How can sunlight drive chemical reactions that store energy?

Sunlight drives chemical reactions that store energy primarily through the process of photosynthesis. In this process, green plants, algae, and certain bacteria convert solar radiation into energy-rich chemical compounds like glucose.1

The mechanism functions as follows:

• Light Harvesting: Specialized pigments, such as chlorophylls and carotenoids, act as an antenna to absorb sunlight and direct excitation energy to a reaction centre.1
• Charge Separation: Within the reaction centre, the absorbed energy triggers a charge-transfer reaction where an electron is moved from a chlorophyll pair to an adjacent molecule.1
• Energy Storage: This electron transport, coupled with the movement of hydrogen ions across a membrane, creates a charge difference. This functions similarly to a battery, storing electrical energy that is subsequently used to synthesize high-energy organic molecules.1

While photochemical reactions can also initiate processes like the breakdown of ozone in the atmosphere, photosynthesis is the primary biological method for capturing and storing solar energy in chemical bonds.12