How Do Solar Panels Work? Key Applications and Benefits
We use solar panels to generate electricity. This process can take place either for domestic or industrial purposes. Domestic solar panels can be used in generating electricity at home.
And in the industrial panel, we use it to generate electricity in mass. For this, engineers need to install an array of solar panels from a solar power station. Solar panels can be used to generate large amounts of electricity, and this process can take place both at solar and industrial scales. A key benefit of solar panels is that they can be used in providing electricity in remote areas as well, provided there is enough solar energy at that place. This will help the people living there.
What are Solar Panels?
Solar energy is the energy that the Sun gives to the Earth, primarily as visible light and then later in electromagnetic radiation. Solar energy was developed nearly 100 years ago. Earlier solar energy was used in generating streams, which was then used to drive machinery.
Edmond Becquerel discovered the photovoltaic effect, which allowed the conservation of sunlight solar electric energy. Sun’s energy is captured by the solar panel and they convert that light into electricity, which is then used to provide the power of electrical loads.
Such panels contain several individual solar cells which are composed of many layers of silicon, phosphorus, and boron. Solar panels absorb the photons and electric current is produced in doing so.
The energy which is the result of this strikes the surface of solar panels allows electrons to be knocked out of their atomic orbits and released into the electric field generated by the solar cell. This pulls the free electrons in the directional current. This whole process is known as the photoelectric effect.
For the necessary number of solar panels, an average home has more than enough roof area to produce enough solar electricity to supply the power needs.
Materials Used in Solar Panels
A solar cell is the most important component of any solar panel. A single solar panel, for example, is made up of a number of solar cells. These cells are a component of the technology that converts sunlight to energy. The majority of solar panels use crystalline silicon solar cells. These cells are made up of silicon, phosphorous, and boron layers (although there are several different types of photovoltaic cells). Once created, these cells are arranged out in a grid arrangement. Because there are so many various-sized possibilities, the number of these cells needed is generally determined by the size of the panel being built.
After the cells are set out, the panel is sealed and coated with a non-reflective glass to safeguard the cells within. This non-reflective glass protects the solar cells from harm while yet allowing sunlight to reach them. This panel is then sealed and inserted into a sturdy metallic frame. This frame is made to avoid deformation and contains a drainage hole to prevent water from accumulating on the panel, which might impair the panel's effectiveness. In order to avoid damage, the rear of the panel is likewise sealed.
Working of Solar Panels
Solar panels are used to mount a number of solar cells in order to harness their unique features to create power. The photovoltaic effect occurs when individual cells absorb photons from the Sun, resulting in the generation of an electric current in the cell. A solar panel generates direct current, which is converted to alternating current via an inverter. When these two technologies are combined, they form a photovoltaic system. When installing a solar panel, the optimum orientation is selected so that the solar panel faces the most appropriate direction for the application. This is usually done to generate the greatest yearly energy, although it isn't always the case.
Construction of Solar Panel or Solar PV
Photovoltaic modules employ the photovoltaic effect to create electricity from light energy (photons) from the Sun. Wafer-based crystalline silicon cells or thin-film cells are used in the majority of modules. The top layer or the rear layer of a module might be the structural (load-bearing) element. Mechanical and moisture damage to cells must be avoided. The majority of modules are stiff, while thin-film cell-based semi-flexible modules are also available. Electrically, the cells are normally linked in series to get the necessary voltage, then in parallel to boost current. The mathematical product of the module's voltage (in volts) and current (in amperes) gives the module's power (in watts).
The production parameters for solar panels are derived under normal conditions, which are not representative of the real-world operating conditions that the solar panels face on the installation site.
The solar panel's output interface is a PV junction box, which is mounted to the rear of the panel. Most photovoltaic modules include MC4 connectors on the outside to allow for easy weatherproof connections to the rest of the system. It's also possible to use a USB power interface.
Energy and Uses
Radiant light and heat from the Sun are known as solar energy.
To heat water, solar hot water systems use sunlight. In the middle geographical latitudes that are 40 degrees North and 40 degrees South, by the solar heating system, 60 70% domestic hot water use can be provided, with the water temperature at 60 degrees celsius.
Evacuated heat collectors are the most common type of solar water heater, and glazed flat plate collectors are also considered good solar water heaters.
The total installed capacity of the solar hot water system was approx 154 thermal gigawatts as of 2007. China is the leader as in 2006 it had a deployment of 70 gigawatts and 210 gigawatts in 2020. Israel and Cyprus are also per capita leaders in the usage of solar hot water systems.
Solar energy is not only used in heating water but also in many other things in the house for cooking purposes, process heating, water treatments, electricity production, heating, cooling, ventilation, etc.
Usage of Solar Panels in Agriculture
As we are aware of many uses of solar energy in different fields, one of those fields includes agricultural activities also. Solar energy is the supplement of many farm energies. Solar energy is very helpful in agricultural activities as well. Solar energy is used in crop and grain drying and it’s one of the oldest and most widely used techniques in agricultural activities.
The basic components of a solar dryer are screened drying trays or racks and solar collector, enclosure, or shed. Solar energy is also used in space and water heating. Air and water heating requirements are often more in the dairy operations, modern poultry farms raise animals in enclosed buildings where it's very important to control temperature and air quality.
The next application is greenhouse heating. The greenhouse depends on the Sun for their needs, they rely on oil and gas heaters to maintain the temperature for the plants to grow in winters.
Uses of Solar Panels for Electricity
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For the renewable energy available, the Sun is the purest source. It can be used in many forms to help power our house and business. Solar-powered photovoltaic panels convert the rays of the sun into electricity. In this process, electrons get excited in the silicon cell using the photons from sunlight. This electricity provides renewable energy.
The solar panels are placed at the top of the houses in most solar systems. There will be no shade on the panel side of an ideal site especially from 9 Am to 3 Pm. South facing installation provides the optimal potential for the system. While placing the solar panels we should take care of a few of the factors like trees should not be there near the house so that sunlight is not blocked and full productive use of solar panels is done.
In the solar panels even if one out of the 36 panels is covered, then it will be very less productive. These are the few factors that are to be taken care of while placing a solar panel set.
Conclusion
Solar energy is the energy that the Sun gives to the Earth in visible and electromagnetic forms. We use solar panels to convert that light into electricity, which is then used to provide the power of electrical loads. The process can take place both at a solar and industrial scale.
FAQs on Uses of Solar Panels in Everyday Life and Physics
1. What is the main purpose of a solar panel?
The primary purpose of a solar panel is to absorb sunlight and convert it directly into electrical energy. This process is called the photovoltaic effect. The direct current (DC) electricity generated can then be used to power devices, charge batteries, or be converted to alternating current (AC) for household and industrial use.
2. What are some common examples of how solar panels are used?
Solar panels have a wide range of applications, from small-scale to large-scale projects. Common examples include:
- Residential Power: Providing electricity to homes to reduce reliance on the main power grid.
- Water Pumping: Powering water pumps for irrigation in agriculture, especially in remote areas.
- Street Lighting: Operating off-grid streetlights in cities, highways, and rural communities.
- Telecommunications: Supplying power to remote satellites and communication towers where grid access is difficult.
- Portable Power: Charging devices like phones, cameras, and laptops using small, portable solar chargers.
- Industrial Power Plants: Large solar farms, or solar parks, that generate vast amounts of electricity for the community grid.
3. How does a solar panel convert sunlight into electricity?
A solar panel converts sunlight into electricity through the photovoltaic effect. Each panel consists of multiple solar cells made from semiconductor materials like silicon. When sunlight, which is made of particles called photons, strikes a solar cell, it transfers energy to electrons in the silicon, knocking them loose. An internal electric field within the cell then directs these free electrons into a continuous flow, creating a direct current (DC).
4. What is the key difference between a solar panel (PV) and a solar water heater (thermal)?
The key difference lies in the type of solar energy they are designed to use and their final output.
- A solar panel (Photovoltaic or PV) uses the light energy (photons) from the sun to generate electricity.
- A solar water heater (Thermal) uses the heat energy (infrared radiation) from the sun to directly heat water or another fluid that circulates through its collectors.
5. Why don't standard grid-connected solar panels work during a blackout?
This is a critical safety feature known as "anti-islanding". During a power outage, utility workers must repair the grid lines. If home solar systems continued to feed electricity back into the grid, they would create dangerous “islands” of live power that could fatally electrocute the workers. To prevent this, grid-tied inverters are designed to automatically shut down when they detect a loss of power from the utility grid.
6. How are solar panels specifically used in a country like India?
In India, solar panels are used extensively to meet diverse energy needs, in line with national goals for renewable energy. Key applications include:
- Large-scale solar parks and farms in states like Rajasthan and Gujarat that contribute significantly to the national grid.
- Rooftop solar installations on homes, schools, and commercial buildings, often promoted by government subsidy schemes.
- Powering agricultural solar water pumps to help farmers in areas with unreliable electricity supply.
- Providing electricity to remote villages and hamlets that are not yet connected to the main power grid.
7. If a single solar cell in a panel gets shaded, why does it significantly reduce the entire panel's output?
Solar cells within a panel are typically connected in series, much like links in a chain. Electricity must flow through every single cell to complete the circuit. When one cell is shaded, it stops producing energy and acts like a point of high resistance, or a blockage. This "bottleneck effect" impedes the flow of current through the entire series of cells, drastically reducing the power output of the whole panel, not just the performance of the shaded area.
8. What are the main environmental benefits of adopting solar panel technology?
The primary environmental benefit of using solar panels is that they produce clean, renewable energy from the sun. This leads to several positive environmental impacts:
- It significantly reduces the emission of greenhouse gases like carbon dioxide, which are a major cause of climate change.
- It helps decrease air pollutants such as sulphur dioxide and particulate matter, leading to better air quality and public health.
- It reduces the global dependence on finite fossil fuels like coal, oil, and natural gas.
- It requires very little water to operate, which conserves water resources compared to traditional thermal power plants.
9. Do solar panels only work on hot, sunny days, or can they generate electricity in cloudy weather?
This is a common misconception. Solar panels generate electricity from light, not heat. Therefore, they can still produce power on cool or cloudy days. While their output is highest in direct, bright sunlight, they continue to generate a considerable amount of electricity from the diffuse ambient light that penetrates through clouds. In fact, extreme heat can slightly decrease a panel's efficiency and power output.
10. What kind of maintenance is required to keep solar panels working efficiently?
Solar panels are very durable and require minimal maintenance. To ensure they work at peak efficiency, the main task is to keep their surface clean and clear. Key activities include:
- Regular Cleaning: Washing the panels periodically to remove accumulated dust, dirt, pollen, or bird droppings that can block sunlight and reduce output.
- Obstruction Removal: Ensuring that nearby tree branches are trimmed so they do not cast shadows on the panels, especially during peak sunlight hours.
- Visual Inspection: Occasionally checking for any visible damage to the glass, frame, or wiring.
