Hybrid cars have graced Europe's roads for a while and yet, uptake of the technology has remained weak on our Continent in recent years. Differently from North American and even more Japanese markets, estimates suggest that not more than 1% of cars in Europe are based on hybrid powertrain systems also due to the wide presence of low consumption and lower cost diesel based solutions.
Compared to conventionally powered models, list prices for hybrid cars can run as much as 40% higher in Europe. That price gap means consumers carefully weigh up the advantages of a hybrid, such as improved fuel consumption and reduced emissions and also the performance, driveability and comfort of the technology. Concurrent continuous improvements, in terms of new energy saving technologies able to reduce emissions and fuel consumption in conventional internal combustion engine powered cars can mean hybrids loose out.
While hybrid technologies are widely considered to be fairly mature (the Toyota Prius has been the highest selling car on a world-wide basis in the first quarter of 2012) and the intensity of the hybrids' positive effects is not under discussion, the lack of adoption in Europe largely depends on consumers' sensitivity to price. This is one reason why the European Commission is investing in research projects to improve performance of hybrid technologies and hopefully go some way to reduce their cost and hence increase their adoption rates.
Dr Vittorio Ravello of the Centro Ricerche Fiat in Italy coordinates one of these research and technology development projects and says that in the long run it will be strategic for Europe to lead in these technologies. "The European project level is fundamental in bringing together all the right partners and the requested competences to perform these research investigations" he says.
Involving 21 industrial and academic partners, the Highly Integrated Combustion Electric Powertrain System (Hi-CEPS) project has received a contribution of €9.9 million to evaluate the technical feasibility of novel full hybrid powertrains (which are essentially combustion engines and electric motors combined into one unit) that can offer improved fuel consumption, performance, reduced emissions in respect of currently available conventional technologies.
"We are working on three different architectures of powertrains and we are technically validating them through the development of hybrid powertrain prototypes: a gasoline based system for small cars, a natural gas based approach for mid-sized cars and a diesel based approach for light commercial vehicles. The main goal is to give practical evidence that the electric "building blocks" of these systems can be applied in different configurations, in different vehicle types and with different fuels to gain improved efficiency and reduced emissions" Ravello continues, suggesting that the modular designs should also help reduce the intrinsic extra costs of the hybridised systems.
Preliminary results from the studies suggest that benefits from the new design could be considerable.
For instance the hybridisation of a small car, with a front axle having an engine coupled with an electric machine and an electrically powered rear axle, resulted in an estimated fuel consumption reduction of around 30% in comparison to a conventionally powered version of the model with same performance. It could also run for some kilometres in pure electric mode, depending on the energy installed in the on-board high voltage battery pack.
The team also expects strong improvements in the fuel economy of diesel-powered hybrid commercial vehicles. Lab based results obtained at powertrain level suggest CO2 emissions could be reduced by around 35%. This is through the introduction of reduced engine capacity (engine downsizing), modified mechanical transmission configuration (electric dual clutch transmission) and the introduction of an integrated electric motor in order to support the acceleration phase (boosting mode) and recovering the kinetic energy in braking mode with a buffer sized battery pack.
Another configuration that is under test on a vehicle prototype includes a highly innovative and patented electromagnetic transmission, which replaces the traditional gears and clutches of a car's gearbox with two encapsulated electric motors, one inside the other. The vehicle then works with an electric system of continuous transmission ratios, meaning the engine is more efficient at all speeds. According to the tests, the system effectively contributes to the vehicle's dynamic performance (with a torque and power boost) and comfort (because there is no longer a need to shift gears). CO2 savings are in the range of 30-35%.
"We also had the opportunity to perform initial base lab research investigations of some other promising technologies for the recovery of engine exhaust gas energy and storage of thermal energy generated when the engine is running, and to be reused during the engine off phases also to improve the on-board thermal comfort", says the coordinator.
The research project is in its final stages with completion due in 2012. Ravello concludes: "The hybrid systems we have under investigation certainly can improve both the emissions and fuel consumption of a vehicle and we hope that our results will give an effective support for future developments of hybrid technologies as they move towards the industrialisation and commercialisation phases."