Energy, when examined as meaning, is defined as the ability to perform work. Energy consumption in our country and worldwide, along with population, has been rapidly increasing over time. This rise is driving an urgent need for cleaner and more environmentally friendly energy sources beyond conventional fossil fuels. All nations are striving to increase clean energy production and are being compelled to reduce greenhouse emissions. Solar panels, developed in this context, are devices that directly convert solar energy into electricity energy. The first known use of solar energy dates back to 205 BCE, when Archimedes focused sunlight onto enemy ships to set them ablaze during a siege. Although solar energy was utilized in ancient times, its modern application began in the 18th century. Although research experienced a fifty-year pause after 1914, the first industrial-scale type energy production was carried out in Los Angeles in 1984 by Luz Corporation.
Applications
When examined in our country and world, solar energy is the source with the highest potential and usage rate. Converting solar energy into electricity helps meet energy demands across numerous sectors.
- Residential Buildings: Solar panels reduce energy costs and help lower household electricity expenses. Rooftop solar panels assist in meeting the electricity needs of homes and allow excess electricity to be sold back to the grid through opportunity.
- Commercial Buildings: In offices and commercial structures, solar panels are used to reduce operational costs and minimize carbon foot footprints, similar to residential applications.
- Agriculture: Solar energy is used to power irrigation systems. When applied in greenhouse like structures, it can significantly enhance efficiency.
- Remote and Rural Areas: Due to limited or difficult access to the electrical grid, solar energy is often preferred in rural regions. It enables electricity generation independent of the grid to meet local needs.
- Electric Vehicles: When used in vehicle charge stations, solar panels can provide a cost-free charging solution for vehicles.
- Mobility Applications: Similar to rural areas, there are practical portable applications where access to electricity is difficult or where establishing a fixed system is impractical.
This potential and versatility will make solar panels more sustainable and common in the future.
Structure
The fundamental component of solar panels is photovoltaic (PV) cells. Solar panels consist of four main components: photovoltaic material, electrical connections, protective covering, and backsheet.
- Photovoltaic Material: The most critical part of solar panels, photovoltaic material is typically silicon-based. This material acts as a semiconductor capable of absorbing sunlight and converting it into electrical energy. Silicon cells come in two main types: monocrystalline and polycrystalline. Monocrystalline cells offer higher energy efficiency, while polycrystalline cells are more cost-effective.
- Electrical Connection Components: Metal conductors are used to facilitate the flow of electricity between PV cells. These conductors, usually made of silver or copper wire, enable the connection of cells and allow the collected electricity to be directed efficiently.
- Protective Glass: A specialized type of glass that protects the front surface of solar panels. This glass is manufactured using materials with high transparency and UV resistance to enhance panel efficiency and durability.
- Backsheet: The component that covers the rear side of the solar panel. Made from Plastic or composite materials, this building protects internal components from external factors while also providing overall structural stability.
The efficiency of solar panels depends on various factors including the materials used, cell design, and work conditions. Thanks to technological advancements, the efficiency of solar panels is continuously improving, and efforts to reduce their cost are ongoing.
Working Principle
Solar panels are devices that convert sunlight into electrical energy through the photovoltaic effect. The photovoltaic effect occurs when photons of light striking a semiconductor material excite electrons, freeing them and raising their energy levels. These freed electrons complete a circuit to generate an electric current.
The core components of solar panels are typically silicon-based photovoltaic cells. These cells create an electric field through the junction of N-type and P-type silicon, known as a p-n junction. When sunlight hits the cells, the electric field directs the freed electrons, producing an electric current. The electricity generated is usually in the form of direct current (DC) and must be converted to alternating current (AC) before being connected to the grid.
Types
Solar panels are classified into different types based on the materials used and their structural characteristics:
- Monocrystalline Solar Panels: Manufactured from a single crystalline structure, they offer high efficiency, typically ranging from 15% to 22%. Their ability to generate more energy in less space makes them preferred in areas with spatial constraints.
- Polycrystalline Solar Panels: Composed of multiple crystals, they have lower efficiency compared to monocrystalline panels (approximately 13% to 17%). However, their lower production cost makes them an economical alternative.
- Thin-Film Solar Panels: Lightweight and flexible, these panels are produced using various materials such as cadmium telluride or CIGS. Their efficiency typically ranges from 10% to 12%. Due to their reduced material usage, their applications are expanding.
- Transparent Solar Panels:These panels, which allow sunlight to pass through while simultaneously generating electricity, are particularly favored in window, façade, and greenhouse applications due to their ability to be integrated into glass surfaces. They are expected to play a significant role in future architecture by combining aesthetics with functionality. Their efficiency generally ranges from 5% to 10%, though this is increasing with technological progress and expanded applications. The selection of a solar panel should be based on factors such as efficiency, cost, space limitations, and intended use.
