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Solar energy is harnessed from the sun’s constant nuclear fusion reactions deep within its core. These reactions occur when protons, akin to hydrogen atoms, collide and fuse under intense temperatures and pressure, producing helium and emitting a vast amount of energy, along with additional protons. The sun’s core, which reaches temperatures of approximately 27 million degrees Fahrenheit, continuously releases this energy in the form of electromagnetic radiation (EMR), including photons that travel to Earth.
The Functioning of Solar Panels: The Photovoltaic Effect
Solar panels operate by converting sunlight particles, or photons, into electricity through a process known as the photovoltaic effect. Discovered by Edmond Becquerel in 1839, this effect is a property of certain materials, called semiconductors, which generate an electric current when exposed to sunlight.
The photovoltaic effect involves several key steps
Sunlight energizes electrons within solar cells, initiating their movement.
The energized electrons flow out of the cell junction, creating an electrical current.
Metal plates and wires capture this electron flow, generating usable electricity.
Solar cells, typically made of silicon, serve as the building blocks of solar panels. Silicon, a semiconductor, absorbs and converts sunlight into electricity. Positive and negative doping agents, such as phosphorus and boron, are applied to create an electric field within the silicon layers, facilitating electron movement and current generation.
While silicon dominates the solar cell market, alternative materials like cadmium telluride and copper indium gallium selenide are used in thin-film solar panels for lightweight and flexible applications. Additionally, organic and perovskite solar cells offer alternative solutions, with perovskite cells demonstrating high efficiency in converting light into electricity.
Components of Solar Panels
Apart from solar cells, solar modules feature essential components:
- Glass casing: Provides durability and protection for silicon PV cells.
- Insulation layer and back sheet: Shield against heat dissipation and humidity, maintaining panel efficiency.
- Anti-reflective coating: Enhances sunlight absorption, optimizing cell performance.
Solar panels are typically categorized as monocrystalline or polycrystalline based on their silicon cell formation. Monocrystalline cells, composed of a single silicon crystal, offer higher efficiency than polycrystalline cells, albeit at a higher cost due to their superior electron mobility.
In summary, solar energy relies on the sun’s nuclear fusion reactions to produce electricity through the photovoltaic effect, with solar panels comprising various components to harness and convert sunlight into usable power.
