BOULDER, CO - The University of Colorado at Boulder's Renewable and Sustainable Energy Institute (RASEI) is partnering with Toyota to study the impact of plug-in hybrid electric vehicles (PHVs) in a "smart grid" environment. 

RASEI is a joint venture with the U.S. Department of Energy's National Renewable Energy Laboratory. 

Toyota Motor Sales will supply 18 Prius PHVs for the two-year program. The cars, which are slated to arrive in mid-September, will be circulated in three-month stints among 108 randomly selected Boulder households that volunteered to be part of "smart grid" pilot tests. 

"This is a great example of CU working together with industry to address big-picture energy questions," said Michael Knotek, director of RASEI. "RASEI is here to make a real-world impact. With these partnerships and our 'smart grid' research expertise, we'll be able to get some new insights into the intersection of transportation and the electric grid." 

RASEI and Toyota Motor Sales, with help from Xcel Energy, will gather data on vehicle performance and electricity usage. They will also study how households interact with vehicle feedback through "smart grid" technology. The Boulder location also presents the opportunity for researchers to monitor the performance of Toyota's first-generation lithium-ion battery at high altitudes and in cold weather.

The 18 vehicles in the field study are part of a 150-vehicle demonstration program that Toyota Motor Sales is conducting throughout the United States. 

The Prius PHV can be charged in approximately three hours from a standard 110-volt electrical outlet, or in one-and-a-half hours with a 220-volt electrical outlet, and can cruise in electric-only mode for approximately 13 miles. For longer distances, the PHV reverts to its hybrid mode and operates like a regular Prius. 

A community blog on the field study will be hosted at For more information on the PHVs and Toyota Motor Sales' demonstration program, you can visit