Hybrids: then and now

Very different from their turn-of-the-century forebears, modern hybrid electric vehicles (HEV) are almost as clean as pure EVs and have the range of conventional cars. The author discusses the advantages of HEV and describes the two basic types of HEV, parallel and serial. The serial type has a downsized engine on board that drives a generator that supplements the batteries and can charge them when they run low. In the parallel type the ICE and the electric motor can both deliver propulsion power to the wheels. The advantages of these two types of HEV are discussed. The parallel HEV is then discussed in more detail