Mobility Demands and Primary Energy Resources

Electricity production from biomass (direct combustion or derived by biofuels) presents some advantages very low cost of the starting material with respect to fossil fuels, zero net CO2 emissions, security of supply and reduction of transport distances when electricity is produced close to the biomass production site. 

However, from the efficiency point of view, it has to be considered that the biomass formation always requires the conversion of solar energy to some type of biomaterial, and this can be realized only by the photosynthesis process, whose energy efficiency is lower than 1% (see Sect. 1.3). 

The commercial nuclear technology is stiU based on fission of isotope 235 of uranium ( U). This is defined as fissile material since it is capable to absorb neutrons of any kinetic energy (also low energy thermal neutrons). Uranium is mainly present in natural deposits as U Ox, where 0.7% of uranium is constituted by the remainder being In order to have an amount of fissile nuclei 

The fission of one nucleus of produce about 200 MeV of usable energy, to be compared with 4 eV produced by the oxidation of one C atom. During the overall process, a huge amount of heat is produced through a controlled nuclear chain reaction in a critical mass of fissile material. Potential future developments (fission in fast neutron reactors (breeders), also known as fourth generation nuclear, which 

1 Possible Routes Towards Carbon-Free Vehicles 

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