Photosynthesis is used by plants to harness solar energy. A semiconductor-based solar cell harnesses solar energy to convert it to electricity required by humans.
A leaf can capture sunlight using its green pigment called chlorophyll which is located in the chloroplasts, tiny organelles found inside the cells of plants, mainly in the leaves. Once sunlight has been absorbed, the energy is used for the process of photosynthesis. Carbon dioxide enters the leaf through tiny pores known as stomates and water is transported to the leaf through vascular tissue known as xylem cells located in the veins of plants. These react to form glucose, a simple sugar and water vapor, oxygen gas and A.T.P. for the cell to use as energy. The glucose molecule contains stored chemical energy which can be used by living things that consume plants as food energy. A solar or photovoltaic cell made of a silicon wafer, captures energy from the sun, much like a green plant. It can then convert it to electrical energy. Certain materials have the photoelectric effect, which means that as they absorb photons of light, they release electrons. These electrons can be used to produce an electric current. Since energy can be transformed from one form to another, in plants, light energy is transformed into chemical energy and in a photovoltaic cell, light energy is transformed into electrical energy.