Volvo calls them ‘Range Extenders’ but in essence they are petrol/electric hybrids with ultra low emissions.
The Volvo Car Corporation project has the backing of the Swedish Energy Agency and the EU and encompasses three potential technology hybrids, which will begin testing early in 2012.
Volvo’s Derek Crabb, Vice President Powertrain Engineering says,
"This is an exciting expansion of our increasing focus on electrification. Battery cost and size means that all-electric cars still have a relatively limited operating range. With the Range Extender, the electric car has its effective range increased by a thousand kilometres - yet with carbon dioxide emissions below or way below 50 g/km,"
Volvo will test three different hybrid combinations that will pair electric drive to the front wheels with versions of a three-cylinder petrol engine. These engines will be able to run on both petrol and E85 ethanol.
At least two of the test vehicles will be based on Volvo’s current C30 Electric and in both cases the battery pack has been reduced in size to accommodate the combustion engine and fuel tank.
Volvo Electric Car Concept l: Volvo C30 with Series-connected Range Extender
The idea is to pair the C30’s 82kW electric motor with a three-cylinder combustion engine that produces 45 kilowatts, which is also connected to a 40 kW generator. Essentially, the power generated by the generator drives the electric motor.
With the inclusion of a 40-litre fuel tank, the C30 Electric has extended range of 1000 kilometres beyond its all-electric range of just 110 kilometres.
Volvo Electric Car Concept ll: Volvo C30 with Parallel-connected Range Extender
This concept still uses a three-cylinder combustion engine, but this time it’s turbocharged and produces 141 kW, which drives the rear wheels through a six-speed automatic transmission. The key difference here is that it’s a parallel connection as opposed to a series connection.
The combination not only provides greater fuel efficiency for extended highway travel, but performance is substantially lifted with 0-100km/h acceleration times of under six seconds.
Again, the Range Extender increases the electric car’s range by more than 1000 kilometres above the battery pack only range of 75 kilometres.
Volvo Electric Car Concept 3: Volvo V60 with Parallel-connected Range Extender
Different again is what Volvo calls the Technical Concept lll whereby the complete hybrid drive package is installed under the bonnet. It’s still the same combination of three-cylinder petrol turbo combustion engine and 80-kilowatt electric motor, but with a two-stage automatic transmission driving the front wheels. The combustion engine is activated at higher speeds with this configuration and at speeds up to 50km/h power will rely solely on the electric motor.
The driving range is also extended by more than 1000 kilometres above the 50 kilometre electric only range.
These are no doubt exciting days for Volvo and indeed the hybrid world. It will be interesting to see these concepts become a useable and practical reality, in the not too distant future.