How do solar panels work?
Solar panels convert sunlight into electricity using a process called the photovoltaic effect.
The core components of a solar panel are photovoltaic (PV) cells. These cells are typically made from semiconductor materials, most commonly silicon. When sunlight hits these materials, they absorb the energy and release electrons, which are negatively charged particles.
The Step-by-Step Process
The process of generating electricity from sunlight can be broken down into a few key steps:
- Sunlight Absorption: When the sun shines onto a solar panel, energy from the sunlight is absorbed by the PV cells in the panel. Sunlight is composed of tiny packets of energy called photons.
- Electron Excitation: These photons transfer their energy to the electrons within the semiconductor material of the PV cell. If a photon has enough energy, it can knock an electron free from its atomic bond.
- Creating an Electric Field: PV cells are constructed with layers of different semiconductor materials that create an internal electrical field. This field acts like a built-in pathway, guiding the freed electrons in a specific direction.
- Generating Current: This energy creates electrical charges that move in response to an internal electrical field in the cell, causing electricity to flow. The movement of these freed electrons in a directed manner constitutes an electric current.
- Collecting the Current: Metal contacts on the surface of the PV cell collect these flowing electrons. This direct current (DC) electricity is then channeled out of the panel.
Reference: When the sun shines onto a solar panel, energy from the sunlight is absorbed by the PV cells in the panel. This energy creates electrical charges that move in response to an internal electrical field in the cell, causing electricity to flow. (Source: Department of Energy)
From DC to AC Power
The electricity produced by a solar panel is Direct Current (DC), meaning the electric charge flows in one direction. Most homes and businesses use Alternating Current (AC) electricity, where the direction of the electric charge periodically reverses.
To make solar energy usable for most standard appliances and the electrical grid, the DC electricity from the solar panels must be converted to AC electricity. This is done using a device called an inverter.
How Solar Panels Convert Sunlight to Electricity
Here's a simplified look at the energy transformation:
| Input | Process | Output |
|---|---|---|
| Sunlight (Photons) | Absorption by PV Cell Electrons | Freed Electrons |
| Freed Electrons | Directed by Internal Electric Field | Electric Current (DC) |
| Electric Current (DC) | Conversion by Inverter | Electric Current (AC) |
In summary, solar panels work by utilizing the photovoltaic effect within their PV cells. Sunlight is absorbed, freeing electrons. An internal electric field guides these electrons, creating a flow of electricity. This DC electricity is then converted to AC electricity by an inverter for practical use.
