Is
There a Hybrid in Your Future?
(36-6)
With
the emergence of increasing government regulations on
the “Corporate Average Fuel Economy” (CAFÉ)
for new vehicles, many people are considering the purchase
of a car or truck that operates on a combination of
regular fuel and electricity. These are called Hybrid
vehicles.
There are two types of vehicles currently being offered
by the automotive industry: “series” hybrids
use either a gasoline or diesel engine to operate an
electric generator that provides the energy needed to
run one or more electric motors that drive the wheels;
“parallel” hybrids can use either the gasoline
engine or the electric motor to power the wheels directly,
or to work in combination with each other when extra
power is needed.
Idling in a situation like rush hour traffic in a major
city can burn a lot of fuel, creating pollution, and
overheating engines. To address this situation, the
Toyota Prius and several other hybrid vehicles turn
off the supply of fuel to the engine when you take your
foot off the accelerator, and the electric motor turns
into a generator to recharge the battery while the vehicle
slows down. The electric motor also acts as a dynamic
braking device to slow the vehicle instead of having
to use the regular brakes. The engine stays off while
you are sitting in traffic, and when you need to move
ahead, the electric motor uses stored energy from the
batteries to start the vehicle moving, then the high
voltage batteries use the power of the electric motor
to instantly start the gasoline or diesel engine to
continue accelerating to the proper speed.
The air conditioning, radio, windshield wipers, lights
and other accessories continue to operate from battery
power when the engine is shut down. If the computer
system determines that there is not enough stored energy
in the battery to restart the engine, then the gasoline
engine stays running while you are stopped, keeping
the alternator generating power to recharge the battery.
Larger Hybrids on the
Horizon
To achieve a practical degree of success in reducing
the fuel used by commercial vehicles, and the larger
cars and trucks that North Americans require, the hybrid
technology has to be applied to vehicles that can replace
gas powered mid-size pickups and sport utility vehicles.
For example, Toyota offers a hybrid version of the popular
Highlander SUV. This gas-electric model generates a
whopping 270 horsepower, yet still gets more than 960
kilometres to a tank of gas. That’s pretty serious
performance no matter how you slice it.
 Ford
has a gas-electric Escape SUV that uses a small gas
engine that works in conjunction with an electric motor.
The gas engine keeps the vehicle cruising along at driving
speed, and the electric motor kicks-in to provide extra
power for passing, accelerating from a stoplight or
pulling a small trailer up hills. The system provides
the kind of driving performance one would expect from
a traditional gas-powered SUV, while providing significantly
improved fuel economy and far lower hydrocarbon emissions.
Daimler-Chrysler is also into the clean power race in
a big way with its Jeep Grand Cherokee. Rather than
a gas-electric hybrid system, Jeep engineers opted for
a clean-burning diesel engine that provides ample power
and trailer-towing ability, while producing far lower
emissions than comparable gas power plants. I have driven
the Grand Cherokee with this clean-burning diesel engine
and it is exciting to drive.
There is a new wave of hybrid technology coming from
the automotive industry. For those who have been dreaming
of an Accord with V6 performance and the fuel economy
of a Civic, their patience will soon be rewarded, as
Honda recently launched the new V6 Accord Hybrid. The
new model uses Honda's Integrated Motor Assist (IMA)
hybrid system with Variable Cylinder Management (VCM)
technology to achieve fuel economy equivalent to a four-cylinder
Civic, while providing V6 performance. The V6 Accord
Hybrid is clearly intended to compete with Toyota's
mid-size Prius, and it is designed for projected fuel
economy equal to the compact Civic, while providing
a mid-size package and performance surpassing that of
its Accord V6 Sedan sibling, already powerful at 240-horsepower.
What if you really need a pickup? General Motors will
soon offer hybrid versions of the full-size Chevy Silverado,
Sierra, Yukon and Escalade trucks. These vehicles use
a gas-electric system and are capable of hauling much
larger trailers than any existing hybrid vehicles. In
fact, GM says the new Hybrid Silverado will have the
same towing capability as its current 1500 truck with
the 5300 V8 gas engine! One would have to expect that
heavy-duty 3/4-ton versions capable of handling big
fifth wheels and large truck campers won’t be
too far off in the future. Ditto for hybrid motorhomes,
especially since GM’s Allison division already
makes biodiesel-electric hybrid buses.
There are 800 million vehicles on the road today, and
in 15 years there will be 1.1 billion vehicles, so to
be sure that transportation grows in a sustainable way,
we need to address the energy diversity and get some
flexibility into the sector.
At the January North American International Automotive
show in Detroit, Bob Lutz of General Motors introduced
the E-Volt car that uses a small gasoline engine to
charge the on-board batteries that power electric motors
to drive the wheels. General Motors is talking about
plug-in hybrids and the need for the development of
new batteries. This year they introduced several hybrids;
the Saturn Vue, Aura, and the Chevy Malibu. Since plug-in
hybrids use more electricity from the grid, the GM engineers
want to make sure that they are working on the right
type of batteries for the future.
The current focus of hybrid research and development
is concentrating on a Lithium-Ion traction battery specifically
designed to provide power and energy to propel vehicles.
The concept is that “two-mode” power will
provide “eV” operation at very low speeds.
To avoid draining power from the grid, the batteries
will recharge only when driving and are designed for
very limited electric drive operation. A “two-mode”
plug-in hybrid would have to provide more than ten miles
of all-electric driving on a single charge, and the
batteries would charge while driving and when plugged
in. To be viable, this category of vehicle will have
to provide full electric propulsion up to city traffic
speeds and a range of forty miles in city driving. It
would be charged by an on-board generator through regenerative
braking and also by plugging into the wall. For the
general public to accept these vehicles as a viable
replacement for their gasoline or diesel cars and trucks,
all of the proposed solutions will have to be designed
to last ten years or 150,000 miles.
Battery technology is
the key
For the electric vehicle fleet to be successful, new
developments in battery technology will have to become
available at realistic prices. The key differences between
current batteries and the future designs lie in the
balance between power and energy requirements. Compare
the charge power required to operate the electric vehicles
available today… with gas and electric motors,
the “two-mode” hybrid can be used as the
baseline for this comparison; energy requirements increase
marginally for two-mode plug-in vehicles, but for full
electric drive operations the power requirements for
a vehicle like the Chevy Volt increases to more than
120 kilowatts (roughly three times that of a two-mode
hybrid vehicle). In terms of energy, the difference
is more dramatic. The two-mode hybrid uses significantly
less energy than vehicles that depend on electric drive
only.
 Obviously,
different battery solutions are needed for two-mode
compared to plug-in hybrid electric vehicles. How the
batteries are used also varies greatly as well - a typical
HEV (Hybrid Electric Vehicle) battery will use the stored
electric energy down to a nominal state of charge of
5 or 10%, while a plug-in electric vehicle will deplete
the battery to the point where it can no longer provide
electric drive.
The Lithium-Ion batteries that power the cars and trucks
of the future will be a significant part of the vehicle
cost, and we must develop solutions that will last for
the life of the vehicle, and achieve the shelf life
and cycling life requirements of the marketplace. The
challenge is to develop the new batteries along with
the new vehicles. This will be the key challenge of
hybrid technology - automotive lithium ion battery manufacturing
must build on the millions of high power batteries produced
for consumer devices today, to develop the power source
for successful plug-in hybrid and electric vehicles.
Most of the current battery manufacturing capability
is centered in Asia. To achieve the goals of the automotive
industry over the next few years we will see the emergence
of large format lithium-ion research specifically delegated
to automotive solutions, and manufacturing investment
will be needed within a year or two to meet demand projected
by the end of this decade. Development of a domestic
automotive battery manufacturing capability will be
critical to future energy security. More active government
support for scaling-up this production may be necessary
because we know that mass production of high quality
affordable lithium-ion batteries will be required to
enable the widespread electrification of the automobile.
At this point in the development of hybrid and electric
vehicles, all of the attention is focused on creating
viable cars, busses and trucks – but what is going
to happen when the batteries have reached the end of
their usefulness - what will we do to prevent environmental
problems ten years down the road at end of the life
cycle for the battery?
The anticipated environmental impact of the hybrid and
electric vehicle battery is actually more positive than
our existing situation – today, we recycle many
lead-acid batteries, but the lithium-ion chemistry that
will be used for the next wave of vehicles actually
has less damaging environmental impact when properly
recycled at disposal time.
So the answer to the question “is there a hybrid
in your future” is definitely “yes”,
in one form or another, and this is great news for RV’ers.
As the new technologies develop to power larger vehicles,
we will be able to enjoy better fuel economy and reliability
than we’ve ever seen, and we will reduce our personal
“carbon footprint”, resulting in far less
damaging impact on the natural world we all enjoy so
much. Any way you look at it, the development of hybrid
and electric vehicles will be a “win-win”
situation for everyone! (Page
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