By Jonathan Whiting

✔ A solar panel system for a family of three costs about £4,000-£6,000

✔ Solar panels can reduce your monthly energy bills by up to 50%

✔ Fill out the form above to get solar panel quotes from trusted local installers

DISCLAIMER: Our partners no longer take appointments for homeowners looking to benefit from the Feed-in Tariff, which concluded on 31st March 2019

Solar panels are great. Once you’ve had them installed, the electricity they make is free, renewable and environmentally-friendly. In fact, it actually earns you money – and adds an average of 4.1% to your property’s value.

Solar panels can seem expensive and you might be wondering whether you should get them; this guide will give you everything you need to know, including how they work, their pros and cons, rough costs and the leading solar panel manufacturers.

To start receiving free quotes for solar panels, simply fill in this short form, and our suppliers will be in touch.

What’s in this Guide to Solar Panels?

Solar Panels: The Basics

There are 2 types of solar panel: photovoltaic (PV) panels and thermal panels. The former generate electricity; the latter just heat water. This page is about photovoltaic panels.

Photovoltaic means that the panels produce electricity when they are exposed to light. This electricity provides power for your home.

But unlike with mains electricity, the supply from your solar panels isn’t unlimited; they only have a certain capacity. That’s not a problem, because you’ll still be connected to the National Grid, so if you need more electricity than your solar panels are providing, your home will automatically just start drawing electricity from the Grid instead. This makes no practical difference – you won’t even notice it happening. But you’ll have to pay for electricity from the Grid, so your solar panels won’t do away with your electricity bills completely, they’ll just reduce them.

On the flip side, though, if you don’t need all the electricity the panels produce, it isn’t wasted – it’s sent to the National Grid for someone else to use. And you get paid for this.

Even better, in England, Scotland and Wales, the Government also pays you just to have solar panels. Your energy company pays you – tax free – for all the energy you produce for the first 20 years of having solar panels, even if you use it yourself. So you’re paid for all the energy you generate, and if you then send some of it back to the Grid, you’re paid for it again.

The payments you get for generating electricity are called the Generation Tariff, and the payments you get for selling the electricity back to the Grid are called the Export Tariff. Together, they’re known as the Government Feed-in Tariff. Northern Ireland has a slightly different system, called the Northern Ireland Renewables Obligation Certificates (ROCs).

Still want more information? This video provides you with a short rundown of everything you need to know about solar panels.

How Do Solar Panels Work?

A solar panel works by what’s known as the photoelectric effect – the fact that some materials emit electrons when light is shone on them.

Inside each solar cell are 2 thin layers of silicon crystal. Both layers have been interfered with slightly so that their atoms are unstable. The atoms on the top layer all have 1 electron too many, and the atoms on the bottom layer all have too few electrons. Atoms don’t like having the wrong number of electrons, so the top ones are keen to get rid of their extra electrons, while the bottom ones are eager to acquire some.

However, the electrons need to be exposed to sunlight to give them the energy to get moving. And when electrons move, they create an electric current. At this stage, the electricity will be DC (direct current) – the kind of electricity you get in batteries – so you’ll have a device called an inverter, which turns it into AC (alternating current) electricity, the kind that comes off the mains and powers your home’s appliances.

But this is Britain… it’s always raining!

As long as there’s daylight, solar panels will work; the sun doesn’t need to be beating down. In fact, we’ve created a guide on the best conditions for generating solar energy.

The panels won’t, of course, work as well on a cloudy day, and they won’t work when it’s dark, so you’ll use electricity from the Grid at night (unless you have a solar battery).

What Are the Advantages and Disadvantages of Solar Panels?

Advantages

✔ Money saving. The electricity from your solar panels is free, meaning you can save money on your energy bills. Plus you get paid through the Feed-in Tariff for the electricity you generate. If you’re wondering how much you could save with solar panels, check out our guide on whether they’re a good investment.

✔ Renewable energy. Sunlight will never run out, unlike fossil fuels, which are still our main source of energy.

✔ No pollution. Solar energy doesn’t generate carbon dioxide or contribute to global warming. According to the Energy Saving Trust, a typical home solar power system could save around 1.5 to 2 tonnes of carbon each year.

✔ Easy to look after. Solar panels are easy to install and require almost no maintenance as they have no moving parts. You may need to clean them from time to time, but the rain may do that job for you. See, Britain is perfect for solar panels after all!

✔ Off-Grid energy. If your home isn’t connected to the National Grid, solar panels are a straightforward way to generate your own electricity.

Disadvantages

✘ High initial cost. Solar panels can cost several thousand pounds upfront – see our table below.

✘ Weather dependent. They’re less efficient in cloudy weather and don’t work at night, which also means they won’t provide as much electricity in the winter, when there is less daylight.

✘ Physical appearance. Solar panels will alter the appearance of your house and this is not to everyone’s taste.

You can read more about the advantages and disadvantages of installing solar panels on our pros and cons page.

Are Solar Panels Suitable for Your Home?

First, you need to have a roof (and we’d hope your home has one!) – and the bigger and more exposed to the sun it is, the better. Solar panels work best on south-facing roofs, but also work reasonably well on east and west-facing roofs. But on a roof that is north-facing or very much in the shade, they may not get enough sunlight to make the cost of installing them worthwhile. For most homes, however, solar is a viable option.

Solar panels can be installed in blocks of flats, but you’ll need to find out whose permission you need as even if you own the flat, you may not own the freehold.

You don’t usually need planning permission to install solar panels, unless you live in a conservation area, listed building or World Heritage Site. In these cases, you should check with your district or borough council if you have consent. You should also let your home insurer and your mortgage company know that you plan to install solar panels.

What Size Solar Panels Do You Need?

The power of solar panels is measured in kWp: kilowatts peak. The kilowatt is a measure of electrical power, so the kWp figure tells you how much power the panels can produce when they are operating at their maximum capacity. This will be when it is sunniest.

A typical domestic system will be between 1kWp and 4kWp. Obviously, the more powerful your system, the more electricity it will generate, but the more expensive it will be to install (although this won’t increase exponentially, because double the number of solar panels doesn’t equate to double the work to install). Once you get over 4kWp, the Feed-in Tariff rate isn’t usually as good. As a rough guide, for each kilowatt, you’ll need about 7 square metres of roof space. You can read more about what size panels you need for your home here.

The amount of electricity the system generates in a year is measured in kilowatt hours (kWh). Each kWp should generate around 800 to 850kWh per year. So based on the figures in the previous paragraph, a typical domestic system would be likely to generate between 1,200kWh and 3,200kWh per year.

The Energy Saving Trust estimates that an average 3-bedroom family home in the UK uses around 3,000 kWh of electricity per year.

Your annual 3,400kWh from a 4kW system would give you: 4,856 hours of the washing machine (202 days without stopping – that’d even get red wine stains out) 7,142 hours of the fridge (so you could run 11 fridges for the whole year) 1,880 hours of boiling the kettle (22,560 cups of tea) 1,417 hours of the oven (2,834 cakes)

Your solar panels will come with a meter, which will show you exactly how much electricity they’re producing and how much you’re selling back to the Grid.

Check out this guide if you’re still unsure as to how many solar panels you’ll need for your home.

How Much Do Solar Panels Cost in the UK?

Solar panels aren’t cheap – but they’re not meant to be. They’re a long-term investment which, once you’ve had them installed, will cut your electricity bills and reduce your carbon footprint every day for several decades.

They can cost anywhere between £1,500 and £8,000. As a rough guide you can expect to pay:

Size Output Cost 1kW solar panels 750 to 850kWh per year £1,500 to £3,000 2kW solar panels 1,700kWh per year £3,000 to £5,000 3kW solar panels 2,550kWh per year £4,000 to £6,000 4kW solar panels 3,400kWh per year £6,000 to £8,000

If this looks like a very wide price range, it’s because so many variables will affect the cost: the type of panel, the manufacturer, the size of your home and your family. You can get a much more accurate estimate by getting a quote from one of the trusted suppliers we recommend – or have a look at our solar panels prices page.

Can You Get a Grant to Install Solar Panels?

The Government doesn’t offer grants, because it remunerates you through the Feed-in Tariff. However, there is some financial help available through the government’s ECO scheme. The Scottish Government also offers some interest-free loans for homeowners who want to install renewable energy systems.

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How Much Can You Save with Solar Panels?

DISCLAIMER: Our partners no longer take appointments for homeowners looking to benefit from the Feed-in Tariff, which is due to end on 31st March 2019

Based on the current Feed-in Tariff rates, solar panel owners are paid 3.86p per kWh for the solar energy they generate (the Generation Tariff), and 5.24p per kWh for the energy they sell back to the Grid (the Export Tariff). So if you have a 3kW system, that’s around £100 a year you’re getting paid for generating renewable electricity – plus whatever you earn from the Export Tariff.

If you live in England, Scotland or Wales, these rates apply if your home has an EPC energy efficiency rating of D or above. If not, you won’t earn so much from the Feed-in Tariff.

84% of homeowners we surveyed save up to 50% on their monthly energy bills with their solar panels*

*Based on a survey we conducted in January 2018 of 390 UK homeowners with solar panels.

This is how much we’d expect you to save each year with solar panels (based on a monthly electricity bill of £50):

Size Cost Annual Payment from Generation Tariff Annual Payment from Export Tariff Annual Electricity Bill Savings Total Annual Savings 1kW solar panels £1,500 to £3,000 £35 £24 £53 £112 2kW solar panels £3,000 to £5,000 £70 £48 £78 £196 3kW solar panels £4,000 to £6,000 £105 £71 £93 £270 4kW solar panels £6,000 to £8,000 £140 £95 £104 £339

Solar Panel Installation

It usually takes between 1 and 2 days to install solar panels, but it can take a little longer for more complex jobs. For example, if your roof has fragile tiles made of slate or clay, you should be prepared for your installation to take up to 3 or 4 days.

You’ll need scaffolding erected around your house a couple of days before your solar panel installation so that the workmen can access your roof. Most installers will arrange for the scaffolding to be put up for you, but you might need to organise it yourself.

On the day of the installation, a mounting frame – made up of parallel aluminium bars – is attached to your roof using a specially engineered locking system, to make sure that it doesn’t move (even in the high winds of British wintertime). Your solar panels will then be fixed onto the frame with clamps.

When all of your solar panels are fixed in place, they’ll be connected to an inverter – a bit of technology that converts the electricity generated by your solar panels into electricity that can be used to power your home. The inverter is usually installed in your loft and is connected to the rest of your home’s electricity supply.

Your solar panels will then be switched on and checked to make sure everything’s working properly.

Good to know: make sure you have a surveyor visit your property to check the integrity of your roof. You’ll want to make sure that your roof is able to support the weight of solar panels before having them installed.

How Long do Solar Panels Last For?

Solar panels often have a 25-year guarantee, but should last for longer than that – probably between 35 and 50 years. The solar inverter will likely need replacing after 10 to 15 years, or maybe sooner; inverters cost from around £500.

Types of Solar Panel

All photovoltaic products work the same way, but it’s worth understanding the difference between the different types of solar panels:

Monocrystalline solar cells are the most compact and efficient, but also the most expensive. They generally have a longer lifespan than polycrystalline cells and thin film cells, and their efficiency tends to be less affected by higher temperatures.

Polycrystalline solar cells are cheaper than monocrystalline, but less efficient and compact. Monocrystalline and polycrystalline panels are the most widely used and widely tested.

Thin-film solar panels are less efficient still, naturally, this is reflected in the price. They are very thin – hence the name – but the actual size of the panels are large, meaning they’re not always suitable for houses. They also tend to have a shorter lifespan than crystalline cells. However, they are better at working efficiently in cloudy and dim conditions.

Solar tiles actually replace the tiles on your roof, instead of being placed on top of it, and are designed to fit in with your roof’s appearance. Solar roof tiles are more expensive and less efficient than panels because they are fairly small, but they may be suitable for listed buildings where other options aren’t as they are less noticeable.

You can also get caravan solar panels and solar panels for boats.

What Are the Best Solar Panel Brands?

When buying solar panels, you want to make sure they’re high quality, both in terms of build and performance; this’ll maximise your return on investment. We’ve independently reviewed over 20 solar panel brands to bring you a rundown of the best solar panel manufacturers on the market today. Check out who made the list below and compare some of the key information about their solar panels.

Brand Number of Solar Panel Models Types of Solar Panel Solar Panel Efficiency Solar Panel Power Warranty Canadian Solar 28 Polycrystalline 15.81% to 18.63% 25 to 30 years LG 13 Monocrystalline 16.8% to 21.1% 25 years Panasonic 4 Monocrystalline 19% to 21.6% 25 years Sharp 11 Monocrystalline, Polycrystalline 16.5% to 20% 25 years SolarWorld 4 Monocrystalline 14.91% to 17.59% 25 years Yingli Solar 20 Monocrystalline, Polycrystalline 15.3% to 20.5% 25 to 30 years

If you want to find out more about any of these brands and the solar panels they make, visit our guide to the best solar panels.