Developments on the Plug-In Hybrid Electric Vehicle Front

November 30, 2006 by Jeff Shepard

There were several announcements this week related to the continued development of Plug-in Hybrid Electric Vehicle (PHEV) technology and eventual commercial production. The plug-in hybrid systems differ from non-plug-in hybrid systems by offering extended electric-only propulsion, additional battery capacity and the ability to be recharged from an external electrical outlet.

The Electric Power Research Institute (EPRI) and Argonne National Laboratory, two of the nation's premier research organizations, announced a three-year collaborative agreement to conduct detailed analysis of PHEVs aimed at assessing the commercial feasibility of this technology for the U.S. Department of Energy.

The EPRI and Argonne analysis will evaluate PHEVs, hybrids and conventional vehicles, assessing them from environmental, cost, design, and marketing perspectives. The engineering and technical studies will be conducted at the two organization's respective research facilities in Palo Alto, California, and Argonne, Illinois, and will involve the participation of some of the world's leading transportation experts.

The objective of the multi-year research project is to provide a balanced and authoritative study of both the advantages of and the challenges to the design and commercial production of PHEVs. An assessment of potential social benefits of PHEVs, including reductions in imported petroleum-based fuels, enhancement of American energy security and air quality improvement will be key components of the study.

The announcement of a major government-funded project was accompanied by news from the corporate world as well, as General Motors and Valence also revealed that they are undertaking major PHEV projects.

General Motors (GM), which had been criticized for releasing "gas guzzling" utility vehicles and for scrapping its EVA electric car program (the subject of the widely publicized documentary "Who Killed the Electric Car?"), announced that it intends to produce a Saturn Vue Green line of PHEVs which the company claims has the potential to achieve double the fuel efficiency of other SUVs on the market. The new hybrid SUV will use a modified version of GM's 2-mode hybrid system and plug-in technology, a Lithium Ion battery pack when ready, highly efficient electronics and powerful electric motors to achieve significant increases in fuel economy.

The vehicle is expected to offer electric-only propulsion for more than 10 miles. At higher speeds or when conditions demand it, such as brisk acceleration, a combination of engine and electric power or engine power only will propel the vehicle. In addition to plug-in capabilities and the modified 2-mode hybrid system, the Saturn Vue Green Line hybrid SUV's powertrain will feature Lithium Ion battery technology, two interior permanent magnet motors and GM's 3.6L V-6 gasoline engine with direct injection. The 2-mode hybrid system will be altered for use with plug-in technology, maintaining two driving modes - one for city driving, the other for highway driving - and four fixed mechanical gears to maximize efficiency while maintaining performance. In addition, special controls will be utilized to enable higher speeds during electric-only propulsion and maintain electric-only propulsion for longer periods of time. The first front-wheel-drive application of the 2-mode hybrid system will debut - without plug-in technology - in the Vue Green Line in 2008.

Valence Technology announced that it has partnered with plug-in hybrid conversion company EnergyCS to deliver a fuel-efficient concept car for evaluation by the Sacramento Municipal Utility District (SMUD). The California-based electric utility company is testing the Valence U-Charge® powered plug-in to determine its fuel economy and fleet adaptability.

SMUD recently completed its first 1000 miles of testing and will continue to measure the vehicle's performance over the next 2-3 years. Data from the first 1000 miles and additional testing this summer will be presented along with other early adopter fleet data this fall. SMUD's pre-commercial plug-in hybrid demonstrator is based on a 2005 Toyota Prius that has been outfitted with Valence lithium-ion rechargeable batteries and custom electronics designed by EnergyCS to achieve increased efficiency and expanded operation in all electric or zero emission operating modes.

The U-Charge Power System inside the EnergyCS PHEV is based on Valence's proprietary Saphion® technology. Using a cathode material that replaces metal-oxides with phosphates, this technology creates batteries that are claimed to be safer, more chemically stable and environmentally friendly. These batteries are also claimed to provide more energy with less weight and last longer than nickel metal-hydride (NiMH) and lead-acid batteries. In addition, they are maintenance-free and come in 12V, standard lead-acid battery sizes.

In June 2006, SMUD began evaluating the PHEV technology within its fleet environment to gather data that could also be compared to the performance of a stock Toyota Prius. Though SMUD plans to officially release its results later this year, they have already found some encouraging numbers. The plug-in Prius uses 1/4 of a kilowatt-hour per mile, which is the equivalent of $1.48 per gallon, in all-electric mode. Compared to today's gasoline prices in California that are more than $2.45 per gallon the technology looks promising.