Energy efficiency of photosynthesis according to energy stored as carbohydrate and oxygen

Value 27 %
Organism Biosphere
Reference Robert E. Blakenship, Molecular Mechanisms of Photosynthesis, 2008 Blackwell Science pp.35 Table - link
Method Calculated according to ratio between (1)Gibbs free energy of formation for the reaction H2O+CO2>>(Glucose)/6+O2=+479.1 kJ/mole (2) Energy input from light E=(QR)*H*C*Avogadro's number/lambda. QR-Consensus Quantum requirement for oxygen production (9-10, taken as 10 for present calculation), h-planck's constant, c-speed of light, lambda=680 nm(red light).E=1761.4 kJ/mole. Ratio=479.1/1761.4=0.27. Please see table link for details
Comments In red light (680 nm). Quantum requirements of oxygenic photosynthesis as low as 3 were measured by Warburg (rather than 10 in present calculation) and give Efficiency of 91% (BNID 104626). For comparison with efficiency of semiconductor solar cell (10%) and discussion of monochromatic as opposed to broad spectrum light see bottom paragraph in table link (BNID 104628). See also efficiency of Calvin cycle based on standard free energies which is 90% (BNID 101674)
Entered by Uri M
ID 104627