The Future of Plug-In Hybrids

Right now, PHEVs are strictly retrofits: No large manufacturer mass-produces them. The first demonstration was in 2002 courtesy of advocacy group CalCars. Since then, a professional and cottage industry of Prius retrofit companies and shops have sprung up. Among these companies are Canada’s Hymotion, which was acquired by Boston-based lithium-ion battery company A123 Systems, which is operating with $250 million of corporate and venture capital funding.The company is in the game and was at the conference. Also at the conference was San Francisco-based Luscious Garage – led by owner, self-described “recovering academic” and mechanic Carolyn Coquillette. 

Retrofits cost between $5 to $10 for labor and an additional $3,000 to $20,000 for battery costs, depending on the desired performance and battery. The cheapest batteries are the tried and true but heavy and bulky lead acid.

The simplest PHEV architecture is the series hybrid. In this model, the car’s gasoline engine does not directly drive the wheels. It exists only to charge the battery, which powers the car. No carmakers mass-manufacture these yet. General Motors hopes to be the first with its Chevy Volt, which is expected to reach showrooms by late 2010. The Volt is designed to go 40 miles on a single battery charge before the engine needs to recharge the battery, which gives it the designation of a PHEV40. Research universities are also tinkering with split-power hybrids where the gas and electric motors power different wheels on a car. The Union of Concerned Scientiests (UCS) has a superb Website and click-to-move graphic that explains these differences.

Toyota is also working on a Prius plug-in but hasn’t yet announced a commercial release date, although a fleet of 10 demonstrator Prii are being released on a limited basis to select members of the public by and with the results being recorded by the University of California Davis’ Plug-In Hybrid Electric Vehicle Research Center. The Center is funded with a $3 million grant from California Energy Commission’s Public Interest Energy Research Program. These demo Priis are designed to have a PHEV20 capability, their batteries are rechargeable with a 110-volt standard house plug, and in combined electric and gasoline mode they have a fuel economy of 100 MPG.

U.C. Davis has had a long association with Toyota, particularly in regarding testing and demonstrating Toyota’s hydrogen vehicles. The university has emerged as one of the more prominent universities with regard to energy research in the U.S.

Additionally, U.C. Davis is well known as the long-time home of Professor Andy Frank – widely acknowledged as the Godfather of PHEVs. Over the years he and his team of students have retrofitted nine concept or conventional vehicles as PHEVs, with the largest being a Chevy Suburban. (You can see a list of them here. Please note that some of the site’s links are broken and might take some googling to get more information and specification sheets, such as those for a Chevy Equinox PHEV called Trinity. More information is available here.) Frank is the Chief Technical Officer of Efficient Drive Trains Solutions Inc., which was founded around intellectual property all patented by and owned by Frank and/or U.C. Davis. 

Another luminary in PHEVs is Illinois Institute of Technology Professor Ali Emadi. Both Emadi and Frank were publicly recognized as PHEV oracles by Silicon Valley luminary Andy Grove, the conference’s Tuesday lunch-time keynote speaker. Grove is a PHEV fan, and the former CEO and Chairman of Intel. Grove described a vision of creating a franchised business via already in-place automotive repair shops to retrofit PHEVs as the owners of many on-road pick-ups; sport utility vehicles and vans are feeling some intense pain at the pump presently. Emadi is also the Founder and President of Hybrid Electric Vehicle Technologies Inc., which previewed a Ford F-150 pickup PHEV retrofit at the conference.

Besides needing more refined architectures, more importanly PHEVs need smaller, lighter, more powerful, more robust and cheaper batteries. On a per pound basis, lithium-ion batteries provide greater energy density than the lead acid batteries or the nickel metal hydride batteries in today’s most successful hybrid vehicles, but they can have “heat management issues” which can result in a fiery melt down. Toyota, according to some, rejected the use of lithium ion batteries for its new generation Prius and chose to stay with the standard nickel metal hydrides until this safety related issue is thoroughly solved. (You can see an evolving list of Prius retrofit and kit options here.) 

Battery companies, however, are tackling this issue by changing the structure and chemistry of the components that make up lithium-ion batteries. A123 Systems, for instance, has a lithium-phosphate battery, which they say is far less prone to runaway thermal reactions than classic lithium cobalt batteries that are in today’s laptop and notebook computers. Others such as Altair are working on lithium titanate batteries. Still other companies, notably Tesla Motors, are sticking with lithium cobalt batteries but building greater safety mechanisms around them.

Cost, though, will likely remain an obstacle. While the premium on assembly line plug-ins will be lower than the $8 to $30 price for a retrofit, they will come with a $5,000 or higher price than hybrids, which sell for a premium of around $3,000 on conventional vehicles. With $5 a gallon gas, a consumer could drive a car that gets a lowly 20 miles per gallon and enough gas to drive for nearly three years for the same incremental cost for as a plug-in once they are mass-produced, or for significantly more at today’s cost of a major retrofit.

In fact, GM recently upped the prospective price of the Volt from $30,000 to $40,000, with this price differential being ascribed to incremental battery costs. As GM’s Larry Nitz, a conference speaker on the subject of PHEV power trains said: “Hybrids are way more expensive than conventional vehicles, and plug-ins are even more expensive than that."