Mercedes-Benz is showing the way
ahead in environmentally
responsible electromobility by
presenting its near-series
Concept BlueZERO at the North
American International Auto Show
in Detroit. Based on a single
vehicle architecture, this
intelligent, modular concept
allows three models with
different drive configurations,
all of which are able to meet
customer requirements in terms
of sustainable mobility:
-
the BlueZERO E-CELL with
battery-electric drive and a
range of up to 120 miles
using electric drive alone
-
the BlueZERO F-CELL (fuel
cell) with a range of well
over 248 miles using
electric drive
-
the BlueZERO E-CELL PLUS
with electric drive and
additional internal
combustion engine as power
generator (range extender).
This version has an overall
range of up to 370 miles and
can cover a distance of up
to 60 miles using electric
drive alone.
The three BlueZERO variants are
based on the unique
sandwich-floor architecture
which Mercedes-Benz introduced
some 10 years ago, initially for
the A-Class and then for the
B-Class, one of the aims being
to integrate alternative drive
systems. Advantages of the
modified construction include
the positive effect of the major
drive components on the centre
of gravity, their space-saving
design and the fact that they
are extremely well protected
within the vehicle underbody.
The five-seater BlueZERO concept
cars also set standards in terms
of lightweight design, interior
layout and body form.
"The flexible BlueZERO
concept allows electromobility
for every requirement and
highlights the fact that
Mercedes-Benz is the world's
only car manufacturer to already
have in place all the key
technologies for electric cars
offering full everyday
practicality," says Dr Dieter
Zetsche, Chairman of the Board
of Management of Daimler AG and
Head of Mercedes-Benz Cars.
The BlueZERO
principle: flexible design,
compact exterior, generously
sized interior
All three BlueZERO variants
share the same key technical
components, while the design and
vehicle dimensions are
identical. Measuring just 4.22
metres in length, the BlueZERO
models combine compact exterior
dimensions with a generously
proportioned and variable
interior and luggage
compartment. Five fully-fledged
seats, a payload of around 450
kilograms and a luggage
compartment capacity of over 500
litres make for outstanding
everyday practicality. Thanks to
their sandwich construction with
a raised sitting position, the
cars also offer an exceptionally
high level of crash safety for
the passengers and the
technology, not to mention
excellent all-round visibility.
Compared to electric cars
based on conventional vehicle
platforms and originally only
designed for use in combination
with internal combustion
engines, Concept BlueZERO offers
the following conclusive
advantages:
-
Interior space is
retained in full.
As the energy
accumulators/generators are
integrated into the spacious
sandwich floor, no
compromises are necessary
when it comes to passenger
space, luggage capacity or
variability.
-
The powertrain technology
built into the sandwich
floor ensures a low centre
of gravity and,
consequently,
extremely reliable and agile
handling.
-
Crash safety
is of the extremely high
standard associated with
Mercedes thanks to the
sandwich concept and the
housing of major powertrain
components between the
axles.
As
a result, the BlueZERO models
are very different to
conventionally constructed
electric cars, which have the
heavy and voluminous storage
battery housed in the boot or in
the rear-seat area, for example.
Modular design
ensures flexibility and
efficiency
"Our modular system allows
different drive configurations
for every customer requirement,"
says Dr Thomas Weber, the member
of the Daimler AG Board of
Management responsible for
corporate research and
development at Mercedes-Benz
Cars. "The modified
sandwich-floor platform provides
the perfect basis for a wide
model range with electric drive
systems. We are also developing
a new, additional platform for
future compact models with power
units based on optimised
internal combustion engines. The
intelligent networking of both
architectures enables us to
develop our product portfolio
extremely flexibly and
efficiently. From 2009, we will
be producing the first Mercedes
fuel-cell cars on a small scale.
Small-scale production of
Mercedes-Benz cars with
battery-electric drive alone
will then commence in 2010. This
means we are extremely well
equipped for the future."
All three BlueZERO models
feature front-wheel drive, which
is typical for this class of
car. The Mercedes engineers have
put together a modular system
comprising several flexibly
combinable drive components.
These include state-of-the-art
liquid-cooled lithium-ion
batteries with a storage
capacity of up to 35 kWh and the
compact electric motor with a
maximum output of 100 kW
(continuous output 70 kW), which
develops a peak torque of 320
Nm. All three variants
accelerate from 0 to 62 mph in
less than 11 seconds. Their top
speed is electronically limited
to 93 mph in the interests of
optimal range and energy
efficiency.
Electric drive
systems with a range of 120, 248
and well over 370 miles
With a charging capacity of
15 kW, the powerful lithium-ion
batteries in the BlueZERO E-CELL
and the BlueZERO E-CELL PLUS can
store enough energy for a range
of 30 miles within 30 minutes.
In terms of purely electrical
drive, one or two hours of
charging time is needed for a
range of 120 and 240 miles
respectively. The charging times
are doubled if the charging
capacity is 7 kW, as would be
the case in a normal household.
Both of these BlueZERO vehicles
incorporate an electronic
control unit that supports
intelligent charging stations
and billing systems.
At the rear, the BlueZERO
E-CELL PLUS has the same
1.0-litre turbocharged petrol
engine as the smart fortwo as an
additional range extender. This
compact three-cylinder
powerplant has an output of 50
kW at a constant 3500 rpm. If
required, it can recharge the
17.5-kWh lithium-ion battery by
means of a similarly rated
alternator. A range of up to 370
miles is possible on a single
tank. The purely electrical,
locally emission-free range is
up to 120 miles. The BlueZERO
F-CELL with fuel-cell drive
achieves a range of well over
248 miles with zero emissions
(as per NEDC).
BlueZERO E-CELL:
agile, quiet and locally
emission-free
The BlueZERO E-CELL is
equipped with a lithium-ion
battery with a capacity of 35
kilowatt hours (kWh). The
liquid-cooled high-voltage cells
have an operating voltage of 240
to 426 V. With this battery the
BlueZERO E-CELL has an operating
range of up to 248 miles.
Recharging the empty battery
takes three to four hours. The
BlueZERO E-CELL accelerates from
zero to 62 mph in less than
eleven seconds and, in the
interests of optimal range and
energy efficiency, has an
electronically limited top speed
of 93 mph.
BlueZERO F-CELL:
emission-free driving on long
journeys with the fuel cell
The new-generation fuel cell
used in the BlueZERO F-CELL is
more compact and – with a
maximum output of 90 kW
(continuous output 80 kW) – also
more powerful than its
predecessor. It can be
cold-started at temperatures
down to minus 25 degrees Celsius
and also has the benefit of
short refuelling times.
On
the road, the BlueZERO F-CELL
ensures a high standard of
dynamic handling, yet this
family-friendly compact returns
a highly impressive 97.4 miles
per gallon of fuel (diesel
equivalent). According to the
NEDC, the BlueZERO F-CELL is
able to cover well over 248
miles on one tank of hydrogen.
In
the fuel cell version of the
BlueZERO, the electric motor,
high-voltage battery and
hydrogen tank are likewise
positioned beneath the passenger
cell to save space. The system
uses the most efficient energy
source for the current driving
situation. When parking or
manoeuvring at slow speed, for
example, the electric motor uses
only battery power. When
accelerating, energy is provided
by both the fuel cell and the
battery. When braking, the
electric motor acts as a
generator and charges the
battery. This efficient system
therefore makes use of the
energy that would be converted
into heat during conventional
braking and stores it in the
powerful lithium-ion battery.
For longer journeys too,
Mercedes-Benz sees the fuel cell
as one of the key technologies
for zero-emission driving.
Providing a suitable network of
hydrogen filling stations is in
place, this technology offers
ideal possibilities for
sustainable mobility well into
the future. The hydrogen-powered
fuel cell combines "zero
emissions" with a long operating
range as electrical power is
generated on board during the
journey. There are no exhaust
emissions whatever, and no CO2
is emitted either. The BlueZERO
F-CELL emits nothing more than
steam. Moreover, a fuel cell
drive system is almost twice as
efficient as an internal
combustion engine.
BlueZERO with range
extender: flexible solution with
a long range
In
the third version, the BlueZERO
E-CELL PLUS, the Mercedes
engineers combine the electric
drive system from the purely
battery driven BlueZERO E-CELL
with an additional internal
combustion engine that serves as
a range extender. The compact
50-kW three-cylinder
turbocharged petrol engine from
the smart fortwo charges the
battery whilst the car is being
driven.
Advantage of the range extender:
as with conventionally powered
cars equipped with a petrol or
diesel engine, the customer
benefits from a significantly
longer range (up to 370 miles),
especially as the BlueZERO
E-CELL PLUS can also be quickly
and easily refuelled at any
normal filling station. The
customer can therefore be sure
that the car is available for
use anywhere and at any time.
And when an urban area is
reached after an overland
journey, the driver can continue
on their way under electric
power alone.
The BlueZERO E-CELL PLUS
therefore allows electric
mobility at the touch of a
button, a particular benefit in
densely populated urban areas
with environmental zones, toll
charges and other access
restrictions affecting cars with
internal combustion engines.
The BlueZERO E-CELL PLUS with
the range extender clearly
highlights the advantages of the
sandwich-floor platform: here
too, the key drive components
are integrated in the underfloor
area to save space. The internal
combustion engine is installed
near the rear axle, in the spare
wheel well. Thanks to the range
extender, the BlueZERO E-CELL
PLUS has a range of up to 370
miles, of which 93 miles are in
locally emission-free electric
mode, with no drop in
performance. The NEDC fuel
consumption is 62 mpg. In
conjunction with a plug-in
battery and the resulting CO2
bonus, the car emits just 32
grams of CO2 per
kilometre.
In
addition, the highly efficient
modular concept allows further
variants to be individually
configured. If the system is
designed appropriately, the
internal combustion engine used
as a range extender can also be
temporarily used as a direct
drive unit – when driving on
country roads, for example. This
setup leaves the full battery
capacity available for driving
in town. Other conceivable
variants might be to use the
fuel cell as a range extender,
or a combination of the fuel
cell and plug-in batteries.
Thanks to this versatility, the
Mercedes-Benz modular electric
drive concept is able to cover
every conceivable option for
electric driving.
Instead of a fuel filler cap,
the car features plug-in
connectors to EU and US
standards for rapid recharging
with electrical power. One
contact is designated for
conventional power cables that
fit any household power socket.
The second contact is suitable
for connection to public
recharging stations. |
