Solar panels

Solar panels at a glance

Solar panels convert sunlight into electricity, offering a sustainable way to power your home. They can reduce your energy bills by over £1,000 annually and your CO2 emissions by almost 1  tonne. In 2023, there were over 183,000 solar panel installations in the UK, a 33% increase from 2022, highlighting the growing appeal of solar energy as an accessible renewable energy source.

Solar panels are a long-term investment, typically lasting 25–30 years, and can increase property value while contributing to energy independence.

Solar panels, also known as photovoltaic (PV) panels, convert sunlight into electricity. They’re composed of cells typically made from silicon. When sunlight hits these cells, it generates an electric current through what’s known as the PV effect.

Harnessing solar energy reduces the need to rely on fossil fuels, lowers greenhouse gas emissions and mitigates the environmental impact of traditional energy sources.

Solar panels are used in various applications, from residential rooftops to large-scale solar farms. They power homes and businesses, including in remote locations where there is no access to the grid. Solar panels can also power portable devices and vehicles.

What types of solar panels are available?

Monocrystalline solar panels

Monocrystalline panels are made from a single piece of silicon, which makes it easier for electricity to flow through them. They’re typically black in colour, and have a lifespan of up to 40 years if properly maintained. 

• Efficiency: Typically the most efficient type of solar panel, ranging from 16% to 22% efficiency or more.
• Cost: Around £1.00 to £1.50 per watt.
• Best for: Homeowners looking for a high power output and smaller system footprint.

Polycrystalline solar panels

Polycrystalline solar panels are constructed from multiple fragments of silicon crystals melted together to form sections called cells. Silicon fragments, even when melted together, are prone to surface imperfections, which prevents the electricity flowing as freely as with monocrystalline panels. Poly panels have a blueish hue, and a slightly shorter life expectancy than monocrystalline panels.

• Efficiency: Slightly lower than monocrystalline panels, typically 15% to 17%.
• Cost: Around £0.90 to £1.00 per watt, less expensive than monocrystalline panels.
• Best for: Those who want a more budget-friendly but effective option.

Bifacial solar panels

Bifacial panels can capture daylight from both sides of the panel, increasing total energy generation.

• Efficiency: In ideal conditions, they can produce up to 30% more energy than traditional panels.
• Cost: The most expensive type of solar panel due to their higher efficiency.
• Best for: Installations where the reflective surface under the panel can enhance energy production, such as homes with metal roofs.

Thin-film solar panels

Thin-film panels are constructed by attaching very thin silicon layers onto a flexible but robust film.

• Efficiency: Generally the lowest efficiency, about 10% to 13%.
• Cost: Between 40p and 80p per watt.
• Best for: Large commercial spaces or buildings with roofs that can’t support heavier panels. Because of their lower temperature coefficient, they’re also suitable for areas with vastly variable temperatures.

Are solar thermal collectors the same as solar panels?

A thermal collector, also known as a solar thermal system, harnesses solar energy for heating water in homes. Unlike PV systems that convert sunlight into electricity, solar thermal systems directly convert sunlight into heat.

The system is typically made of fluid-filled tubes, although flat thermal panels filled with fluid are also seen. The sun’s energy heats the fluid, which in turn heats your water stored in an insulated water cylinder ready for domestic use, such as showers, heating swimming pools, or your central heating. These systems are efficient, eco-friendly, and can significantly reduce reliance on conventional energy sources for heating water. They can be used alongside solar PV panels.

When sunlight hits the solar panel, it heats up and activates electrons within the silicon cells, generating direct current (DC) electricity. This current then travels along bus bars – metal strips that connect the panel’s cells – and arrives at the inverter. The inverter converts DC electricity into alternating current (AC), which can power your home.

Can solar panels work by themselves?

While solar panels are the core component of a solar energy system, they work as part of a comprehensive setup that includes several other critical elements. Solar panels generate DC electricity from sunlight, but this is just one piece of the puzzle. Here’s a look at how they function within a complete system:

Inverter

An inverter is needed to convert the DC electricity produced by solar panels into the AC electricity needed for use in your home. This conversion is essential because most household appliances operate on AC power.

Monitoring system

Advanced monitoring systems provide real-time data on solar panel performance, energy production and consumption. This information helps optimise solar energy use, identify issues promptly and ensure that the system operates at peak efficiency.

Mounting system

The mounting hardware includes the racks and fixtures needed to secure solar panels on a roof or the ground. Proper mounting is crucial for maximising the panels’ sun exposure and electricity production.

Grid connection

Although not mandatory, connecting your solar system to the electrical grid offers several benefits. When your solar panels produce more electricity than you need, the excess can be fed back into the grid, potentially earning you credits or payments through schemes such as the Smart Export Guarantee (SEG). Conversely, a connection to the grid allows you to draw power from it when your system isn’t producing enough electricity.

Diverter

A solar diverter is an optional extra designed to optimise your energy usage. It directs excess electricity generated by the solar panels to specific loads or appliances, typically to heat water, rather than exporting it back to the grid, improving the overall efficiency of your solar panels.

Combining solar panels with a diverter offers a cost-effective alternative to solar thermal systems, which require a water tank for operation.

Charge controller

A charge controller is particularly important for systems with solar batteries. It regulates the voltage and current from the solar panels to the battery, protecting the batteries from overcharging and helping prolong their life.

Do I need a solar battery?

A battery system

 can be integrated to maximise the benefits of solar panels, especially when it’s cloudy or at night. Batteries store excess energy generated during peak sunlight hours, allowing you to use this stored energy when solar production is low or demand is high. However, batteries will typically need to be replaced every 10 years.

A typical solar battery is the size of a small microwave oven and can be positioned in a garage, utility room, or loft. Some batteries can also be secured outside. According to our research, around 90% of solar systems include a battery, allowing homeowners to minimise their reliance on the grid.

Solar panels typically convert upwards of 20% of solar energy into usable energy in the UK. They convert more solar energy when absorbing direct sunlight, but they can still produce electricity on overcast days because any visible light stimulates them. Put simply, if it’s light enough to see a solar panel, it’s light enough to generate electricity.

However, some areas of the UK receive more sunlight than others, making them ideal for solar energy production. Southern regions generally see better performance due to higher sun exposure, while solar panels in northern areas may experience slightly lower efficiency rates.

According to Government data, 88% of solar system adopters in the UK are in England, the majority in the South (39%), compared to 21% in the North. An additional 5% of adopters hail from Wales, and Scotland has a slightly higher take-up of 6%.

Solar panels for homes can cut your energy bills and reduce your carbon footprint, but they also have a number of other benefits.

• Reduced energy bills: Generating electricity through solar panels can reduce your energy bills by £1,000 or more.
• Constant supply of electricity: Solar panels generate clean electricity all year round, lasting up to 25 years or more. If you install a solar battery, you’ll still have an electricity supply in the event of a power cut.
• Increased home value: Installing solar panels could increase the value of your home by up to 25%.
• Sale of solar energy back to the National Grid: You could sell surplus energy from your system back to the grid through an SEG tariff.
• Reduced carbon footprint: Solar panels generate clean, renewable energy, significantly reducing reliance on fossil fuels and lowering greenhouse gas emissions. This clean energy transition contributes to combatting climate change.

Are solar panels really good for the environment?

Government studies and independent research consistently show that solar panels positively impact the environment. According to the UK Department for Business, Energy and Industrial Strategy, solar panels significantly reduce carbon emissions by generating clean, renewable energy. A 2021 study by the UK Government indicated that solar energy systems could reduce a typical household’s carbon footprint by approximately 1.5 to 2 tonnes of CO2 per year.

However, the production of solar panels involves energy-intensive processes and the use of materials that can negatively impact the environment. Despite this, solar panels’ overall lifecycle emissions are much lower than conventional energy sources.

Solar panel recycling is a critical aspect of their environmental impact. Recycling technologies are improving, and the UK is developing better infrastructure to handle end-of-life solar panels. According to a report by the International Renewable Energy Agency, up to 96% of the materials in solar panels are recoverable and reusable, reducing the long-term environmental footprint of solar technology.

When considering installing solar panels, aside from the amount of sunlight your property receives, you should also consider the condition and orientation of your roof and your household’s energy consumption.

Determining the number of solar panels you need for your home depends on several factors, including your energy consumption and the size and efficiency of the panels. 

Power output is measured in watts (W) or kilowatts (kW), and a typical panel’s output is between 300 and 400 watts (0.30 kW–0.40 kW). Generally, the higher the power output, the fewer panels you’ll require; however, it’s worth noting that highly efficient panels tend to be more expensive.

What impact does my roof have on solar energy production?

Your roof’s type, condition, orientation, pitch, and shading all play crucial roles in determining the feasibility of a solar panel installation.

• A south-facing roof is ideal: Solar panels produce the most energy when they face south. However,  many modern panels generate electricity from all daylight, with only a slight reduction in output when they’re not south-facing.
• The angle of your roof matters: Solar panels have an optimal roof angle of between 30 and 45 degrees. If you have a flat roof, you can still install a system, but you will need a mounting system to hold the solar panels at the optimal angle.
• A good amount of roof space is required: The size of your roof will determine the size of your solar power system. However, with new technology, panels are increasing in power output while decreasing in size.
• The roof should be in good condition: A solar panel system adds extra weight to your roof, so you should have your roof assessed for broken tiles or damage before installation. Most good installers will do this.

The efficiency of solar panels varies depending on which region in the UK you live in, as each area gets varying degrees of sunlight. Our researchers have used the daily sunlight hours recorded by the Met Office in 2023 for each UK region to calculate the monthly energy output you can expect from a typical 4kW solar panel system.

The charts below outline the average monthly energy output of a 4kW system in all UK regions (data source: Met Office).

North East England

East England

Midlands

London and South East England

South West England and South Wales

North West England and North Wales

Northern Ireland

Scotland

The type of house or area you live in can significantly influence the feasibility, cost and efficiency of installing solar panels.

Generally, you can install solar panels under permitted development rights, meaning most homes don’t need planning permission. The UK Government updated these guidelines in 2023 to make installing solar panels on flat roofs easier. However, you must meet some conditions.

• Minimal impact: The system must minimise changes to the building’s exterior and the area’s aesthetic.
• Removal: You must remove the system when it’s no longer needed.
• Height limit: The system can’t exceed the roof’s highest point (excluding chimneys).
• Protrusion: The system must not extend more than 0.2 metres beyond the roof slope or 0.6 metres on flat roofs.

Always consult your local planning authority for guidance if you’re unsure. Certain situations may require consent or planning permission, including properties in conservation areas.

Flat roofs

Installing solar panels on a flat roof sometimes requires planning permission because the panels are typically mounted in angled frames to capture sunlight. This setup usually results in the panels extending more than 0.6 metres above the roof slope, which exceeds the limits set by permitted development guidelines.

Listed buildings 

Installing solar panels on a listed building often requires strict compliance with heritage regulations. For these buildings, the first step involves obtaining listed building consent to ensure that the solar installation aligns with the building’s historical and architectural significance and minimises its visual impact. Following this, an application for planning permission must confirm that the solar panels will not detract from the area’s overall aesthetic or heritage value.

The consent process involves consultations with the local planning authority, which may impose specific requirements, such as a requirement that the panels be placed in less visible locations or made from non-reflective materials. Working closely with conservation officers and understanding the guidelines ensures the solar installation maintains the listed building’s integrity while incorporating renewable energy solutions.

Conservation areas

If your property is in a conservation area, certain restrictions apply to preserve the area’s historic and aesthetic value, so you’ll usually have to apply for full planning permission. For example, some planning authorities may permit a solar system as long as they aren’t visible from any roads. This measure minimises the visual impact of new installations on the conservation area’s character.

It’s crucial to consult your local planning authority early in the approval process. They can provide specific guidelines regarding the positioning and materials for solar panels to blend with the surrounding architecture. Emphasising non-intrusive installation strategies, such as rooftop panels not visible from the street or ground-mounted arrays shielded by natural barriers, can increase the likelihood of obtaining permission.

Electric vehicles

Electric vehicles (EVs) are primarily electric batteries on wheels. By integrating solar panels with your home, you can harness renewable energy to charge your EV, significantly reducing fuel costs.

Installing a dedicated EV charging station at your home and connecting it to your solar system ensures your EV is using free, clean energy. Combine your system with battery storage, and you can use this stored energy to charge your EV at night or during periods of low sunlight.

Heat pumps

A heat pump is a low-carbon heating system powered by electricity. Using a solar panel system to power your heat pump can significantly reduce your electricity and heating bills.

Air source heat pumps are the most popular type and cost around £14,000 to install.

Using your energy efficiently

If you’re out at work during the day, you’ll be unable to take advantage of the energy generated by your panels, and without a battery to store it, the unused electricity will be sent to the grid.

Setting timers for energy-hungry appliances, such as dishwashers and washing machines, to run during peak production periods is a cost-effective solution. On average, energy companies will pay you around 12p for every unit of electricity sent to the grid under the SEG scheme, while electricity is purchased at approximately 28p per unit. As a result, it makes more sense to use the energy yourself by storing any excess in a battery instead of selling it.

The cost of installing solar panels on the roof of a typical 3-bedroom property is between £8,500 and £9,100, including a battery. 

What drives the price of solar panels?

• Solar panels: The panels themselves make up around 33% of the total installation cost.
• Inverter: Inverters typically cost 10% of the total.
• Battery:An optional addition, the battery cost varies depending on its storage capacity. A model suitable for a 3-bedroom property costs between £2,000 and £2,500, which equates to approximately 20% of the overall installation cost.
• Electrics: Electrical components make up about 8% of the cost.
• Mounting hardware: The rails and other hardware comprise about 15%.
• Labour:The size and complexity of the system dictate the cost of labour, which is about 9%.
• Documentation: The required documentation is around 5% of the final figure.

Learn more about the cost of solar panels in our guide to solar panel costs.

There are several ways to fund the installation of your solar panels. 

Upfront payments

If you have the cash, paying the total installation cost upfront is the simplest option. This method has the advantage of ensuring that you do not need to pay interest, and because you own the panels outright, moving home presents no complications. However, by buying the panels upfront, you are responsible for any maintenance costs.

Subscriptions

Subscription plans are an increasingly popular payment method. From as little as £20 per month, you can benefit from solar energy, and many solar providers now offer this option.

Depending on the plan, you might not own the solar panels outright and could therefore miss out on certain incentives or property value increases. Typically, plans include maintenance and may also include battery replacement after ten years.

Loans

Solar loans function similarly to other loans, enabling you to install solar panels by making regular repayments over time, and many installation companies offer flexible payment plans. However, you can often secure a better interest rate by taking out a loan from a financial institution instead of a solar panel provider.

Green mortgages

Mortgage lenders increasingly offer funding options for home improvements that focus on renewable resources such as solar panels. Many green mortgages come with lower interest rates than traditional ones, making the overall cost of borrowing cheaper, and there may be additional incentives such as reduced fees or cashback for energy-efficient improvements.

Installing solar panels can save you a substantial amount on your energy bills. The exact savings depend on various factors, including your system size, energy consumption and electricity rates. With high potential annual savings and long-term benefits accumulating over the system’s lifespan, solar panels can be a financially wise investment.

There are many options for getting financial help to install solar panels in the UK.

Zero VAT on solar panels

The government’s Spring Statement 2022 announced a drop from 5 per cent to 0 per cent VAT for new solar panels until March 2027 – a saving of £340 on an average system.

Energy Company Obligation (ECO4) scheme

The ECO4 scheme is the latest phase of a government plan to support low-income households by creating more energy-efficient homes. Until 2026, you can apply for solar panel grants, which could, depending on your circumstances, give you access to fully funded solar panels for home installation.

LA Flex scheme

Local Authority Flexible Eligibility (LA Flex) is an extension of ECO4. With LA Flex, you can qualify for free funding to cover the costs of energy-saving measures, such as solar panels for homes running on electric heating systems.

Find out more in our article Solar panel grants in the UK.

The SEG allows you to export surplus energy to the National Grid and receive payment from the energy companies. Currently, there are no caps on the amount of energy you can export to the grid: you can sell as much or as little surplus electricity as you wish.

Each energy supplier sets its own rate for the electricity it buys from you. There’s no fixed minimum rate, but suppliers must offer a rate above zero, so compare offers to get the best deal. You can get a fixed rate, which remains the same throughout your contract period, or a variable rate, meaning it may fluctuate based on market conditions.

The cost of solar panels is still relatively high, and although homeowners will start saving on their energy bills quickly, it’s important to know when you’ll break even. This is the point at which your panels have paid for themselves and includes the initial panel cost minus your energy bill savings and any SEG payments you receive.

Including a battery can significantly reduce the break-even point by allowing you to store home-generated electricity to use whenever you need it, such as overnight, reducing your reliance on grid-supplied energy and increasing your savings.

Investing in solar panels can lead to significant savings over their lifespan, with the break-even point generally occurring within 11 years. After this period, the savings continue to accumulate, providing a considerable return on your initial investment.

While buying solar panels from Amazon at a lower upfront cost might be tempting, this approach can lead to several issues, including improper installation, lack of support and potential safety hazards.

Purchasing solar panels from a reputable installer ensures you receive professional expertise, quality assurance, proper installation, compliance with regulations, post-installation support and access to financial incentives.

How do I pick the right panel?

Most installers will have their preferred solar panels based on their expert knowledge and experience. However, it’s essential that you also know what to look for.

When selecting a panel, look for models offering at least 20% efficiency and delivering a power output of over 420W. Monocrystalline panels provide superior efficiency compared to polycrystalline options, while bifacial panels capture the maximum amount of sunlight.

Other factors to consider include:

• Product warranty (typically 20-25 years)
• Low light performance
• Weather resistance
• Cost

Which solar panels are considered the best?

After comparing and assessing top-level panels, our experts recommend the Project Solar Evolution Titan 445 as the overall best solar panel. This bifacial model delivers a power output of 445W and efficiency of 21.01% and includes a lifetime warranty.

Finding the right installer is crucial to ensure a smooth and efficient installation. 

There are several ways to do this:

• Complete our form to receive free, no-obligation quotes from our trusted installers.
• Speak to neighbours who have solar panels installed. Their firsthand experience can provide valuable insights and recommendations.
• Some energy providers provide a list of recommended or partnered installers who have met specific standards of service and reliability.
• Organisations, such as the MCS or Renewable Energy Consumer Code offer directories of accredited installers.

Deciding between a national or regional solar panel installer really comes down to your specific needs and preferences. A national installer might be the way to go if you value extensive experience and a well-established track record. They often offer comprehensive warranties and have the infrastructure to support widespread service demands.

On the other hand, if personalised service and local expertise are more important to you, a regional installer could be a better choice. They typically have a deeper understanding of local regulations and incentives and may provide more tailored and responsive customer service.

As such, you should consider what aspects of the service and installation process are most crucial to you and choose the company that best meets those needs.

Can I install solar panels myself?

Although installing solar panels yourself is technically possible, it’s generally not recommended unless you have specific technical skills and experience. Solar panel installation involves complex electrical work, safety considerations and precise alignment to maximise energy efficiency.

Here are a few other reasons why DIY installations might not be the best idea:

• Compliance and incentives: Solar installations must comply with specific standards such as those of the MCS. The MCS certification is crucial for quality assurance and is often required to benefit from governmental incentives like the SEG. DIY installations typically only qualify for these incentives if they’re certified.
• Warranties: Improper installation can lead to premature wear and damage, potentially voiding the warranties provided by solar panel manufacturers and installation companies.

How long does the installation process take?

From choosing an installer to having operational panels on your roof, the solar panel installation process can vary widely based on several factors, such as the complexity of your system and the installer’s schedule. However, here’s a general timeline you might expect.

Choosing an installer 

This initial step can take a few days to a few weeks. It involves researching different companies, comparing quotes and deciding on the installer that best fits your needs.

Site assessment and design

Your installer must conduct a site assessment to evaluate your home’s roof structure, sun exposure, and any potential shading issues. They will also discuss your energy needs and goals. This stage can take from 1 to 2 weeks, including the time needed to design the system.

Permits and documentation

The installer will handle the permits and paperwork required by the authorities and utility companies. This process can be quite variable, taking anywhere from a few days to several weeks, depending on local regulations and the efficiency of the permitting process in your area.

Installation

The actual installation of the solar panels usually takes only a few days. Most residential solar installations take 1 to 3 days, depending on the size and complexity of the system.

Inspection and connection

After installation, a local building inspector and a utility representative must inspect the system to ensure everything is up to code and safely installed. This could take a few days to a week. Following approval, you can connect your system to the grid.

Activation

Finally, once you pass all inspections and connect the system to the grid, your installer will activate your solar panel system. This is usually a quick process, often just a matter of flipping a switch once everything is approved.

Solar panels are relatively low maintenance, but proper care is essential to maximise efficiency and lifespan. Green Journal suggests panels coated in dust can lose up to 3% of their efficiency.

Here are some tips and maintenance practices that can help extend the life of your solar panels.

Regular cleaning

Dust, debris and other materials, such as bird droppings, can accumulate on your solar panels and reduce efficiency. You should clean your solar panels once every 6 months. The best times are usually at the end of spring – to prepare for the high energy-producing summer months – and the end of autumn.

Use a soft brush or a non-abrasive sponge and a mild detergent to clean the panels gently.

Monitor performance

Keep an eye on your solar system’s performance through the monitoring system that most installations include. A sudden drop in energy production can indicate a problem, such as an obstruction or damage to a panel.

Pest prevention

Sometimes, birds can nest under or around solar panels, potentially damaging the wiring. If this becomes an issue, consider installing pest deterrents.

Shade checks

As trees grow, they can cast shade on your panels, which might not have been an issue when you installed the panels. Regularly check for and manage vegetation around your solar array to ensure clear exposure to sunlight.

Annual inspections

Although solar panels are durable, it’s a good practice to have them inspected by a professional annually. This check-up can identify potential issues, such as loose mountings, shading from new vegetation growth or wiring problems, before they become major.

Can I maintain my solar panels myself?

You can maintain your solar panels yourself, especially regarding routine tasks such as cleaning and visual inspections.

However, it’s advisable to call in a profession for more technical aspects, such as electrical inspections, repairs or dealing with issues that a simple cleaning can’t resolve. This ensures safety and helps maintain the warranty conditions that unprofessional handling could void. Plus, professional solar maintenance personnel can spot potential problems that might not be obvious to the untrained eye.

Considering solar installation benefits, solar panels are a good investment for most homeowners. They save significant money on your electric bill, especially if you include a battery. You can also sell any surplus electricity back to the National Grid. This means that, over time, solar panels will pay for themselves.

Additionally, solar installations can increase property values, making them appealing for future real estate transactions. Beyond the financial benefits, choosing solar energy significantly reduces reliance on fossil fuels, contributing to environmental sustainability. Therefore, solar panels can offer substantial economic and environmental returns.