How Solar Panels Work: A Brief Explanation

Solar panels convert sunlight into electricity through the photovoltaic effect. They absorb photons from the sun using advanced materials. The energy from the photons knocks electrons free from the atoms, creating an electric current. This current flows through the panel, captured by wires, and sent to an inverter. The inverter changes the electricity from DC to AC, which powers our homes and businesses. Extra electricity can be stored in batteries or sent back to the grid.

This short video by Which? Explains how solar panels work quickly and easily.

What Are Solar Panels Made Of? The Parts And Materials Explained

Solar panels consist of various essential parts that work together to generate clean, renewable energy.

1. Solar Cells:

The heart of a solar panel is comprised of tiny, light-absorbing devices called solar cells. Made predominantly of silicon, these cells convert sunlight into direct current (DC) electricity through the photovoltaic effect.

2. Solar Panel Frame:

The frame provides structural support and protection to the solar panel. Usually made of aluminum or steel, it ensures durability and helps inhibit moisture penetration. The frame also makes installation easier and facilitates the proper positioning of the panels for optimal sunlight exposure.

3. Solar Panel Backsheet:

Located behind the solar cells, the backsheet acts as a barrier against moisture and other environmental factors that may damage the interior components. Typically made of polymer, it provides electrical insulation and enhances the overall durability and lifespan of the solar panel.

4. Junction Box:

The junction box is an important component that houses the electrical connections of the solar panel. It prevents water ingress and acts as a safety feature, safeguarding against electric shock. Additionally, it enables easy access for system maintenance and troubleshooting.

5. Inverter:

The inverter is responsible for converting the DC electricity produced by the solar panel into alternating current (AC) electricity, which is the type used in most household appliances. This conversion allows for the seamless integration of solar power into the existing electrical grid or for immediate use within a standalone system.

In summary, solar panels comprise various essential parts, including solar cells, the frame, backsheet, junction box, and inverter, which all work together harmoniously to convert sunlight into usable electricity.

Solar PV Inverters: What Are They?

A solar inverter is an essential device in a solar power system that converts direct current (DC) electricity produced by solar panels into alternating current (AC) electricity. The primary purpose of the inverter is to enable the use of solar-generated electricity in homes or feed it back into the grid.

DC electricity is the type of electricity that is produced by the solar panels when they receive sunlight. However, most of the appliances and devices we use in our homes require AC electricity to function. This is where the solar inverter comes into play. It converts the DC electricity into AC electricity, making it usable for household purposes.

There are two main types of solar inverters: central inverters and micro-inverters. Central inverters are typically used in larger solar power systems, where multiple solar panels are connected in series. They are more cost-effective but can be affected by shading or performance issues.

On the other hand, micro-inverters are installed on each individual solar panel in smaller systems. They optimize the performance of each panel by converting DC to AC right at the panel level. This ensures that even if one panel is shaded or underperforming, it won’t affect the overall system’s efficiency.

In summary, a solar inverter plays a crucial role in converting the DC electricity produced by solar panels into AC electricity that can power our homes or be transmitted back into the grid. Different types of inverters, such as central inverters and micro-inverters, are used to optimize solar panel performance and ensure maximum efficiency.

Generation Meters For Solar

The generation meter is used to monitor the system’s generation. It serves the purpose of measuring the amount of electricity generated.

Its functionality involves displaying the energy produced by the system. This is important for keeping track of the system’s performance and efficiency.

To indicate the system’s generation, the meter has a flashing red light. On brighter days, the light flashes faster, providing a visual indication of increased energy production.

This makes it easier to assess the system’s performance at a glance.

The generation meter plays a crucial role in monitoring the system’s energy generation, allowing users to keep track of its efficiency and performance.

Export Limiters – Optional

Export limiters, if applicable, serve the purpose of capping or stopping the exportation of excess electricity back to the grid during periods of non-consumption. Their function is to prevent the flow of surplus power from the consumer’s energy system to the grid when it is not needed.

These devices are designed to ensure that electricity generated from solar panels is used locally rather than being exported to the grid. By limiting or stopping exportation, these devices help to optimize the self-consumption of renewable energy within the consumer’s premises – like stroing the energy in a solar battery instead.

The main goal of export limiters is to reduce reliance on the grid and maximize the use of your own generated renewable energy, improving your energy independence. They are particularly useful in situations where consumers generate more electricity than they consume, allowing them to use the excess power instead of exporting it to the grid.

Although you can get paid for your excess energy through the Government-backed Smart Export Guarantee (SEG) scheme, using your own stored electricity is chepaer than exporting electricity and buying it back when required.

Solar PV Export Meter

A solar export meter is a device that measures the amount of electricity generated by a solar PV (photovoltaic) system that is sent back to the grid. In the UK, when you have a solar panel installed, any excess electricity that you don’t use is exported to the National Grid.

The solar export meter calculates how much electricity is being exported and records this information. It helps you keep track of how much electricity you are exporting and allows you to be paid a tariff, called the Feed-in Tariff (FiT (discontinued in 2019)) or the Smart Export Guarantee (SEG), for the electricity you export. These tariffs vary depending on the energy supplier.

The export meter subtracts the amount of electricity that you use from the total generated, giving you the amount that is being exported.

PV Cabling And Connectors

In the UK, solar panel installations typically use cables and wires that are designed specifically for this purpose. These cables are known as solar cables or PV (photovoltaic) cables.

Solar cables are specially made to withstand the conditions encountered in solar panel systems, such as high temperatures, UV rays, and outdoor environments. They have a durable outer sheath that protects the internal conductors, ensuring the safety and performance of the system.

These cables are typically made of materials that are resistant to sunlight, moisture, and heat, such as cross-linked polyethylene (XLPE) or ethylene propylene rubber (EPR). They are available in different sizes, commonly ranging from 1.5 mm² to 10 mm².

Connectors are also an important part of solar panel installations, as they allow the connection between the solar panels, inverters, and other components. MC4 (Multi-Contact 4) connectors are commonly used in the UK for solar installations. These connectors are weatherproof and provide a reliable and secure connection.

Solar Battery Storage

Solar battery storage is an optional add-on system that stores excess energy generated by solar panels. It’s like having a backup energy source that you can use when your solar panels are not generating enough electricity, such as during the night or on cloudy days.

One of the main benefits of solar battery storage is that it allows you to use the energy you generate during the day, even when the sun is not shining. This means you can avoid relying on the grid and reduce your energy bills.

The cost of solar battery storage can vary, but generally ranges from around £1,500 to £8,000. There are a variety of battery sizes, typically starting at 2 KW up to 10+ KW. This includes the cost of the battery itself, as well as installation and any additional equipment that may be needed.

Investing in solar battery storage provides long-term savings by maximizing the use of your solar energy and reducing your reliance on the grid. Additionally, it can provide peace of mind during power outages, as you will still have access to electricity stored in the battery.

By storing excess solar energy and using it as a backup when needed, solar battery storage offers an efficient and sustainable solution for managing your electricity needs.

Solar PV Mounting System, Rails And Fixings

Solar panels are typically fixed and mounted using a solar PV mounting system, which consists of rails and fixings. The mounting system serves the purpose of securely fastening the solar panels to the roof or ground, ensuring their stability and optimal performance.

Rails are the main component of the mounting system, and they are typically made from aluminum or steel. These rails are attached to the roof or ground using fixings such as screws or clamps.

Once the rails are securely installed, the solar panels are attached to them using specially designed brackets or clamps. These brackets or clamps are adjustable, allowing for precise positioning and angling of the solar panels to maximize their exposure to sunlight.

The fixings used to secure the mounting system and solar panels are chosen based on the specific requirements of the installation. Factors such as the type of roof or ground, the weight and size of the solar panels, and the local weather conditions are taken into account to ensure a reliable and durable installation.

How Solar Panels Work Step By Step

Solar panels are devices that convert sunlight into usable electricity. They work by harnessing the power of the sun’s rays through a process called photovoltaics. This process involves the use of solar cells, which are made up of semiconductor materials that can absorb photons and convert them into an electrical current. By understanding the step-by-step workings of solar panels, we can appreciate how they generate clean and renewable energy.

Photovoltaic cells absorb the sun’s energy and convert it to DC electricity

Photovoltaic cells are devices that capture energy from the sun and convert it into direct current (DC) electricity.

When sunlight hits a photovoltaic cell, it causes a reaction called the photovoltaic effect. This effect occurs when photons, which are particles of light, strike the cell’s surface and free electrons from the atoms within the cell.

Once the electrons are freed, they create a flow of electricity. This flow of electrons can be harnessed and directed through an external circuit, powering devices and appliances.

Photovoltaic cells are made up of semiconductor materials, such as silicon, that have special properties. These materials have atoms with certain electrons that are more loosely bound than others. When sunlight hits the cell, these loosely bound electrons are energized and can be easily freed.

The freed electrons then move from the negatively-charged side of the cell to the positively-charged side, creating an electric current. This current can be stored in batteries or used to power homes and businesses.

Overall, photovoltaic cells work by absorbing the sun’s energy, which in turn frees electrons and creates a flow of electricity. This allows for the conversion of solar energy into usable DC electricity.

Solar inverters convert DC electricity from your solar modules to AC electricity, which is used by most home appliances

and can be fed back into the grid.

Solar inverters play a crucial role in harnessing the power of solar energy. They convert the direct current (DC) electricity generated by the solar modules into alternating current (AC) electricity.

DC electricity is produced by the solar panels when sunlight hits them. However, most home appliances and the electricity grid itself operate on AC electricity, which is why the conversion is necessary.

There are two main types of solar inverters: central inverters and micro-inverters.

Central inverters are typically used in larger solar installations. They convert the DC electricity from multiple solar modules into AC electricity at once.

On the other hand, micro-inverters are installed on each individual solar module and convert the DC electricity to AC at the module level.

Micro-inverters offer some advantages over central inverters. First, they can optimize each module’s performance independently, leading to higher overall energy harvest. They also allow for system visibility and monitoring at the module level, making it easier to detect and address issues.

In conclusion, solar inverters are essential for converting DC electricity from solar panels to AC electricity for practical use, and micro-inverters offer certain benefits compared to central inverters.

Electricity flows through your home, powering electronic devices

Electricity flows through your home to power electronic devices. When you plug in a device, electricity travels from the power station through transmission lines to your house. Inside your home, the electricity goes through a meter to measure how much you use. From the meter, the electricity enters the distribution board (fusebox).

Solar inverters are used to convert the direct current (DC) electricity produced by solar panels into alternating current (AC) electricity, which is what your home uses. The solar inverter connects to the electrical distribution board (fusebox), allowing the electricity to be fed around the house and power your lights and appliances.

The electrical board is like a control center for the electricity in your home. It distributes the electricity to different scokets and circuits. From the panel, the electricity travels through wiring to sockets, where you can plug in your devices.

When you turn on a device, like a lamp or a TV, the electricity flows through the device, powering it. Once the electricity has been used, it returns to the electrical panel through the wiring, completing the flow.

Or, if you have a solar battery the excess solar electricity will be used to power up your battery to use at night or when it’s cloudy.

In summary, electricity flows through your home, powering electronic devices (or battery). Solar inverters convert energy from solar panels, which is then dispersed by the electrical panel to outlets for use.

Excess electricity produced by solar panels is fed to the grid

When solar panels generate more electricity than is needed, the excess power can be exported to the grid (and/or fill up a solar battery). This helps to balance the overall electricity supply and demand.

To do this, a system called net metering is often used. In the UK, the net metering scheme is called The Smart Export Guarantee (SEG). Net metering allows solar panel owners to be paid by energy companies for the excess electricity they generate, it doesn’t have to be your current electricity provider. The exported electricity is measured by an export meter.

In 2024 the unit rate for electricity is capped at 24.5p per KWh, your solar electricty is free. So by powering your home with solar electricity instead of expensive grid electricity you can cut your bill by well over 50%.