What Is a Photovoltaic Cell (PVC)?
When thinking about solar energy, photovoltaic cells (PVC), also known as PV cells or solar cells, come to mind. The semiconductor of photovoltaic cells is usually made of silicon and generates electricity when exposed to sunlight.
It relies on the photovoltaic effect, which is the tendency of semiconductors to generate a small electric current when exposed to sunlight. PV cells are the individual units that make up solar panels and allow users to convert sunlight into electricity.
Photovoltaic cells (PVCs) are arranged in series or parallel circuits depending on the application. Its power is typically used as a supplemental or backup energy source.
Photovoltaic Cell Effect
The photovoltaic effect is the physical process by which solar cells convert light (photons) into electricity (voltage).
Photons in light are absorbed by semiconductors, causing electrons to become excited and move away from the photovoltaic cell's negative terminal. Electrons will flow through the photovoltaic cell so long as it is exposed to sunlight or other external energy sources.
The PVC cell then releases clean and quiet energy without pollutants or emissions.
How a Photovoltaic Cell Works
When photons are released and emitted by the Sun, the photovoltaic cell absorbs them and generates the flow of electrons.
When these photons are absorbed by the semiconductor of the PV cell, which has both p-type and n-type, the electrons move to the positive side (p-type) while the hole moves to the negative side (n-type).
This causes the opposite movement of the negatively charged particle and the positively charged particle. It then flows to the external circuit in an electrical energy form, which produces a direct current.
Photovoltaic Cell Efficiency
Photovoltaic cells' efficiency is measured using the "efficiency ratio", representing how much sunlight hits the surface and generates electricity.
The most efficient photovoltaic cells have an efficiency ratio of around 33 percent, referred to as the Shockley-Queisser limit.
What Is a Photovoltaic Cell System?
Photovoltaic systems are used for non-polluting, alternative energy generation that does not use chemicals or fuels. They produce no waste and represent an inexhaustible source of energy.
A basic PV system comprises the following components:
Solar Panels
Collect visible light from the Sun and convert it to electricity. The type of electricity current solar panels use is direct current (DC).
Charge Controller
This is an important layer of PV cells since it controls the amount of electricity being transmitted in the batteries.
This means that it ensures that the batteries of the PV cells are prevented from storing an excessive amount of energy to avoid overcharging.
Rechargeable Batteries
These are the secondary power sources for photovoltaic systems. Their purpose is to store excess energy from photovoltaic cells to use at any time.
Power Inverter
It converts direct current (DC) provided by photovoltaic cells into alternating current (AC), needed for appliances at home and in businesses.
Types of Photovoltaic Cell
Monocrystalline Silicon Cell
Monocrystalline photovoltaic cells have a long history of successful use in Earth-orbiting spacecraft.
They are typically made from a single crystal or monocrystalline and can be mass-produced with high yield. Monocrystalline photovoltaic cells consist of large, highly ordered grains that provide excellent electronic properties.
Polycrystalline Photovoltaic Cells
Polycrystalline photovoltaic cells comprise several small crystals or grains.
They are more efficient at high temperatures and have a higher current rating than monocrystalline photovoltaic cells.
Thin-Film Cells
It is possible to use thin layers of semiconductor material on a substrate, such as glass or plastic.
Although thin-film photovoltaic cells are less efficient than monocrystalline or polycrystalline photovoltaic cells, they are lighter and more flexible.
They can be produced at a low temperature on a continuous roll-to-roll process that makes them ideal for roofs, building facades, cars, planes, boats, and other structures where weight is an issue.
High-Efficiency Cells
High-efficiency photovoltaic cells are typically made from III-V compound semiconductors, such as gallium arsenide (GaAs), instead of silicon.
GaAs photovoltaic cells are generally more expensive to manufacture than silicon photovoltaic cells, but they can be efficient enough to justify the cost.
Layers of Photovoltaic Cells
Since a PV cell is a system, it comprises different layers.
Semiconductor Layer
This layer is made of silicon. Photons with enough energy release electrons from atoms, which generate electrical current.
Conducting Material Layer
This layer is made of metal. It allows electrical currents to flow between all the cells in a PV circuit.
Anti-Reflection Coating Layer
Photons that bounce off or get reflected by the PV cell do not contribute to electricity generation, so the coating reduces reflection and increases efficiency.
Advantages and Disadvantages of PVC
There are several advantages and disadvantages of using PV cells.
Advantages
- They have modular features
- They can generate electricity at the point of use
- They require minimal maintenance
- They release clean and quiet energy without any non-pollutants
- They are a great option for electricity supply in developing countries where there is abundant sunlight and a largely rural population without the proper infrastructure to develop an electrical grid
- They are not restricted by size and can be made as large as desired
- They do not require fuel to be burned
- They provide a renewable source of energy
Disadvantages of Photovoltaics
- They are not suitable for water heating or other heat-related appliances
- They are complex and tricky to install
- They are expensive to install
- The presence of clouds can affect electricity generation adversely by reducing the amount of sunlight reaching photovoltaic cells
The Bottom Line
Photovoltaic cells are devices that absorb the energy of photons and convert it into electricity.
There are three types of photovoltaic cells: monocrystalline, polycrystalline, and thin-film.
A photovoltaic cell is made up of layers comprising the semiconductor layer, the conducting material layer, and the anti-reflection coating layer.
Based on the advantages and disadvantages of photovoltaics, it can be concluded that a PV cell, as an alternative energy source, is very promising.
However, photovoltaic systems are expensive to install, so they need to have proper incentives supported by governmental policies in order to become more economical in their application.
FAQs
1. What is a photovoltaic cell (PVC)?
Photovoltaic cells are PV modules that generate electricity when photovoltaic modules are illuminated with sunlight. Photovoltaic cells can be connected to form photovoltaic modules, which are installed in photovoltaic power packs for homes and businesses.
2. What is a photovoltaic system?
A photovoltaic system is a photovoltaic power pack for homes and businesses. Photovoltaic systems have photovoltaic cells connected to photovoltaic modules, which are connected to photovoltaic power packs that can power entire buildings.
3. How does a photovoltaic cell work?
Photons from sunlight excite photovoltaic cells, which create electricity. Photovoltaic cells can generate electricity for an entire building using photovoltaic modules connected to photovoltaic power packs.
4. What is a photovoltaic power plant?
A photovoltaic power plant generates electricity from photovoltaic cells. Photovoltaic power plants are large or small, depending on usage and energy requirements.
5. How are photovoltaic cells made?
Photovoltaic cells are modules made of wafers with photovoltaic layers.
