The photovoltaic panel and electric car system is 40 times (BTL) to 100 times (biodiesel) more efficient compared to the system of energy crops plus a biofuel driven car! That is one reason why the nova-Institute thinks that biofuels are an intermediate technology that should be substituted by solar (and wind) energy in the next 20 – 30 years. To switch from biomass to solar will set free huge amounts of land. We should rather use biomass for bio-based chemistry and materials which cannot be produced by sun and wind.
You can download the full article at www.bio-based.eu/ecology