Which technology is used to convert sunlight into electricity?

Which technology is used to convert sunlight into electricity?

• A. Solar panels
• B. Wind turbines
• C. Hydroelectric dams
• D. Geothermal plants

Answer: (A)

Sunlight-to-electricity is achieved by solar panels that contain photovoltaic cells. When light hits a semiconductor such as silicon, photons transfer energy to electrons, creating electron–hole pairs. In the built-in electric field of a p–n junction, these charge carriers are pushed in a direction, producing an electric current. Collecting many cells together gives usable direct current, which can be stored or converted to alternating current for use in the grid. Other technologies listed rely on different energy sources: wind turbines use wind to turn blades and generate power, hydroelectric dams use flowing water to spin turbines, and geothermal plants use heat from inside the Earth to produce steam that drives turbines. They don’t convert sunlight directly into electricity, which is why solar panels are the correct choice.

Sunlight-to-electricity is achieved by solar panels that contain photovoltaic cells. When light hits a semiconductor such as silicon, photons transfer energy to electrons, creating electron–hole pairs. In the built-in electric field of a p–n junction, these charge carriers are pushed in a direction, producing an electric current. Collecting many cells together gives usable direct current, which can be stored or converted to alternating current for use in the grid.

Other technologies listed rely on different energy sources: wind turbines use wind to turn blades and generate power, hydroelectric dams use flowing water to spin turbines, and geothermal plants use heat from inside the Earth to produce steam that drives turbines. They don’t convert sunlight directly into electricity, which is why solar panels are the correct choice.