Solar power generation is mainly achieved in two ways: photovoltaic power generation and solar thermal power generation. These two technologies use different aspects of sunlight to generate electricity.
Photovoltaic power generation is the most common form of solar power generation, which directly converts sunlight into electricity. This process is achieved through the use of solar panels, which usually consist of multiple solar cells, and relies primarily on the photoelectric effect. Solar cells are typically made of semiconductor materials such as silicon, which are able to absorb sunlight and convert it into electricity.
Absorbs light energy: When sunlight hits a solar panel, the semiconductor material absorbs the photons (the basic unit of light) in it.
Excite electrons: The energy of the photon releases the electrons inside the semiconductor from its atoms, creating free electrons and holes.
Generate an electric current: An electric field is set inside the battery so that the excited electrons move in one direction and the holes move in the other, thus forming an electric current.
Output power: Through an electrical wire connected to the battery panel, the current is directed to the inverter, which converts direct current into alternating current for use in the home or grid.
Solar thermal power generation uses sunlight to generate heat energy, which is then converted into electricity. This method typically involves using mirrors or lenses to concentrate sunlight, heat the fluid to produce steam, and then use the steam to propel a turbine generator to generate electricity.
Concentrate the sun's rays: Use a series of mirrors (such as parabolic mirrors) or lenses to concentrate sunlight into a small area.
Produces high temperatures: Concentrated sunlight heats a fluid (such as water, oil, or salt solution), creating high temperatures.
Vapor is generated: High-temperature fluids are used to produce steam.
Power generation: Steam drives the turbine to rotate, which in turn drives the generator to produce electricity.
Cooling cycle: The steam is cooled in the condenser and converted back to water, which is reheated to form a closed cycle.
Solar power is a clean, renewable energy source that has the potential to significantly reduce dependence on fossil fuels and reduce greenhouse gas emissions. Although solar power is less efficient at night or in cloudy weather, it is still seen as an essential part of sustainable energy solutions in many regions.