This editorial in the famous sientific-journal Angewandte Chemie by Michel Hartmut, who won his nobel prize for key work in the field of photosynthesis, is an excellent summary on the issue.
...Taken together, the production of biofuels constitutes an extremely inefficient land use. This statement is true also for the production of bioethanol from sugar cane in Brazil.
...Recommendations
Because of the low photosynthetic efficiency and the competition of energy plants with food plants for agricultural land, we should not grow plants for biofuel production. The growth of such energy plants will undoubtedly lead to an increase in food prices, which will predominantly hit poorer people. The best use of the biomass lies in its conversion into valuable building blocks for chemical syntheses. Usage of the available biomass for heating purposes or for generating electricity in power stations, thus replacing fossil fuels, is preferable over biofuel production. The saved fuels can be used for transportation purposes.
Clearing rainforests in the tropics and converting them into oil palm plantations is highly dangerous because the underlying layers of peat are oxidized and much more CO2 is released by the oxidation of organic soil material than can be fixed by the oil palms. The rainforests possess an important role for the climate and constitute a valuable resource for novel compounds for drug discovery. With respectto the carbon footprint, it would be even much better to reforest the land used to grow energy plants, because at a 1% photosynthetic efficiency, growing trees would fix around 2.7 kg of CO2 per square meter, whereas biofuels produced with a net efficiency of 0.1% would only replace fossil fuels which would release about 0.31 kg CO2 per m² upon combustion!
To come back to our old Saudi discussion their pricing policy gets even more criminal. We in snowy parts of the world suffer from a lower solar energy input, especially in the winter. Our batteries suffer from the cold and we need to heat our cars. This makes the economics of the combination less attractive*. The Saudis have far more energy input by the sun per m², hardly any opp. costs for that land use and in general suffer far less battery drain due to cold and do not need a similar of heating.The [Green] Alternative
Commercially available photovoltaic cells already possess a conversion efficiency for sunlight of more than 15%, the electric energy produced can be stored in electric batteries without major losses. This is about 150 times better than the storage of the energy from sunlight in biofuels . In addition, 80% of the energy stored in the battery is used for the propulsion of a car by an electric engine, whereas a combustion engine uses only around 20% of the energy of the gasoline for driving the wheels. Both facts together lead to the conclusion that the combination photovoltaic cells/electric battery/electric engine uses the available land 600 times better than the combination biomass/biofuels/combustion engine.
The future of our individual transport has to be electric!
A car gets heated by the thermal energy which is 'lost' to it's propulsion. This reduces it's efficiency gap compared to an electric car.
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