Photosynthesis is incredibly efficient
Tracing back along the food web, most of the energy organisms need to survive originates with the Sun. Green plants, cyanobacteria (also known as blue-green algae), and other organisms capture photons and use them to drive the chemical reactions of metabolism. Photosynthesis is incredibly efficient: nearly 100 percent of the energy from the photons absorbed by the photosynthetic machinery is transferred to the chemical reaction center.
A set of chemistry experiments that began in 2007 showed that this efficiency may be due to quantum mechanics. The data demonstrated coherence between the electrons in the various pigment molecules during the transfer process, meaning that the states of the electrons were coordinated and they acted as a single system, even though they resided in different atoms.
Source: Schrödinger’s gardenia: Does biology need quantum mechanics?