The use of vegetal biomass for energy production has nowadays become problematic due to the competition of sustenance and foraging, as most of the energy crops can only be grown on lands suitable for agricultural cultivation. Therefore, only those crops are feasible for energetic biomass production, for which there is only moderate demand for sustenance (e.g. millet). The cultivation of algae has a number of advantages in comparison with plant cultivation. Algae cultivation does not need arable lands. In addition, a higher growth rate can be achieved than with terrestrial planting.