Solar panels have revolutionised the way we think about energy production and consumption. These innovative devices have allowed us to harness the sun’s power and convert it into clean, renewable energy that can power homes, businesses, and even entire communities.
Two of the most popular types of solar panels are:
- Photovoltaic (PV) solar Panels
- thermal solar panels
Photovoltaic (PV) Solar Panels
One of the primary ways solar power is harnessed is through photovoltaic (PV) solar panels, which convert sunlight into electricity. They are made up of a collection of solar cells made from silicon, a semiconductor material.
PV solar panels are used in a variety of applications, from small portable devices like phone chargers to large-scale solar farms that can generate electricity for entire communities.
Origin of Photovoltaic Solar Cells
The development of photovoltaic (PV) solar cells dates back to the 19th century when the photovoltaic effect was first discovered by scientists. However, it wasn’t until the middle of the 20th century that PV solar cells were developed and became commercially available. In 1954, researchers at Bell Labs developed the first silicon-based solar cell, paving the way for the development of even more efficient and affordable solar cells.
During the 1960s and 1970s, PV solar cells were primarily used for space applications. In the 1980s, solar cells began to be used in terrestrial applications, such as powering remote telecommunications equipment and providing electricity to off-grid homes and businesses. The need for reliable power sources in remote areas and the high cost of traditional grid-based electricity drove this early adoption.
In the 1990s, advances in technology and manufacturing processes helped to bring down the cost of PV solar panels, making them more affordable and accessible to the general public. This resulted in a significant increase in the use of solar power for residential and commercial applications and set the stage for the solar industry’s rapid growth in the early 2000s.
Working Principal of PV Solar Cells
The working principle of a photovoltaic (PV) solar panel involves the conversion of sunlight into direct current (DC) electricity through the photovoltaic effect. This effect is based on the ability of certain materials, such as silicon, to absorb photons from sunlight and release electrons.
A typical PV solar panel consists of multiple solar cells connected and encapsulated in a protective material. Each solar cell contains two silicon layers, one with a positive and the other one with a negative charge. When sunlight hits the cell, it excites the electrons in the negative layer, causing them to move to the positive layer, creating a flow of DC electricity.
Types of PV Solar Panels
Solar panels have three main types:
Monocrystalline Solar Panels: These are made of a single silicon crystal, making them highly efficient at converting sunlight into electricity. They are typically black and have a uniform appearance. These are more expensive than polycrystalline panels but have a longer lifespan.
Polycrystalline Solar Panels: They are made from multiple silicon crystals, which gives them a distinctive blue colour. They are less efficient and expensive than monocrystalline panels. Polycrystalline panels are a good choice if you have limited space and want to maximise your energy output.
Thin-Film Solar Panels: These are made by depositing extremely thin layers of PV material onto a substrate, such as metal or glass. They are flexible and lightweight, making them easy to install in a variety of locations. These panels are much less efficient than crystalline panels, but they are also less expensive and have a shorter payback period.
Advantages of PV Solar Panels
Photovoltaic (PV) solar panels have several advantages that make them an attractive choice for generating electricity:
Renewable Energy: Solar energy is a renewable energy source, meaning it can be harnessed indefinitely. This makes it an environmentally-friendly option that reduces dependence on fossil fuels and decreases carbon emissions.
Low Maintenance: Once installed, PV solar panels require very little maintenance and can last 25-30 years with proper care.
Cost Savings: Solar panels allow you to generate your own electricity, which can help you save money on your energy bills.
Versatility: Solar panels can be installed on various surfaces, including walls, roofs, and even on the ground. They can also be used in remote locations where grid electricity is not available.
Longevity: PV solar panels have a long lifespan and can generate electricity for several decades, making them a smart long-term investment.
Scalability: PV solar panels can be installed in small or large arrays, allowing you to scale up your solar energy production as your needs change.
Disadvantages of PV Solar Panels
Upfront Costs: The upfront costs of installing a solar panel system can be significant, although prices have been declining in recent years.
Weather-Dependent: Solar panels generate electricity by converting sunlight into electricity. This means that they are weather-dependent and may not work as efficiently in cloudy or overcast conditions.
Space Requirements: Solar panels require space for installation, which can be a challenge for some homes or businesses with the limited roof or ground space. However, there are mounting options that can help to maximise the use of available space.
Maintenance: While PV solar panels require minimal maintenance, they still require some attention to ensure they are working efficiently, including regular cleaning to remove dirt and debris and monitoring for any signs of damage or malfunction.
Energy Storage: Solar panels generate electricity during the day, but energy storage is needed to power appliances and devices during the night or when the sun isn’t shining. This can add to the cost of a solar panel system.
Manufacturing: The production of solar panels requires energy and resources, which can have an environmental impact. However, the environmental benefits of using solar energy typically outweigh the negative impact of manufacturing.
Thermal Solar Panels
A thermal solar panel, also known as a solar thermal collector, uses sunlight to heat a fluid or air, which can then be used for space heating or hot water production. Unlike photovoltaic (PV) solar panels, which convert sunlight directly into electricity, thermal solar panels use the sun’s energy to generate heat.
Origin of Thermal Solar Panels
The origins of thermal solar energy can be traced back to the ancient era when people used the sun’s energy to heat water and cook food. The Greeks, Romans, and Chinese all used various forms of solar thermal technology, such as mirrors and lenses, to focus sunlight and generate heat.
However, in the early 20th century, solar thermal technology began to be used on a larger scale. In 1904, American inventor Clarence Kemp developed a solar water heater that was widely used in California. During the 1920s and 1930s, solar water heaters became increasingly popular in the United States, especially in the Sun Belt states.
In the 1970s, Aa a result of the energy crisis and concerns about the environmental impact of fossil fuels, interest in solar energy was renewed, and many new technologies were developed for harnessing the sun’s energy. Today, thermal solar energy is used around the world for heating water, space heating, and electricity generation.
Working Principle of Thermal Solar Panels
A thermal collector comprises a series of tubes or plates coated with a heat-absorbing material, such as copper or aluminium. These tubes or plates are filled with a fluid, such as water or antifreeze, which absorbs the sun’s heat and then circulates through a heat exchanger. The heat exchanger transfers the heat to a secondary fluid, which can then be used for heating.
Advantages of Thermal Solar Panels
There are several advantages to using thermal solar panels, including the following:
Renewable and Sustainable: Thermal solar panels are a sustainable and renewable source of energy and do not produce any greenhouse gas emissions, making them environmentally friendly.
Energy Savings: Using thermal solar panels for space heating and hot water production can reduce energy costs associated with traditional heating systems, resulting in significant long-term cost savings.
Low Maintenance: Thermal solar panels are relatively low maintenance compared to traditional heating systems, requiring only periodic cleaning and inspection.
Long Lifespan: Thermal solar panels have a long lifespan, typically lasting 20-30 years or more, making them a cost-effective investment for homeowners and businesses.
Versatile: Thermal solar panels can be used in a variety of applications, including domestic hot water production, space heating, and industrial process heat.
Improved Energy Security: Using thermal solar panels to generate heat can reduce reliance on fossil fuels and improve energy security.
Disadvantages of Thermal Solar Panels
Despite their many benefits, thermal solar panels also have some disadvantages, including:
Weather-Dependent: Thermal solar panels are reliant on sunlight to produce heat, so weather conditions, including cloud cover and low light levels, can impact their performance.
Space Requirements: Thermal solar panels require a significant amount of space for installation, which may be a challenge for homeowners with a limited roof or yard space.
Upfront Costs: While thermal solar panels can provide long-term energy cost savings, they require a significant upfront investment for installation and equipment costs.
Complexity: Thermal solar panel systems can be complex and require professional installation and maintenance, which may be challenging for some homeowners and businesses.
Maintenance: Although thermal solar panels require less maintenance than traditional heating systems, they still require periodic cleaning and inspection, which may be an ongoing cost for homeowners and businesses.
Limited Use: Thermal solar panels are primarily used for space heating and hot water production and may not be suitable for all heating applications.
Solar Panel Prices
The cost of solar panels can vary depending on different factors, including the type and size of the system, location, and installation costs. Generally, the cost of solar panels has decreased considerably in recent years, making them more affordable for homeowners and businesses.
It is important to note that while the upfront costs of solar panels system may be higher than traditional heating and electricity systems, solar panels can provide significant long-term cost savings by reducing energy bills and increasing home value.
- The cost of installing a 4kWp solar PV system can vary between £5,500 and £6,500, depending on the selected brand and installer.
- On the other hand, if a solar thermal panel of the same output size is installed into a solar-ready cylinder, the cost would range from approximately £3,500 to £4,500.
Government Schemes for Solar Panels in the UK
The UK government has several schemes to support installing solar panels and other renewable energy technologies. These schemes are designed to encourage homeowners and businesses to invest in renewable energy and reduce carbon emissions.
Feed-in Tariff (FiT):
It is a government scheme that pays homeowners and businesses for generating their own electricity through renewable sources, including solar panels. The scheme closed to new applications in 2019, but existing installations are still eligible for payments.
Smart Export Guarantee (SEG):
The Smart Export Guarantee is a replacement for the Feed-in Tariff scheme, which pays homeowners and businesses for exporting excess electricity generated by their solar panels back to the grid. The SEG requires energy suppliers with over 150,000 customers to offer a minimum payment to customers for each kilowatt-hour (kWh) of surplus energy exported to the grid.
Renewable Heat Incentive (RHI):
The Renewable Heat Incentive is a government scheme that provides financial support to homeowners and businesses that install renewable heat technologies, including solar thermal panels. The scheme offers quarterly payments over a period of seven years to those who qualify.
Green Homes Grant:
The Green Homes Grant is a government scheme that provides funding for homeowners to make energy-efficient improvements to their homes, including the installation of solar panels. The scheme offers vouchers to homeowners that can be used to cover up to two-thirds of the cost of eligible improvements, up to a maximum of £5,000.
It is worth noting that these schemes are subject to change and may have different eligibility criteria and payment rates. It is important to consult with an expert installer or energy advisor to determine which scheme is right for your specific situation.