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Toyota's VP Miller Tips Hat to Prius Converters
Jul 27, 2007 (From the CalCars-News archive)
This posting originally appeared at CalCars-News, our newsletter of breaking CalCars and plug-in hybrid news. View the original posting here.
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It's nice to be appreciated...especially by people whose cars we've green-tuned without permission in order to show how to make good cars better! Here, on the Toyota Open Road Blog, Irv Miller, Toyota Motor Sales Group Vice President - Corporate Communications, conveys the company's positive views about conversions. And after you read what he says, you can see that this moderated blog graciously accepted its first public comments from Jon Wellinghoff about vehicle-to-grid, and from us about the broader implications of conversions.

July 26, 2007
IRV'S SHEET: Toyota Plug-in Hybrid Testing Comes to the U.S.A.­2007/­07/­readers-of-this.html

Readers of this blog no doubt will be interested to note Toyota's announcement Tuesday that it will put Toyota plug-in hybrid electric vehicle (PHEV) prototypes into testing here in the U.S.

That's both good, and not at all surprising.

It's good because it further demonstrates the company's engineering depth and its eagerness to experiment with, and to continue developing, this important technology.

It's not surprising because the plug-in hybrid seems like such a natural avenue of research for Toyota, an extension of Toyota's now decade-long commitment to the concept of the gas-electric hybrid, more widely known as Hybrid Synergy Drive.

If you happen to live near California's East Bay area, or in Orange County, keep your eyes peeled. That's where these interesting new cars will be found beginning later this year, when researchers at the Advanced Power and Energy Program at the University of California, Irvine (UCI) and the Institute of Transportation Studies at the University of California, Berkeley (UCB) will begin their assessment of PHEV technology.

Unfortunately, these are the only places they'll be found. Toyota's plug-in hybrids will not be available to the public until a great deal of additional research has been done.

There are several elements of the upcoming research that will be done. One of them will involve the overall carbon footprint of the plug-in hybrid. This is of interest because of the potential impact on the nation's power grid of a PHEV fleet.

One of the primary selling points of the Prius, and other Toyotas with Hybrid Synergy drive, is that its battery package is kept charged by a combination of the vehicle's efficient gasoline engine and its regenerative braking system. This flexible system will operate in full electric mode, full gasoline mode or in a combination of both modes, taking full advantage of the benefits of the parallel hybrid concept, which unlike a series hybrid builds on the strengths of both types of power sources.

The fact that the vehicle's battery never has to be plugged in is a major selling point, one that the driving public appears to have embraced, as witnessed by sales of more than 604,000 Toyota hybrids in the U.S. since 2000, including a projected 175,000 in sales of Toyota hybrids this year.

The Toyota PHEV prototypes, which are based on the Prius, work somewhat differently. In addition to the expected gas engine, PHEV prototypes also will carry oversized packs of nickel-metal-hydride (NmH) batteries. These battery packs are intended to simulate the level of performance Toyota expects to achieve when it develops more advanced, compact and powerful battery systems another area currently being researched.

This prototype PHEV system is designed to operate much like the current Prius, switching from pure-electric mode, to gas-engine mode to a combined gas-electric mode.

But the PHEV system has an interesting difference: The PHEV's NmH battery pack is capable of storing significantly higher levels of electricity - electricity that is brought on board by plugging the vehicle into a standard wall outlet for periodic charging sessions. With significantly more electric power in reserve as a result of these charging sessions, the PHEV is capable of operating in pure electric mode for longer periods of time, and at higher speeds, than the current Prius. This will result in substantial gains in fuel economy, and a major reduction in total tailpipe emissions, over current conventional hybrid systems.

It must be noted, however, that in electric-only driving, PHEV range remains limited - something like seven miles. That's a reality check on the capability of the batteries that are currently available, and on the relative infancy of this technology. But as an aside, we should also point out that seven miles is also well within the range of the weekend chores done in many households. It means that even with this infant technology, many Americans could accomplish weekend shopping, soccer games, etc., without burning a drop of gasoline.

As good as the PHEV concept sounds, there is no free lunch. The electricity that provides the additional charge for the PHEV's batteries must be generated somewhere. If it's not generated by the PHEV's gas engine, then it's generated either by a hydroelectric plant or by a generating plant that burns coal, natural gas or some other fossil fuel.

We're immensely gratified that some enthusiasts, in a tacit endorsement of the hybrid concept, are, on a vehicle-by-vehicle basis, converting Toyota hybrids to plug-in technology. But doing one-by-one conversions is a different kettle of volts from making this technology viable for the sale of hundreds of thousands of cars, at an affordable price, with a reasonable reliability expectations and reasonable warranty, serviceable at any Toyota dealer anywhere.

That said, the interest in conversions continues to validate hybrid technology as a core technology that's here to stay. And it should come as no surprise that the further advancement of hybrid technology is a top priority for Toyota. We believe that it's the way forward.

So, apparently, do many Americans. Despite decreasing tax credits here in the U.S., demand for vehicles with Hybrid Synergy Drive continues to climb. In fact, a recent study by the National Renewable Energy Laboratory says hybrids have saved close to 215 million gallons of fuel in the United States since their introduction in 1999.

Additionally, Toyota estimates that over the past decade, hybrids worldwide have emitted approximately 3.5 million fewer tons of CO2 than gas-powered vehicles of the same class.

As research into this interesting and useful technology by Toyota and its partners continues, and is applied to production vehicles, those figures can only improve. And that can only be good. And, as noted earlier, it's not at all surprising.


What about vehicle-to-grid capability for the Toyota PHEV? Is Toyota planning on incorporating this "cashback" hybrid technology into the cars they produce for testing? Studies have demonstrated that PHEV with vehicle-to-grid capability can realize annual payments from electric grid operators of between $1,000 to $3,000. These cashback payments could completely offset the high cost of this technology. What is Toyota doing in this regard?

Jon Wellinghoff
Federal Energy Regulatory Commission

Thanks to Toyota for going ahead with the first Prius PHEV prototypes! This is a major step forward.

And it's very gratifying to (we did the first Prius conversion) to hear Group VP Miller say the company is "gratified" that we've helped make their cars look better -- we've heard much the same thing from representatives at auto shows and from our dealers. We agree that conversions "validate" hybrid technology and its logical end-point: displacing most gasoline with electricity from ever-cleaner sources. And of course, Toyota can do it better than any garage engineers or small aftermarket companies.

The future opportunity is two-fold: for Toyota to mass-produce PHEVs and to find some way to "electrify' some of the hundreds of thousands, soon to be millions, of hybrids already on the road. Toyota could sponsor this, for instance, through Toyota Racing Development. And as we report today in CalCars-News, one company, A123Systems/Hymotion, has invited the California Air Resources Board to award future ZEV credits to the maker of the original car for conversions. We hope this is an issue Toyota will explore.

-- Felix Kramer, Founder, The California Cars Initiative (

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