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Experiences of 2 PHEV Early Drivers: Testimony to Air Resources Board ZEVTechnology Symposium
Sep 29, 2006 (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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We spent two very rewarding days at the California Air Resources Board's Zero Emission Vehicle Technology Review in Sacramento September 26-27. A few days ago, I described the background for this event at­calcars-news/­528.html. I delivered a shorter version of this text as accompanying commentary for our eight-slide-presentation, which you can see at    /presentations/presentations.htm, or at­calcars-arb-zev-kramer.pdf

We had been hoping that all the illuminating presentations would be available by now, but that hasn't happened. When they are available, we will post additional comments at CalCars-News.

We're also posting a copy of this at our blog,­blogs/­power/­early-drivers, where you can comment.

The Experiences of Two PHEV Early Drivers. By Felix Kramer, Founder, CalCars

I tip my hat to Toyota, EnergyCS, SMUD, Andy Frank, and the plug-in advocates who never give up.

In Sept 2004, I came to the ARB hearing on the implementation of the Pavley Bill. I my testimony­CalCarsARBTestimonySept04.pdf, I said "the elephant in the room" is PHEVs, which could start saving CO2 emissions faster than any other vehicle type. Several commissioners looked at each other, talked, and agreed it was necessary to re-visit PHEVs. I'm glad that's happening now.

Slide 2 INTRODUCTION My testimony reflects my experience as the world's first non-engineer consumer owner of a PHEV and that of my colleague Ron Gremban, an engineer and CalCars' Tech Lead, Ron is the owner/driver of the world's first PHEV Prius.

In the fall of 2004, Ron Gremban led a team that for the first time converted a hybrid production car (his 2004 Prius) into a PHEV. He has since driven his lead-acid PHEV 17,000 miles, charging mostly at his solar-panel-outfitted home. Then on April 7, 2006, I took delivery from EnergyCS of a lithium-ion conversion of my 2004 Prius. I have since driven 8,000 miles. Both cars are parked outside.

Many of the issues I address may be generalized to provide insight into the impact of PHEVs as they begin to penetrate the population of car drivers. I'll start with performance notes, followed by anecdotal reports and issues.

Slide 3 PERFORMANCE How things have changed! I used to dread a day filled with short trips. Even on the low-emissions Prius, each time I'd have another engine warm-up and much-reduced MPG. Now I love those local errands -- they're mostly all-electric. In my first two days, I drove 130.71 miles on 1.102 gallons of gasoline. That's 118 MPG. These numbers included an airport run with about 40 miles of 65 MPH highway driving.

Early on, I made a round-trip from the Peninsula to downtown San Francisco. I went beyond the mixed-speed range of the PHEV Prius: 64 miles, including about 55 at highways speeds (North on flat Rte. 101, back on hilly I-280). Bottom line: 81.4 MPG. That trip included 98 Watt-hours/mile or 6.2 kWhr out of the battery.

The slide shows a representative driving day with the "boosted" full or partial electric range: 50.8 miles of mixed-speed driving, at an average of 124.1 MPG plus 123 Wh/mile. The numbers speak for themselves.

We always try to say "100+ MPG (plus the cost of gasoline)." What does that work out to added up? The answer is 76-83 MPG equivalent, depending on assumptions (Sacramento Municipal Utility District or Pacific Gas & Electric power rates, and $2.75 or $3/gallon for the cost of gasoline).

These numbers demonstrate that 100+ MPG is possible with an after-market conversion that suffers from severe limitations of any conversion, including forced gasoline use above 34 MPH. An optimized, from-the-ground-up PHEV from Toyota and other OEMs could do much better!

As PHEV owners, plugging in is "optional," since we know we can reach our destinations with gasoline. Our reasons to plug in have evolved:

1. Saving money. 2. Reducing CO2 and other emissions. 3. Reducing use of imported fuels (doing our bit for energy independence) 4. The pleasure of driving silently on local streets at low-speeds, which accounts for more than half of our everyday driving. Ron's favorite) 5. The desire to avoid the generally negative experience of going to a gas station. 6. The intangible "gadget/techie/boasting" factor of being able to maintain high cumulative MPGs on a real-time display, and to achieve extended intervals between fueling by using more electricity.

While the final point may appear to be frivolous, it's a real -- and generally highly positive -- behavioral factor. It's the same dynamic at work among many Prius drivers who report that their ever-present "driving companion" (a feedback screen showing current and cumulative MPG) has affected them. It's why you hear many Prius drivers say they've changed to become safer, slower, cruise-control drivers. It's why you see many hybrid owners driving at or below the posted maximum speed on highways -- they've adjusted their driving behavior to the message that each additional mile over 55 MPH causes an aerodynamic hit of about 1 MPG. (In fact, if every new car came with a real-time MPG indicator, that could probably accomplish a 10-15% reduction in total vehicle fuel use faster than anything except getting people to keep their tires inflated!)

Slide 5 HOW DO I MAKE MY PERSONAL CALCULUS ABOUT WHETHER TO PLUG IN? Convenience is barely a factor. For home charging, it takes approximately 9 seconds to plug in when leaving the car, less than 9 seconds to unplug on the way out. When I'm traveling, I'm generally willing to explore the availability a 120-volt outlet in a hotel parking lot -- and I carry a 100 foot extension cord. And of course, the "dongle" -- when we brought my car to Washington, I showed that and said, "I've brought my infrastructure with me," which got a big laugh.

Price signals are the main factor (with my PG&E E-7 whole-house time-of-use meter).

Compared to this 7.6 cents, when the alternative is a 50 mile/gallon battery-sustaining Prius, gasoline wins on cost against on-peak charging until it reaches $3.80/gallon. Yet even at current $2.75-$3.25/gallon, I occasionally charge on-peak anyway. Why? Remember Slide 4? For reasons 2-6.

To the extent this "opportunistic charging" becomes a problem as more drivers plug in, it can be addressed with additional price signals, such as that included in the PG&E "Smart Meter" plan the CPUC recently approved, which includes both an additional off-peak discount and a "Critical Peak Pricing Plan" with a 60 cent/kWh surcharge on hot summer days.

The combination of solar electricity and PHEVs is a huge carbon-killer. In mid-September, I got a SunPower home rooftop photovoltaic installation. Initially, mine will be like the typical on-grid system: returning power to the grid in the day, recharging the car mostly during off-peak, night-time hours.

But in the power-outage and earthquake-prone SF Bay Area, people are highly interested when I explain that my system will later be uniquely configured for what I call "Vehicle-To-Home" (which provides a preview of to bi-directional Vehicle-to-Grid future). In extended power outages I will be able to manually disconnect/island the PV system from the grid and re-route the system's output. When the sun is shining, PV will power a small part of the house (one line, with refrigerator and lights) and charge the car. When PV power is unavailable, the car's batteries will power that line.

During an extended power outage and cloudy days, once the battery is depleted, the engine of the car (parked outside) can act as an emergency power generator with far lower emissions than the external generators available for these purposes. (Such emergency generators must be run every few weeks even when not needed, so they are maintenance headaches, and their fuel supplies are potential safety hazards.)

this doesn't belong strictly in a technical session. Suffice it to say that there's a growing interest and awareness, and many indications of specific support for PHEV commercialization. You can keep track of all this, and the continuing media attention, by joining the 4,000 subscribers to CalCars-News. At, you can also see:­carmakers.html -- the evolving views of auto-makers;­endorsements.html -- the high-level endorsements;­partners.html -- the growing coalition supporting PHEVs.

From 2001-2004, the main question I got was "What's a plug-in hybrid?" In 2005, that first question became, "Good idea, but how are you going to prove anyone wants them or will pay more?" In 2006, the question, at the growing number of public events promoting PHEVs, and every three weeks or so when I refuel, became, "How/when can I get one?" And going forward, we're expecting to be involved in activities that will help catalyze far more rapid adoption of this technology, with evolution of the range extender fuel as well.

Thank you for your attention!

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