Volvo, Range Extender (REX) for Automotive
PowerCell and Volvo Cars have performed a prestudy on a 20 kW Range Extender for electrical cars. In phase two, a Volvo XC90 is now being planned with a fuel cell.
A Range Extender offers all of the advantages of a pure electric car combined with the range of a conventional car if the hydrogen tank is adequately dimensioned. Once the car’s battery has been discharged to a predetermined level, the fuel cell automatically kicks in. The built-in fuel cell converts the H2 to electric energy which is supplied to the battery so that the driver can continue his or her journey. The car is powered by the electric motor and the average power output is provided by the fuel cell to keep the battery charged. The battery contributes maximum power, such as when overtaking. For the driver, this means that the car always achieves the same performance.
With hydrogen gas, it is possible to fill the hydrogen tank in just a few minutes instead of being subjected to long charge times. The major environmental gain lies in the absence of emissions, with water being the only end product; there are no other emissions. If the hydrogen gas is also produced with regenerative electricity from renewable sources, carbon dioxide-free vehicle transport can thereby be realized. Another advantage is that the surplus heat can be used in the winter time.