Hybrid Vehicles

A hybrid vehicle has three major systems -
1. A primary power source, either an IC engine driven generator where the IC engine only operates in the most efficient part of it's performance map, or alternatives such as fuel cells and turbines.
2. A power storage unit, which can be a flywheel, battery, or ultracapacitor. A drive unit, almost always now an electric motor that can used as a generator during braking. Regenerative braking may increase the operational range about 8-13%.
3.Battery technology has not yet advanced sufficiently to economically substitute for an IC engine, while retaining the carrying capacity, range, performance, and driveability of the vehicle.
Hybrid vehicles may enable this problem to be at least partially overcome, but they remain expensive, and the current ZEV (Zero Emission Vehicles) proposals exclude fuel cells and hybrids systems, but this is being re-evaluated