Also the Volt was 3 times on the General Motors fair booth
One open show car to show the technic with an petrol engine range extender
One open show car to show the technic with hydrogen and fuel cells range extender
My theory about biomass and plug-in-hybrid cars had been:
There is as much biomass as necessary to mix fossile fuel with 20% fuel from biomass.
When a plug-in hybrid vehicle drives 80% with batteries, there is enough biomass to produce fuel for the last 20%
But it seems that there is not so much biomass available. So in the long run, hydrogen by solar electric power could outperform biomass, even when the full hydrogen cycle needs 4 times more electric power than just to charge a battery.
So I think the most important car concept is the range extender for the electric car.
GM showed Diesel, gasoline and hydrogen as 3 different powered range extenders.
All 3 have one fact in common: drving beyond the electric mode range is more expensive than driving short distances
