A good exemple is synthetic fuel: in Germany, they have really hard issues on biomass collect which is needed for "green fuel". As of today, synthesis come from coal. And we're talking about Germany,not France.
France, who would need to triple its production of electricity to replace its oil consumption from cars.
and I did not talked about the cropland needed for "biogas" and ethanol fuel. concrete, steel, agro-industry too...the list is long.