Are solar panels worth it in the UK?

Before you buy solar panels for your home, you’ll want to find out whether they’re worth the investment.

Using the sun to generate free, green energy can cut your electricity bills, reduce your carbon footprint, and protect you against energy price rises – but it comes at a cost[1].

In this guide, we’ll explain how much solar panels usually save households, when you can expect to break even, and all the factors that’ll influence your return on investment.

If you’re wondering how much a solar & battery system could save you, just answer a few quick questions below and we'll generate an estimate for you.

Is it worth getting solar panels?

It’s absolutely worth getting solar panels.

They’ll cut your annual electricity costs by up to 103%*, saving you hundreds of pounds per year and tens of thousands of pounds over their lifespan.

This high level of savings means a solar & battery system will typically break even in just seven years, and protect you against energy prices rising in the future.

Solar panels also raise your home’s value – and they do all of this while also shrinking your carbon footprint by a tonne of CO2 per year.

*Our savings estimates are based on a household experiencing average UK irradiance with a 4.4kWp solar panel system and a 5.2kWh battery, using 3,500kWh of electricity each year and signed up to the Intelligent Octopus Flux export tariff.

How long does it take for solar panels to pay for themselves?

It takes seven years* for a solar panel system to pay for itself, on average.

This varies substantially across different installations though, in both directions.

We’ve created designs for households in Bedfordshire and Sheffield which both have a payback period of 5.8 years, and another design for an Exeter property that breaks even after just 4.8 years.

All these designs are well-sized for how much electricity each household uses, are in locations which receive more daylight than average, and have roofs under limited shade.

On the other hand, we’ve designed systems for homes in Durham and Dewsbury that come with payback periods of 11 and 12 years, respectively.

Solar panel systems in these more northern locations will generally take longer to break even, as they don’t enjoy as much daylight as southern and eastern regions.

These were also slightly oversized systems, which usually pushes the break even point back.

It’s common for a homeowner to request a bigger system than they currently need, because they plan to purchase devices like an electric vehicle or heat pump.

Until they make these additions, their payback period will be longer – unless they’re using Intelligent Octopus Flux, which pays the same amount for the electricity you export as it charges for the electricity you import.

On this tariff, a solar panel system that generates far more electricity per year than your household uses will still break even quickly, while also making massive lifetime savings.

*Our payback estimate is based on an average of 32 different solar & battery system designs from Sunsave’s database, comprising properties from all over England and Wales. Each system in this sample uses 430 W solar panels and a 5.8 kWh battery, and is signed up to the Octopus Flux export tariff.

What factors affect the payback period of solar panels?

Multiple factors affect the payback period of solar panels.

You can often control a large number of these considerations – and you should take every reasonable step you can to do so.

For instance, you might not be able to affect how much daylight hits your roof, but you can choose one of the best solar panel installers around.

Here are all the factors that can change your payback period:

• The size of your solar panel system
• The efficiency of your solar panels
• How much daylight hits your panels
• How quickly your solar panel system’s efficiency degrades
• The amount you paid for your system
• The price of grid electricity
• Your total annual electricity consumption, and whether it changes
• Your daily and annual usage patterns
• Whether you’re on one of the best export tariffs or not
• How often (and how much of) your solar panel system is under shade
• The amount of dust and debris on your panels
• Your roof’s angle and direction
• Whether your solar panel system experiences any downtime
• Whether your system uses string inverters or microinverters
• Whether or not you have a solar battery
• Your solar battery’s size
• How often you charge and discharge your solar battery
• Your solar battery’s discharge rate

How much do solar panels save you on your energy bills?

Solar panels will save you up to 103% on your energy bills.

This savings level can be achieved if you choose an installer who will leave you with a well-sized solar panel system and solar battery, positioned properly on your roof.

And you could save even more, as shown by designs we’ve produced for households in Ipswich, Barnsley, and Tredegar in south-east Wales, which could all cut their electricity bills by well over 100%.

All of these designs are oversized, meaning they generate significantly more electricity per year than the households typically consume – in this case around double.

This allows these households to both cut the amount of electricity they buy from the grid, and make an overall profit by selling their excess electricity through Octopus Flux, a smart export tariff.

Of course, it’s also possible to reduce your electricity bills by less than average. Designs we made for homes in Birmingham, London, and Suffolk all would have decreased the occupants’ electricity bills by 65% to 69%.

This still represents a large reduction, and only doesn’t reach the average savings level because these are relatively small systems, placed in parts of the country that aren’t the sunniest.

This means they wouldn’t be able to export much excess solar electricity to the grid, which would affect their savings.

However, these three designs would all still break even after less than nine years, and save their owners more than £30,000 after 25 years – so even below-average systems are worth it.

If you would like to see the savings you could get from a solar & battery system, answer a few quick questions below and we’ll provide an estimate.

Will you still need to use the grid?

Around 37%* of your electricity will still come from the grid, on average.

If this seems strange – since the average solar panel owner reduces their electricity bills by up to 103% – it’s because a sizable proportion of your savings will come from exporting solar energy to the grid.

You’ll export the most electricity during the summer, when your solar panel system will usually generate more energy than your household can consume on any given day.

Even if you have a solar battery, your panels will eventually generate more electricity than it can store – which you can sell to the grid.

During winter on the other hand, your solar panels will supply considerably less electricity, which means you’ll rely on the grid for much more of your electricity.

See below for more information about how much you can earn from exporting excess electricity to the grid.

*This estimate is based on a household experiencing average UK irradiance with a 4.4kWp solar panel system and a 5.2kWh battery, using 3,500kWh of electricity each year and signed up to the Intelligent Octopus Flux export tariff.

Are energy bills likely to increase in the future?

If the past couple of decades are any indication, your energy bills could increase in the future, making solar panels a wise investment that may lead to even higher savings in the long run.

It’s difficult to predict future prices, but looking at past data helps shine some light. From 2000 to 2021, the cost of electricity rose by 5.5% per year on average, according to the Office for National Statistics (ONS).

Energy bills spiralled after Russia invaded Ukraine in 2022, sending shockwaves through an already troubled global energy market. They still haven’t returned to their previous levels, and they may never do.

Electricity price rises before 2022 were largely driven by inflation and grid upgrades, which are likely to continue being massive influences on your energy bills.

The UK is legally obliged to reach net zero emissions by 2050, which will require us to power energy-intensive processes like heating, lighting, and transport with green electricity – but that means we’ll need more than twice as much electricity as we use now.

The cost of developing the UK’s grid infrastructure will be passed onto consumers, meaning your energy bills may keep rising well into the foreseeable future.

How much can you earn from solar export tariffs?

The average solar panel system owner will earn around £350 per year* with Intelligent Octopus Flux.

Naturally, results will vary depending on a number of factors, including how large a solar panel system and battery you have, and where in the country your installation is located.

The average system exports 40% of the solar electricity it generates, as there are plenty of days throughout the year when it produces more than you can use, even with a battery.

If you’re signed up to a time of use export tariff like Octopus Flux, your battery will also fill up on grid electricity during off-peak periods, then send this electricity back to the grid when an on-peak time rolls around.

*This estimate is based on a household experiencing average UK irradiance with a 4.4kWp solar panel system and a 5.2kWh battery, using 3,500kWh of electricity each year and signed up to the Intelligent Octopus Flux export tariff

What’s the best solar export tariff?

The best solar export tariff is Intelligent Octopus Flux, in most cases.

On average, this tariff pays solar panel customers 30.31p for every kWh (kilowatt-hour) they export between 4pm and 7pm – well above the current cost of electricity, which is 24.5p per kWh, as of May 2024.

And the rest of the time, you’ll receive 22.7p per kWh on average, which is still extremely generous compared to all other export tariffs.

If you have an electric vehicle or heat pump though, it may benefit you more to use Intelligent Octopus Go or Cosy Octopus instead.

For more information, read our guide to the best export tariffs.

How much CO2 do solar panels save?

A solar panel system saves 1.1 tonnes of CO2 per year, on average.

This is more than a return flight from London to New York City, according to The Guardian.

In fact, over your solar panel system’s lifespan – which will likely be at least 25 years – you’ll save enough CO2 to cancel out the emissions produced by 27 return trips from the UK’s capital to the Big Apple.

And the bigger your system, the more CO2 you can save.

What are the other benefits of solar panels?

As well as saving you money and shrinking your carbon footprint, solar panels also offer a host of other benefits.

Firstly, solar panels can increase the value of your home by 3%, according to Rightmove’s 2023 study of 300,000 properties – which translates to around £8,600 added onto the price of the average house.

Looking forward, solar electricity is a great way to power green technology like heat pumps and electric vehicle chargers, which can potentially save you money and cut your emissions even further.

As well as fuelling the future, your solar panels will also soften the impact of any energy price rises in the years to come, as you’ll generate a large proportion of your own electricity.

And if you buy a solar battery with a gateway feature, you can protect yourself from power cuts by easily switching from grid power to solar electricity if the lights go down.

Are there other ways to generate green energy at home?

There are a few ways in which you can generate green energy at home, either instead of solar panels or – ideally – alongside them.

Wind turbines in particular work best in conjunction with solar panels, as they generate the most electricity during winter, when the wind is blowing and daylight hours are more limited.

A 6 kW pole-mounted wind turbine costs around £35,000, according to the Energy Saving Trust, and can cut your electricity bills by £510 per year – and smaller, cheaper versions are available.

If you happen to have a flowing body of water near your home, you could also use hydropower to produce energy, by installing a turbine to power a generator with the kinetic energy created by the water’s movement.

You’ll need planning permission for any hydropower project, no matter how small, but it could generate green energy for you all year round, with no interruption and very little variation.

You can also use anaerobic digestion, which is where you throw your food and animal waste into a sealed, oxygen-free container called an anaerobic digester that breaks down organic matter into biogas, which you can use to heat or power your home.

You’ll also be left with a nutrient-rich fertiliser that you can sell or use in your garden.

And just like with your excess solar electricity, any energy you generate with wind turbines, hydropower, or anaerobic digestion can be sold to the grid if you’ve signed up to a smart export tariff.

However, none of these alternate methods are particularly easy, which is why for the great majority of homes, solar panels are the best way to generate green electricity.

You can also heat a home with solar thermal panels, but technically that’s just a different use of solar energy.

Summary

Solar panels are the best, most cost-effective way to generate green energy that you can use to cut your electricity bills.

On average, they come with a break-even point of seven years, hundreds of pounds in annual savings, and a 3% boost to your home’s value.

And with energy prices staying high even as the UK moves towards a greener, more electricity-heavy future, they can soften the impact of any price rises.

If you’re interested in how much you could save with a solar & battery system, click the button below, enter a few details, and we’ll generate a quick estimate.

Is solar worth it?: FAQs