symbols motivate better behavior,” Stillwater says. “It indicates that drivers have a real need for basic data about their energy use to make better decisions.”

Energy feedback research has benefitted tremendously from recent advances in information technology, Stillwater says. Thanks to the boom in cloud computing, the cost of collecting and tabulating data from geographically dispersed individuals and sending useful information back to them has decreased tremendously.

There was a time not long ago, he notes, when policy makers rejected behavior change policy, instead supporting requirements on vehicle technologies. Now, he says, information technology advances inspire effective voluntary behavioral approaches.

When consumers receive accurate information about both their energy use and their individual potential for creating change, and it is relevant to their personal beliefs, they will become advocates for better technologies, information systems and efficient vehicles.

“People are more informed and willing to save energy than they were 20 years ago,” he notes. “If we keep moving in that direction, we will greatly reduce energy use. It’s up to researchers and entrepreneurs to provide consumers with products that make them feel good about saving energy.”

Photo: ITS-Davis postdoctoral researcher Tai Stillwater displays an energy feedback system in a Chevy Volt, October 2012 (Dorian Toy – UC Davis)

Further reading:

Stillwater, Tai and Kenneth S. Kurani (2011) Field Test of Energy Information Feedback: Driver Responses and Behavioral Theory. Transportation Research Record: Journal of the Transportation Research Board 2252, 7-15
http://www.its.ucdavis.edu/?page_id=10063&pub_id=1597

Stillwater, Tai and Kenneth S. Kurani (2012) Goal Setting, Framing, and Anchoring Responses to Ecodriving Feedback. Institute of Transportation Studies, University of California, Davis, Working Paper. UCD-ITS-WP-12-03
http://www.its.ucdavis.edu/?page_id=10063&pub_id=1660

Stillwater, Tai and Kenneth S. Kurani (2012) Preliminary Results from a Field Experiment of Three Fuel Economy Feedback Designs. Institute of Transportation Studies, University of California, Davis, Working Paper. UCD-ITS-WP-12-01
http://www.its.ucdavis.edu/?page_id=10063&pub_id=1658

Stillwater, Tai, Kenneth S. Kurani and Patricia L. Mokhtarian (2012) Cognitive Mechanisms of Behavior Change in the Case of In-Vehicle Fuel Economy Feedback. Institute of Transportation Studies, University of California, Davis, Working Paper. UCD-ITS-WP-12-02
http://www.its.ucdavis.edu/?page_id=10063&pub_id=1659

Stillwater, Tai (2011) Comprehending Consumption: The Behavioral Basis and Implementation of Driver Feedback for Reducing Vehicle Energy Use.  Institute of Transportation Studies, University of California, Davis, Research Report UCD-ITS-RR-11-13 [http://www.its.ucdavis.edu/?page_id=10063&pub_id=1518