Amidst the mounting challenges of climate change, the pursuit of sustainable solutions has gained real momentum. In this context, renewable energy has emerged as a leading contender, offering promising prospects to combat pressing environmental concerns. One key example of renewable energy technology is solar panels, which have become increasingly popular due to their ability to harness abundant and zero-carbon electricity and their good scalability to suit different localities and applications. By converting sunlight into electricity, solar panels have the potential to wean the global energy sector off fossil fuels and help transition the world to a low-carbon future. This article will take a deep dive into solar panel technology, answering the questions: What is a solar panel, how do solar panels work and what are their various applications?
The solar technology that will be focused on in this article is solar PV (photovoltaic), which directly converts sunlight into electricity through the photovoltaic effect. Solar CSP (Concentrated Solar Power) systems, on the other hand, use mirrors or lenses to concentrate sunlight onto a receiver, which is converted into thermal energy, which then can be used for electricity generation. Solar PV is more popular than solar CSP given the technology’s cost-effectiveness, scalability, geographic suitability, simple installation, and maintenance, as well as its widespread use in residential and distributed applications. However, to find out more about CSP technology, click here.
Solar PV Panels Q&A With An Expert
What is a solar panel?
Solar photovoltaic (PV) panels, also known as modules, are devices that convert sunlight into electricity using a technology called the photovoltaic effect. They are a key component of solar energy systems and play a crucial role in harnessing renewable energy from the sun.
What are solar panels made from?
Solar cells are the building blocks of solar panels. They are typically made from semiconductor materials, most commonly silicon. Silicon solar cells are either monocrystalline or polycrystalline, depending on their crystal structure. They are placed in a protective and transparent layer, such as tempered glass, to shield them from the environment and enhance light absorption.
How do solar panels work?
When sunlight, which consists of tiny particles of energy called photons, reaches the surface of the solar panel, it interacts with the semiconductor material. This interaction energizes electrons within the material, causing them to break free from their atomic bonds.
As electrons, each carrying a negative charge, move toward the front surface of the solar cell, an electrical imbalance arises between the cell’s front and back surfaces. This imbalance generates a voltage potential, similar to a battery’s positive and negative terminals. The electrical conductors on the cell absorb these electrons. When the conductors are connected to an external load, like a battery, electric current flows through the circuit. This flow of electric current constitutes what is known as direct current (DC), as the electrons move in a continuous, unidirectional manner.
However, the generated DC from a solar cell might not be immediately suitable for powering most household and industrial appliances, which typically run on alternating current (AC). To make this DC power usable, an inverter is employed. The inverter converts the steady DC from the solar cell into the alternating current required by the electrical grid and the devices connected to it.
What is a solar panel? The image above shows what the inside of a solar panel looks like.
The individual photovoltaic cells are then connected in series or parallel to form a solar panel. A collection of multiple solar panels can be combined to create a solar array or solar system.
Types of Solar Panels
There are three main technology types of solar panels, each offering distinct advantages and applications. We will look at the individual technologies more closely now:
1. Monocrystalline Solar Panels: Monocrystalline solar panels are made from single-crystal silicon, resulting in a highly efficient and uniform structure. The manufacturing process involves cutting cylindrical silicon ingots into thin wafers, which are then used as the basis for individual solar cells. The high purity of monocrystalline silicon makes these panels more efficient at converting sunlight into electricity compared to other types.
The distinguishing feature of monocrystalline solar panels is their dark black color and rounded edges. Their high efficiency means they require less space for the same power output, making them ideal for installations with limited roof or ground space. However, their higher manufacturing costs can lead to slightly elevated prices.
2. Polycrystalline Solar Panels: Polycrystalline solar panels are made from multiple crystal structures of silicon, resulting in a blueish appearance. The manufacturing process involves melting raw silicon and pouring it into molds to create square-shaped wafers. Polycrystalline panels are easier and cheaper to produce than monocrystalline panels, which makes them a cost-effective option.
While slightly less efficient than monocrystalline panels, advancements in technology have reduced the efficiency gap between the two types. Polycrystalline panels offer good performance and cost-effectiveness, making them popular for residential and commercial installations.
3. Thin-Film Solar Panels: Thin-film solar panels are made using thin layers of semiconductor material, such as amorphous silicon, cadmium telluride, or copper indium gallium selenide (CIGS). The thin-film technology allows for flexible, lightweight, and versatile solar panels that can be integrated into various surfaces, including curved or irregular shapes.
Thin-film panels are less efficient than monocrystalline and polycrystalline panels but have advantages in certain applications. They perform better in low-light conditions and are less sensitive to high temperatures. Their ease of integration makes them suitable for building-integrated photovoltaics (BIPV), solar shingles, and other innovative solar designs.
Efficiency & Performance
Several factors impact the efficiency of solar panels, determining how effectively they convert sunlight into electricity. Understanding these factors is crucial in selecting the most suitable solar panels for specific applications and maximizing energy production.
Type of Solar Cell: Different types of solar cells, such as monocrystalline, polycrystalline, and thin-film, have varying efficiency levels. Monocrystalline cells generally offer higher efficiency due to their single-crystal structure, as highlighted above.
Temperature: Solar panel efficiency decreases as temperatures increase. Higher temperatures reduce the voltage output of the solar cells, impacting overall energy production.
Shading and Obstructions: Shading on even a small portion of a solar panel can significantly reduce its output. Obstructions like nearby buildings or trees can also cast shadows, leading to efficiency losses.
Tilt and Orientation: The tilt and orientation of solar panels affect how they capture sunlight. Panels should ideally be positioned to face the sun directly for optimal energy production.
Soiling and Dirt: Dust, dirt, or debris on the surface of solar panels can obstruct sunlight and decrease efficiency. Regular cleaning and maintenance are essential to ensure maximum performance.
Age and Wear: Over time, solar panels may experience slight performance degradation due to exposure to environmental factors, including UV radiation and weather conditions.
The lifespan of solar panels varies, but most reputable manufacturers offer warranties ranging from 25 to 30 years. Panels can continue to produce electricity well beyond their warranty period, albeit with reduced efficiency. Environmental conditions, maintenance, and the quality of materials used can influence a solar panel’s lifespan. Proper care and regular inspections can extend the life and performance of solar panels.
What Are The Applications Of Solar Panels?
As we have discovered in many of our previous articles, solar power is crucial to environmental sustainability and the mitigation of global climate change. The technology’s remarkable versatility and wide range of applications make it an excellent and sustainable solution to address our energy needs.
Solar PV is a highly versatile technology that offers modularity, allowing it to be produced in large-scale plants, benefiting from economies of scale. However, it is equally adaptable for deployment in small quantities, enabling a diverse range of applications. From small residential rooftop systems to expansive utility-scale power generation installations, solar PV caters to a wide spectrum of energy needs.
Residential solar systems are becoming increasingly popular as homeowners embrace clean energy and seek to reduce their reliance on conventional power sources. Solar panels installed on residential rooftops or ground-mounted on properties generate electricity to power household appliances, lighting, and other electrical devices. Excess electricity can be fed back into the grid, earning homeowners credits or financial compensation through net metering programs.
Commercial and industrial installations harness solar energy to power businesses, factories, offices, and other large-scale facilities. Solar panels are mounted on rooftops, parking structures, or open land adjacent to commercial premises, providing clean electricity to meet a significant portion of their energy needs.
Utility-scale projects refer to large-scale solar installations designed to generate a significant amount of electricity for the grid. These projects are typically developed by utility companies, independent power producers (IPPs), or energy developers, with the primary goal of supplying clean and renewable energy to meet the electricity demands of a region or community.
Off-grid and decentralized applications can be crucial in providing electricity to off-grid and remote areas where traditional power infrastructure is unavailable or impractical. Off-grid solar systems, often paired with battery storage, offer reliable electricity for remote homes, villages, telecommunications equipment, and water pumping stations.
The Future Of Solar
Innovations in solar technology will continue to drive the efficiency and performance of solar panels, propelling its expansion over the coming decade. Our research shows that the global solar energy market will grow at a CAGR of 7.2% between 2023 to 2030, with the market size totaling nearly USD350 billion by 2030.
Despite increases in investment costs due to rising commodity prices, utility-scale solar PV is the least costly option for new electricity generation in most countries worldwide. Distributed solar PV, such as rooftop solar on buildings, is also set for faster growth because of higher retail electricity prices and growing policy support.
The exceptional growth in PV deployment in recent years will need to continue and scale up to follow the Net Zero Emissions by 2050 Scenario, requiring continued policy ambition.
This article has effectively answered the question of what a solar panel is and provided an in-depth overview of how the technology works, its applications, and its future trajectory.
Ongoing advancements in solar technology and emerging trends in solar panel design hold great promise for transforming the energy landscape. With increased efficiency, innovative applications, and lowering costs, solar power is poised to play a central role in the transition to a cleaner global energy system.