Entropy Radiation and Negentropy Accumulation with Photocells, Chemical Reactions and Plant Growth

The entropy flow in solar radiation is discussed on the basis of Planck's theory of blackbody radiation. It is 133 per cent of the entropy flow in heat conduction (of the same power and temperature) and leads to a modified Carnot efficiency limit for photocells. Chemical reactions involve both entropy generation by dissipation and net stripping of structural entropy. Photosynthesis of biomatter is a chemical reaction pumped against chemical potential differences by solar radiation or photon power. It reduces the structural entropy compared to the entropy of the reacting oxides and constitutes a negentropy accumulation. The structural entropy capacity of matter is compared to a vase that changes its width during reaction. Both the entropy flow of solar radiation and the removed structural entropy are reradiated into space; in this view space is as important as solar radiation for sustaining life. In the beginning section,as a preparation to the above, the known exergy efficiency is shown to be less arbitrary than conventional efficiency and related to entropy generation or negentropy consumption