Volvo is unveiling an innovative plug-in
hybrid at the Frankfurt Motor Show. The ReCharge Concept is a specially
designed Volvo C30 with individual electric wheel motors and batteries
that can be charged via a regular electrical outlet. When fully charged
the Volvo ReCharge Concept can be driven approximately 62 miles on
battery power alone before the car’s four-cylinder 1.6 Flexifuel engine1
is needed to power the car and recharge the battery. The concept car
also retains the Volvo C30’s lively and sporty drive thanks to an
acceleration figure of 0-62mph in 9 seconds and a top speed of 100mph.
“This is a groundbreaking innovation for
sustainable transportation. This plug-in hybrid car, when used as
intended, should have about 66 percent lower emissions of carbon dioxide
compared with the best hybrid cars available on the market today.
Emissions may be even lower if most of the electricity comes from CO2-friendly
sources such as biogas, hydropower and nuclear power. A person driving
less than 60 miles per day will rarely need to visit a filling station.
Also, thanks to the excellent electrical range from a fuel consumption
angle, the Volvo ReCharge Concept is exceptionally kind to the car
owner’s wallet,” commented Magnus Jonsson, Senior Vice President
Research & Development at Volvo Cars.
Operating costs are estimated to be
about 80 percent lower compared to a similar petrol-powered car when
using battery power alone and even drivers who cover more than the
battery-only range will benefit from the ReCharge Concept. For a 150km
(93 mile) drive starting with a full charge, the car will require less
than 2.8 litres of fuel, giving the car an effective fuel economy of 1.9
The only extra cost will be the
electricity used during charging. The Volvo ReCharge Concept can be
charged at any regular electric plug socket at convenient locations such
as at home or work and a full recharge will take three hours. However,
even a quick one hour charge provides enough power to cover just over 30
During a journey the combustion engine
starts up automatically when 70 percent of the battery power has been
used up. However, the driver also has the option of controlling the
four-cylinder Flexifuel engine manually via a button in the control
panel. This allows the driver to start the engine earlier in order to
maximise battery charge, for instance when out on a motorway in order to
save battery capacity for driving through the next town.
An electric motor at each wheel
The Volvo ReCharge Concept combines a number of the latest technological
innovations into a so-called “series hybrid” where there is no
mechanical connection between the engine and the wheels.
- The battery pack integrated into
the boot uses lithium-polymer battery technology. The batteries are
intended to have a useful life beyond that of the car itself.
- Four electric motors, one at each
wheel, provide independent traction power.
- Four-cylinder 1.6-litre Flexifuel
engine drives an advanced generator that efficiently powers the
wheel motors when the battery is depleted.
“There is a considerable difference
between the Volvo plug-in hybrid and today’s hybrids. Today’s hybrids
use the battery only for short periods to assist the combustion engine.
Volvo’s solution is designed for most people to run on electric power
all the time, while providing the extra security that comes with having
a combustion engine as a secondary source of electrical power,” says
Ichiro Sugioka, project manager for the Volvo ReCharge Concept.
Electric car with a combustion
engine as backup
The Volvo ReCharge Concept is a battery electric car with an efficient
generator, an Auxiliary Power Unit (APU), that steps in when battery
charge becomes insufficient for adequate driving performance. The APU is
designed to distribute electrical power to the individual motors at each
wheel. Since the combustion engine only powers the APU, it can operate
in an optimal fashion, both for regulated emissions and CO2.
The APU is powerful enough to supply an entire house with electricity.
For example it could, in principle, with minor modifications, give the
car owner an electricity generator right at his front door in the event
of a power failure.
Specially developed electric
The central electrical components in the Volvo ReCharge Concept – the
generator for the APU and the wheel motors – were developed together
with British electromagnetic specialists PML Flightlink.
With an individual electric motor at
each wheel, weight distribution as well as mechanical efficiency and
traction are maximised and the friction in mechanical gears is
eliminated. Since the car does not have the transmission found in
ordinary cars, there is no need for a gear lever.
To help maximise the environmental
benefits, the Volvo ReCharge Concept has high-efficiency tyres developed
by Michelin which are specially designed to accommodate the wheel
motors. The car also has All-Wheel Drive in the truest sense of the term
as power to each wheel is controlled individually.
The energy that is generated during
braking is transmitted to the battery pack. When the system is
ultimately developed, traditional wheel brakes will be completely
replaced by electrical brakes with minimal energy wasted through
friction. To ensure reliable operation of the drivetrain and braking
system, driver inputs are fed into a quadruple-redundant electronic