Hybrid Electric Bus to Run on Ethanol, Diesel, or Gasoline

Scania at fuel conference in London: Ethanol the best alternative fuel for urban transport:
Scania.com -- 3/22/2006
"...This engine is coupled to a robust generator that supplies electricity to an electrical motor that doubles as a generator when braking. Energy is stored in industrial ultracapacitors with higher power density and higher efficiency than existing batteries.
The potential fuel saving with Scania's hybrid concept is 25% or more, with correspondingly lower emissions. Scania is building the first prototype right now. The technology could be ripe for the market in five years' time."