Figure 1. About 78% of photosynthetically active radiation (PAR) falling on a leaf is absorbed, while the rest is reflected or transmitted. The result of this solar broadband filtering is that ≤ 30% of incident light is available to drive photosynthesis. Photochemical inefficiency, photonic mismatch, and metabolic overhead further whittle quantum efficiency of photosynthesis conversion of solar energy to biomass down to 0.5-1.3% at mid-latitude when averaged over the whole year (Bisio and Bisio, 1997). Image adapted from ESA Bull. 116, 2003.