How Do Solar Panels Convert Light Energy Into Electrical Energy?

November 1, 2023
Solar energy has emerged as a leading contender in an era where sustainable and renewable energy sources have assumed critical importance. Solar energy has expanded dramatically since its inception in the middle of the 20th century; it now supplies power to residences, enterprises, and even industrial facilities on a global scale. The inaugural solar panels, which successfully converted a satisfactory amount of sunlight into electrical energy, were unveiled by Bell Laboratories in 1954. It was the beginning of something very extraordinary. Nowadays, the worldwide market for solar energy is predicted to reach $223.3 billion in 2026. It is expanding at a CAGR of 20.5%, according to PR Newswire. easy schematic converting of solar energy into electricity

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Solar panels, which transform light energy into electrical energy, are at the heart of this revolution. This phenomenon, referred to as the photovoltaic effect, has enabled the commercialization of solar energy. It is a scientific and engineering marvel. According to Wood Mackenzie, the average annual growth rate of solar panel installations worldwide will be 6% between 2022 and 2032. By 2032, the total annual capacity is projected to reach 350 GWdc, up from 251 GWdc in 2023. In light of ongoing environmental challenges, the significance of solar energy has become increasingly critical. Gaining comprehension of its functioning not only imparts clarity on the technology but also emphasizes the criticality of its broader implementation. The intriguing process by which solar panels convert solar energy to electrical energy will be explored in this article. It will illuminate the complexities of the photovoltaic effect, the solar energy materials utilized, and the future viability of solar energy as a power source.
Popular Myths About Solar Panels Busted 5

Structure of Solar Panel

Solar cells, which are also known as photovoltaic cells, are indispensable in the process of transforming solar energy into electrical energy. Critical to the operation and effectiveness of these cells is their structure. The structure of the solar panel is as follows:
  • Superconductors, commonly composed of silicon, one of the most prevalent elements on the planet, comprise the core of solar cells. A positive-negative (P-N) junction is critical for harnessing solar energy into electrical energy. To accomplish this, silicon is “doped” with other elements within the solar cell.
  • Phosphorus doping induction generates an electric charge in the emitter, the uppermost layer of a solar cell. Borosium is utilized to introduce a positive charge into the base, which is the lowest layer. The P-N junction, which converts solar energy to electrical energy, is situated between these two layers.
main components of a solar panel

Source: Dreamstime

  • Silicon electrons become energized when exposed to sunlight, impacting a solar cell. Electrons traverse the P-N junction barrier and migrate from the negatively charged emitter to the positively charged base due to the energy supplied by the sun. An electric solar system current results from this motion of electrons.
Numerous solar cells are interconnected to form solar panels. More solar energy can be converted into electrical energy as the number of cells in a panel increases. Approximately 250 to 400 volts of power can be generated by a standard solar panel. Nevertheless, this may differ depending on the solar panel’s energy input and the efficiency of its cells. Subsequent to the generation of sun electricity, a metal layer envelops each solar cell beneath a protective material, which is frequently glass. Later, for increased stability, the entire panel is encased in aluminum.

What Are Solar Panels and How They Absorb Light Energy?

Photovoltaic (PV) panels, which are solar panels by another name, are apparatuses that target and assimilate sunlight. Their principal operation is to convert solar energy, which is classified as a renewable energy source, into electrical energy that can be utilized. These panels—which are typically mounted on rooftops or other sun-exposed surfaces—represent a sustainable and environmentally friendly approach to energy generation. solar absorption

Source: SolarSquare

To what extent do solar panels harness the energy of light? The sun is the origin of everything. The Department of Energy estimates that the Earth receives around 173,000 terawatts of solar energy continuously, an amount that exceeds 10,000 times the global energy consumption of the planet. The basic steps in the process of solar energy absorption by solar panels:
  • Sunlight Hits the Solar Panel. Photons, which are light particles, initiate the process when they interact with the solar panel’s surface. Coated with a semi-conductive substance, silicon, the solar cells comprise the panels. This substance is critical due to its composition, which enables it to assimilate sunlight efficiently.
  • Energy Abstraction. The photons’ energy is absorbed by the silicon atoms when sunlight strikes the solar cell. The silicon atoms’ electrons become more mobile as a result of this energy, which stimulates them.
  • Electron Motion Generation: An electric field traverses the cells as a result of the electrons’ motion. Conducting the electrons in the desired direction, this electric field functions as a highway.
Noting that solar panel absorption of solar energy can vary in efficacy is essential. Commercial solar panels demonstrate an average conversion efficiency of 15–20 percent of the sunlight that they absorb into electrical energy. However, this rate of efficiency improvement is ongoing due to technological advancements. Utilizing the sun’s copious energy, solar panels constitute, in summary, an innovative technological advancement. They provide an encouraging pathway towards a more sustainable and renewable future by converting solar energy into a usable form of energy.

Functionality of Photovoltaic Cells

Photovoltaic cells, which are fundamental components of solar panels, are of utmost importance in the process of transforming solar energy into electrical energy. The operation of these cells is governed by the photovoltaic effect, a phenomenon identified by the French physicist Edmund Becquerel in 1839. Photovoltaic cells, which are predominantly composed of the semi-conductive material silicon, are engineered to absorb sunlight. Each cell is composed of two slender layers:
  • the p-type layer, which has a reduced number of electrons
  • the n-type layer, which is laden with additional electrons
Electrons are energized by the interaction of sunlight, which is composed of tiny energy units known as photons, with the surface of a photovoltaic cell. This increase in energy allows the electrons to get over the barrier between the two layers, which results in the generation of an electrical current. solar panel in section

Source: American Chemical Society

Photovoltaic cells produce an electrical current that is classified as direct current (DC). The majority of households and enterprises, nevertheless, are powered by alternating current (AC). As a result, DC electricity is converted to practical AC electricity via an inverter. The functionality of photovoltaic cells is heavily reliant on their efficiency. The peak efficiency documented thus far for a photovoltaic cell was 47.1%, which was attained by scientists affiliated with the National Renewable Energy Laboratory (NREL). Photovoltaic cells serve functions beyond the mere production of electrical energy. They contribute significantly to the worldwide effort to develop pure, renewable energy sources. Composed of these cells, solar panels offer an environmentally friendly substitute for fossil fuels by mitigating the release of greenhouse gases and diminishing our dependence on finite resources. By leveraging the principles of the photovoltaic effect and employing semi-conductive materials, these cells have emerged as a fundamental component of renewable energy technology.

Process of Conversion of Solar Energy to Electrical

Solar panels play a crucial role in converting the sunlight into electrical energy that can be utilized. They are alternatively referred to as photovoltaic cells. By integrating science, technology, and nature, this transformation is an extraordinary occurrence. The main stages of converting solar energy into electricity are given below: solar panels

Source: Live Science

Absorption of Light

Solar panels absorb sunlight in the initial phase of the conversion procedure. Multiple photovoltaic cells, comprising semiconductor materials like silicon, constitute the solar panel. The cells undergo a transfer of energy from the assimilated light to the semiconductor when exposed to sunlight, which consists of photons, which are particles of light.

Generation of Electron-Hole Pairs

The electrons are excited by the transferred energy, which causes them to move and produce gaps or ‘holes.’ This exchange of electrons and holes produces an electron-hole pair. Because they transport the necessary electric charge for the conversion process, the formation of these pairs is vital.

Separation of Charge Carriers

An electric field subsequently separates charge carriers within the solar cell. Because of the interface between distinct layers within the photovoltaic cell, an electric field is generated. The electric field shapes the solar cell so that holes are directed in the rear, and electrons are directed in the front.

Creation of Electric Current

A circuit is created externally by the movement of these charge carriers. By moving electrons from the front contact to the rear when the circuit is closed, an electric current can be generated. Absorption of light, production of electron-hole pairs, separation of charge carriers, and generation of an electric current are all components of the intriguing process by which solar energy is converted to electrical energy. The significance of comprehending and enhancing this conversion process escalates in tandem with our ongoing pursuit of sustainable energy sources.

Technological Developments of Solar Panels

Solar technology has undergone an extraordinary evolution, and it continues to reduce costs and increase efficiency. An exploration of the technological advancements that have improved the process of converting solar energy into electrical energy is warranted.
  • Developments in the field of photovoltaic technology: the PV cell is the central component of every solar panel; it transforms sunlight into electrical energy. Produced from crystalline silicon, the first generation of PV cells could convert approximately 15% of sunlight into electricity. The National Renewable Contemporary third-generation PV cells, constructed from thin-film materials, have the capability to convert as much as 22% of the sun’s energy due to technological advancements.
  • Perovskite solar cells: the introduction of perovskite solar cells represents a highly auspicious development in the field of solar technology. These cells, which are composed of a hybrid organic-inorganic lead or tin halide compound, have demonstrated efficiency rates of a potential 25.5%.
  • Solar tracking systems: solar surveillance systems have been devised with the intention of optimizing the conversion of solar energy. By enabling solar panels to track the sun’s trajectory across the sky, these systems can augment their solar exposure by as much as 45% in comparison to stationary panels.
  • Concentrated solar power (CSP): this technology generates electricity by concentrating sunlight onto a limited area, typically a PV cell, using mirrors.
  • Solar storage technology: an inherent drawback of solar power is its sporadic availability, which restricts its usage to periods when the sun is visible. Nevertheless, progress in battery storage technology has enabled the storage of surplus solar energy for periods of inclement weather, thus augmenting the overall efficiency of solar power systems.
Solar panels and associated system technological advancements have substantially increased the efficiency with which sunlight is converted to electricity. Anticipated advancements in research will further refine solar power, rendering it an even more feasible and environmentally sustainable energy source.

Systems of Distribution and Storage of Solar Energy

After being harnessed and converted by solar cells, solar energy must be stored and distributed efficiently in order to be utilized effectively. This is accomplished by integrating distribution and storage systems in a unified effort to guarantee energy efficiency and dependability.

Systems of Distribution

The responsibility of transporting the converted electrical energy to the designated location for utilization lies with these systems. Two distinct categories can be applied to them:
  • Direct systems: utilize the converted solar energy immediately. For instance, when installed on a rooftop, solar panels can provide direct power to the residence’s lighting and appliances. In 2022, residential solar panels accounted for 18% of all solar energy produced in the US, or 37 million megawatt-hours.
  • Indirect systems: utilize power grids to distribute the electricity generated by solar panels to numerous locations. Plants commonly employ indirect distribution systems.
 scheme of operation of solar panels with direct and indirect system

Source: inverter.com

Storage System

Alas, solar energy does not consistently prove to be accessible at the required moment. The sun is nocturnal and may be partially obscured by clouds during the day. In order to surmount this obstacle, storage systems are implemented:
  • Battery-powered storage systems: these apparatuses are designed to retain surplus solar energy generated during the day in order to utilize it at night or in periods of minimal sunlight. In the second quarter of 2023, 1,510MW of large-scale battery energy storage system (BESS) deployments occurred.
  • Thermal storage systems: these are alternative methods of energy storage in which surplus solar radiation is utilized to warm water that can subsequently be converted into electrical energy.
scheme of operation of solar panels using a storage system

Source: Unbound Solar

The critical function of solar energy storage and distribution systems is to ensure that the converted electrical energy is utilized efficiently. With the continuous advancement of technology that refines these systems, solar energy is poised to emerge as a progressively substantial component of our energy portfolio.

Connecting a Grid-Tied Solar System to Your Home

A series of procedures are required to convert solar energy into functional electrical energy when connecting a residential solar system to the utility. Homeowners can advantageously utilize solar energy in a dependable and economical fashion with the proper guidance; this procedure is not as complicated as it may seem. The process of installing a solar system in a residential home consists of the following steps:
  • Evaluation: conduct a comprehensive assessment of the energy requirements of your residence. The factors to be considered in this analysis comprise the orientation and pitch of your roof, your average monthly electricity usage, and the prevailing local weather conditions. Accurately determining the requisite solar system’s size and capacity requires this information.
  • Selection of a solar system: choose the solar system that most effectively fulfills your requirements, per the assessment. Capabilities of solar systems are quantified in kilowatts (kW), with the average residential system functioning within the range of 3 to 10 kW.
  • Installation: mounting the solar panels to the roof and connecting them to an inverter constitute the installation phase. Important to the solar system, the inverter transforms the direct current (DC) generated by the panels into the alternating current (AC) utilized in residential appliances.
  • Distribution to the grid: following the installation process, the system must be linked to the residential grid. It is necessary to install a bi-directional meter and connect the system to the main electrical panel of your residence. This meter displays the amount of electricity generated by your system as well as any surplus that it returns to the power grid.
  • Inspection and activation: a local authority or utility company will conduct an inspection and activation of the system to verify that it satisfies performance and safety requirements. The system will commence supplying solar energy to your residence once it has been approved and activated.
Depending on location and weather conditions, a 5 kW solar system, which consists of 15-20 solar panels, is suitable for most residences. Energy costs can be substantially reduced, and reliance on utility electricity can be minimized by attaching a residential solar system to the grid.

In Conclusion

Solar panels, in summary, are indispensable for the conversion of light energy into electrical energy that can be utilized. From the absorption of sunlight by solar panels to the production of an electric current, this process is intricately detailed in the article. With an emphasis on the significance of the photovoltaic effect, the structure and operation of solar cells during the conversion process are described. Solar tracking systems and third-generation PV cells, which have substantially increased the efficiency of solar energy conversion, are among the technological advancements discussed in greater detail in the article. An examination is also conducted into the crucial significance of storage and distribution systems in guaranteeing the efficient utilization of converted solar energy. An instructional manual describing the process of connecting a residential solar system to the power grid is the final section of the article. Recognizing and improving solar energy conversion becomes ever more crucial as the global community continues to explore sustainable energy alternatives.

Jed Hilton
Jed Hilton

Jed Hilton, our Founder and CEO, has over a decade of experience in the solar industry. His innovative leadership and expertise in solar technologies guide our company's vision and strategy.

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