he demand for solar panels has skyrocketed in recent years, making solar power a major player in the global energy market. The world's solar capacity reached 1 TW within a decade, from 100 GW in 2012, and the EIA anticipates that it will nearly triple from 2022 to 2027, surpassing coal and becoming the world's largest power source.
This article will delve into the basics of solar panels and their installation process. Starting from the components of solar cells to the panel installation process, we will provide a comprehensive guide to this increasingly popular energy option. So, whether you are planning to install a solar panel system or simply curious about this fascinating technology, keep reading to discover the fundamentals of solar panels.
The power of solar: an overview of solar energy and its benefits
The sun is an extraordinary source of power that emits more energy in a single second than the world consumes in a whole year. Luckily, we've discovered a way to harness this power through the use of solar panels, which capture the sun's energy and convert it into electricity using photovoltaic (PV) cells. Solar panels are gaining popularity due to their clean, renewable nature and the many benefits it offers.
One of the biggest benefits of solar panels is their environmental impact, or lack thereof. While solar panels do have a carbon footprint, the emissions generated over the lifecycle of solar electricity are approximately 12 times less than natural gas and 20 times less than coal. As a result, solar panels do not contribute to climate change, making them a more sustainable and responsible choice for our energy needs.
Besides being a sustainable energy source, solar panels reduce our dependence on non-renewable sources such as oil, coal, and gas. It can power homes, businesses, and even entire cities, saving energy bills and money in the long run. Solar panels are also becoming more affordable and easy to install and maintain, making them an excellent option for anyone looking to invest in renewable energy.
As the industry continues to grow and expand, the use of solar panels and other solar technologies creates jobs in manufacturing, installation, and maintenance. As a result, solar energy is beneficial not only for the environment but also for the economy.
How solar panels work
PV effect – solar power's fundamental principle
The photovoltaic effect, also known as the PV effect, is the bedrock of solar power. Essentially, it describes the ability of certain materials to produce an electric current when exposed to light.
This effect was first observed in 1839 by French physicist Alexandre-Edmond Becquerel, who noticed that certain materials generated electricity when they came in contact with light. But it wasn't until the 1950s that practical photovoltaic cells were created, initiating the modern solar industry. Since then, technology has advanced rapidly, with solar panels becoming more efficient and cost-effective.
Conversion of solar energy into electrical energy
Small interconnected units called solar cells are the basic components of a solar panel. These cells, constructed from materials such as silicon, operate by capturing the sun's energy and converting it into electricity.
Solar cells commonly use two layers of silicon, one positively charged (P-type) and one negatively charged (N-type), which are created by adding small amounts of other elements to the silicon. The top layer of the cell is infused with phosphorus atoms to form the N-type layer with a surplus of electrons, while the bottom layer is infused with boron to create the P-type layer with a shortage of electrons. When these two layers are placed side by side in a cell, they create an electric field similar to a battery. This unique setup allows for a reaction that produces electricity when the cells are exposed to sunlight.
When sunlight reaches a solar panel and hits a silicon cell, it knocks loose some electrons in its atoms. These energized electrons can then move around freely, and the electric field pushes them from one cell layer to another, thus generating electricity.
Shell Solar was a division of Shell focused on renewable energy solutions like solar power. They aimed to promote sustainability and reduce carbon emissions.
Types of solar panels
Crystalline solar panels: Monocrystalline vs. Polycrystalline vs. PERC
Silicon crystal-based PV panels, known as crystalline silicon solar panels, are the most commonly used panel type in residential and commercial applications, accounting for 95% of the market. They can be classified into three main types, namely monocrystalline panels, polycrystalline panels, and PERC (Passivated Emitter and Rear Contact) panels.
Monocrystalline silicon panels use cells created from a solitary silicon crystal and have a higher efficiency rate compared to polycrystalline panels due to their more consistent structure, which enables electrons to flow more easily through the panel, resulting in increased energy output. Despite their higher efficiency and ability to generate more electricity in a smaller area, monocrystalline panels are more expensive than polycrystalline panels.
Polycrystalline silicon solar panels contain cells created from several silicon crystals and have a lower efficiency rate than monocrystalline panels because their structure is not uniform, making it more difficult for electrons to move. Nevertheless, they are an economical choice and are frequently used for residential PV panel installations.
PERC solar panels are an upgraded variation of monocrystalline panels, utilizing PV cells with a unique layer on the back to enhance their efficiency. This layer helps reflect light back into the cell, reduces electron recombination, and allows for greater reflection of light waves over 1,180nm. As a result, PERC silicon panels can collect more solar energy in a smaller area and are an excellent choice for limited spaces.
Thin-film solar panels
Thin-film panels differ from traditional silicon panels in that they are composed of layers of PV material deposited onto a substrate, such as glass, plastic, or metal. This results in a lighter and more flexible panel, which can be applied to a broader range of surfaces, including curved ones. Additionally, manufacturing costs for thin-film panels are lower than those for conventional panels, as they require less silicon and other expensive materials. Nevertheless, they are typically less efficient than crystalline silicon panels and may degrade faster over time.
Solar panel components
Silicon solar panels consist of multiple elements that collaborate to create energy from sunlight. Solar cells are the foundation, but there are other vital components.
A metal frame maintains the panel stability during rough weather. It's made of durable, light materials such as aluminum. A tempered glass or plastic cover shields the panel and its cells from the elements while helping to trap the sun's energy. To protect the silicon cells from potential damage caused by moisture and other external factors, panels are coated with a thin layer of polymer material known as the backsheet.
Factors affecting solar panel efficiency
Over the last ten years, there has been a noteworthy improvement in the efficiency of silicon solar panels. As per the National Renewable Energy Laboratory (NREL), back in 2002, the average panel efficiency rate was merely 13.6%. Today, the majority of silicon solar panels have an efficiency range of 15-20%, with a select few boasting around 23%. However, the figures listed in the spec sheets indicate the utmost efficiency, but it's crucial to consider how various real-world factors affect solar panel performance.
Solar panel design and materials
The design and materials used to make a solar panel can significantly impact its efficiency. For example, panels featuring high-quality, monocrystalline silicon cells are known to be more efficient than those with cheaper polycrystalline cells.
Solar panel temperature
It turns out that solar panels work best when they're cool, and as temperatures rise, their performance decreases. The electrons in solar cells tend to move slower when it's hot outside, limiting the amount of energy a panel can produce.
Anything that blocks sunlight from reaching the panels will inevitably reduce their energy output. This can be anything from a neighboring building to the leafy branches of a nearby tree. When installing solar panels, it's essential to choose an unobstructed location to maximize their efficiency.
Solar panel angling
If the panel is angled too steeply or shallowly, it may not receive enough sunlight to generate optimal energy. Ideally, solar panels should be angled at the latitude of the location where they are installed. For example, if you live in a place with a latitude of 40 degrees, your solar panels should be angled at 40 degrees for maximum efficiency.
Solar panel orientation
In addition to the angle of the solar panel, its orientation is also essential. Solar panels should ideally be installed facing south in the Northern Hemisphere and north in the Southern Hemisphere. This helps ensure that the panel is exposed to the maximum amount of sunlight throughout the day.
Dust and debris on solar panels
It is important to keep solar panels clean and free of dust and debris. Over time, dirt and grime can accumulate on the panels, reducing efficiency. Regular cleaning is, therefore, essential to maintain optimal panel performance.
Solar panel installation process
Installing solar panels requires several steps, including a comprehensive site assessment, system design, and panel installation. Let's take a closer look at each step of the process.
Solar site assessment
The first step in the PV panel installation process is to evaluate the site's suitability for solar panels. During this assessment, a thorough inspection of the location is carried out to check the orientation and tilt of the roof, the amount of shade present, and the available space for solar panels.
Designing the solar panel system
The next stage is to plan a solar panel system that suits the property. This includes picking the right type of solar panels, calculating the number of panels required to fulfill the household’s energy requirements, and designing the wiring and mounting systems. A thorough strategy is then devised, outlining the panel layout, the inverter's placement, and the grid connection.
Installing the solar panels
When the site analysis and system design have been completed, the solar panels are put in place. The process involves securing the panels to the roof or ground, connecting them to the inverter, and then linking the inverter to the electrical grid. Once the panel setup is completed, a comprehensive testing process is carried out to verify that the PV panel system is functioning correctly and generating the desired amount of energy.
Solar Panel FAQs
How long do solar panels last?
Most residential solar panels are capable of functioning well for up to 25 years before any noticeable decline in energy output occurs. Even after this time, the panels can still convert sunlight into solar energy, although at a lower efficiency than their peak performance. The durability of solar panels depends on various factors, such as the quality of materials, the panel installation process, and the level of maintenance.
How much energy can solar panels produce?
The power output of solar panels that are available today is usually between 250 and 400 Watts. Nevertheless, the actual output of a panel may vary depending on specific factors, such as shading, the position of the panels, and the amount of sunlight.
How much do solar panels cost?
The average solar panel cost ranges from $3 to $5 per watt, which means that a typical 6 kW solar panel system can cost anywhere between $18,000 and $30,000. The cost can be impacted by several variables, such as the size of the system, the type of PV panels, and the solar incentives available.
Summary of solar panel technology and benefits solar power offers
To sum up, solar power is a fast-growing industry that offers sustainable and renewable energy. It is expected to triple by 2027 and become the world's largest power source. Solar panels have numerous benefits, including lower energy bills and a smaller carbon footprint.
To invest in solar energy, it's important to understand the fundamentals of solar panels, including panel types, efficiency factors, and installation processes. With the decreasing cost and increased accessibility of solar panels, now is the best time to transition to this eco-friendly and renewable energy source.