How does photosynthesis store solar energy as chemical energy?

Photosynthesis stores solar energy as chemical energy through a light-energized oxidation-reduction reaction that occurs in two primary stages.1

The Light Reactions

The process begins when chlorophyll and other pigments absorb light energy, which is funneled into reaction centers. This energy drives the oxidation of water, splitting it into oxygen, hydrogen ions, and electrons. As electrons move through transport chains, they create a charge difference across the thylakoid membrane, functioning similarly to a battery. This phase results in the synthesis of ATP and NADPH, which serve as high-energy carriers.231

The Dark Reactions

In the subsequent "dark" reactions, the energy stored in ATP and NADPH is utilized to reduce carbon dioxide into organic carbohydrates, such as glucose. This assimilation of inorganic carbon into stable organic compounds effectively locks solar energy into chemical bonds that sustain the plant and the organisms that consume it.123