1. Field of the Invention
The present invention relates to a system and method for generating electricity from the exhaust gas of an internal combustion engine. Preferably the engine is a piston engine. The engine may be the engine of a vehicle, for example the main drive engine for a land, air or water vehicle or a “range extender” engine for a hybrid internal combustion/electric vehicle, or it may be a non-vehicle engine such as a static engine to power an electric generator set.
2. Description of the Related Art
It is known to generate electricity using a generator that is driven by a turbine that is in turn driven by the exhaust gas from an internal combustion engine of a vehicle. For example, US 2011/0018267 discloses a hybrid vehicle in which the exhaust gas from a diesel engine powers an exhaust turbine generator. In order to avoid the weight of batteries carried in the vehicle, for storing the electricity generated in this way, the electricity is used to drive an electric motor of the hybrid vehicle, and a bypass gate is provided so that if the generator produces more electric power than can be used by the electric motor, the bypass gate is opened so that exhaust gas bypasses the turbine, and therefore excess electricity is not generated.