Solar Panel Output: How Much Electricity Do They Produce? Written by Beth Howell Reviewed by Charlie Clissitt Updated on 24 February 2023 ✔ A solar panel's power output is measured in kilowatts (kW)✔ A three-bedroom house will typically need a 3.5 kilowatts peak (kWp) system✔ Solar panels cover roughly 50% of household electricity needsInvesting in solar panels costs a pretty penny, so it can be daunting if you’re not familiar with the lingo – and ‘solar panel output’ is a daunting level of jargon. But we’re here to make it easier for you.We’ve compiled all the need-to-know things when it comes to making sure you have the right amount of power flowing out of your panels.Already familiar with all things solar? Dive in and get yourself a quote for a new solar panel system with our simple comparison tool.Once you’ve filled in a few details, our suppliers will be in touch with quotes for you to compare. You’ll find the right deal in no time, allowing you to make vital savings during this cost of living crisis. Where do you want to install solar panels? Roof Ground Both Other / not sure Get started Loading What's on this page? 01 What is a solar panel’s power output? 02 How much power can a solar panel system generate for your property? 03 Solar panel output: winter vs summer in the UK 04 High output solar panels 05 How to monitor solar panel output 06 What affects how much electricity a solar panel can generate? 07 How will you know how much electricity your solar panels generate? 08 FAQs What is a solar panel’s typical power output?Let’s start off with the basics – a solar panel's output is expressed in watts (W).The higher the wattage of a solar panel, the more electricity it can produce under the same conditions. These conditions will depend on where you live, the angle of the roof, and the direction your home faces.A typical solar panel is rated 350 W, which is a measurement of power. A solar panel with this level of power will produce an average of 265 kilowatt hours (kWh) of electricity per year in the UK. For context, a kilowatt hour is used to measure the amount of energy someone is using; you’ll often find it on your energy bills.If a homeowner’s solar panel system included 12 of these panels, it would produce an average of 3,180 kWh of electricity per year.Average solar panel output per dayThe average 350 W solar panel will generate about 0.72 kWh of electricity per day. But this is only one panel. The average three-bedroom property needs a system with at least 10 panels to cover its electricity needs (although half of this electricity won’t actually get used – but more on that later), meaning the whole solar panel system would produce 7.2 kWh of electricity per day.Solar panel output per m²The output per m² of an average 350 W solar panel in the UK is 132.5 kWh. How much power can a solar panel system generate for your property?If you get a decent installer who can accurately assess how much electricity your solar panel system will need to produce, it should generate roughly as much electricity as your property uses.However, you’ll only actually end up using about 50% of this electricity, unless you have a battery to store electricity during the evenings and times when you’re out of the house – in this case, you’ll end up using about 80% of the electricity.Check out the table below to see how much electricity different sized solar panel systems can produce for various properties. Or, you can read about 5 kW solar panel systems specifically and find out if this size system is right for your property.Use our solar panel output calculator to work out what number and peak power output of panels you need.Property sizeAnnual electricity usage (kWh)Solar PV system size (kW)Number of panelsAnnual electricity output (kWh)1-2 bedrooms1,8002.161,5873 bedrooms2,7003.5102,6454+ bedrooms4,1004.9143,703Why do solar panels only cover 50% of your electricity needs?One of the main drawbacks of solar panels is that you can only consume the electricity they produce in real time – whilst you’re in the house, during the daytime.Solar panels won’t produce any electricity during the evenings, because there’s no sunlight for them to absorb. On top of this, people aren't typically at home all day to use the electricity generated by solar panels. These are two key reasons why solar panels can only really cover 50% of homeowners’ electricity needs.There is always the option to pair a solar panel system with a storage battery, which allows homeowners to store any surplus energy their panels produce.But even then, the homeowner will only be able to use up to 80% of their solar-generated electricity, as battery technology still has limited capacity levels. The remaining 20% ends up going back to the grid. Where do you want to install solar panels? Roof Ground Both Other / not sure Get started Want to get a better idea of what it’s like to own a set of solar panels? Check out our case study with Shirley Ward – a 73-year-old retired office worker, based in North Yorkshire. Shirley has a 2.4 kW solar array and a Solax battery, and managed to break even on the system in 10 years. Despite electricity prices increasing around the world, Shirley’s panels have brought her energy bills down to £15 a month, instead of £50. Check out the full interview with Shirley to learn more about solar panels. Solar panel output: winter vs summer in the UKAlthough solar panels work all year round, their output levels fluctuate throughout the seasons. This boils down to the changes in the amount of sunlight exposure the panels get each month.As you might have guessed, solar panel output reduces during the winter in the UK – by 83%, on average.This is because the days are shorter in the winter months, meaning panels aren’t exposed to as much sunlight as they are in the summer. The sun is also lower in the sky during the winter, which can impact sunlight exposure, and it's usually cloudier. Get free solar panel quotes Answer a few quick questions, and our trusted installers will send you bespoke solar panel quotes – for free. Compare now High output solar panelsIf you really want to get the most out of your solar panels, you might want to look into products with a high output rating.To help you get a headstart, we’ve listed the most powerful panels on the market in the table below.CompanySolar panel modelPower/outputSeraphimSRP-670-BMC-BG670 WSeraphimS5 Series SRP-670-BMC-HV670 WAIKOAIKO N-Type ABC White Hole Series (72 Cells)620 WAIKOAIKO N-Type ABC Black Hole Series (72 Cells)615 WJinkoTiger Neo N-type 72HL4-(V)585 WLongiHi-MO 7 (LR5-72HGD-580M)580 WJA SolarJAM72D40580 WJinkoTiger Neo N-type 72HL4575 WSharpNB-JD570570 WTongwei SolarSilver Frame Shingled Module560 WThese figures were sourced from our research of the best solar panels on the market. Want to take a look at the findings? Head to our Guide to the Best Solar Panels in the UK. How to monitor solar panel outputIt’s important to monitor how your solar panels are performing on a regular basis, to make sure they're generating the expected amount of power. If your solar panels' power output is particularly low, it could be a sign of a problem.One way you can do this is by checking the solar panel meter that will be placed in an accessible location within your home. This meter will record the amount of electricity being produced by your solar panels.But to make things even easier, some solar brands have rolled out online monitoring tools, which means you’ll be able to see how much power your solar panels are generating with the click of a button on your computer or phone.There are also a number of apps that solar panel owners can download that can give you an insight into how your system is running. Some of the most popular apps include:SolarEdge MonitoringEnergy Monitoring & Analysis App (EMA)Enphase Enlighten AppSMA Sunny Portal App What affects how much electricity a solar panel can generate?If conditions aren’t ideal, your solar panels’ efficiency will take a hit, meaning they won’t be able to work at their maximum power output.There are several factors that can impact how much electricity a solar panel is able to generate. These include:Direction and angle of your roofA solar panel works at its best when installed on a south-facing roof at a 35-degree angle. However, solar panels can still produce a decent amount of power on an east-facing or west-facing roof, and at an angle anywhere between 10 and 60 degrees.Most houses will fit this description – which is fortunate, since you can't change the angle of your roof without a lengthy, difficult process that involves a complicated frame system and new planning permission.You can learn more on our page: What’s The Best Angle and Direction for Solar Panels?ShadeMake sure your solar panels are installed out of the shade, in direct sunlight. If just a small amount of shade covers a solar panel, it can significantly reduce how much electricity it’s able to generate.Time of the yearA solar panel will produce more power in the summer months when the days are longer and there are more sunshine hours.If it gets too hot, however, solar panels can overheat; if their temperature goes over 25°C, they'll generate slightly less power.DirtIf a solar panel is covered in debris, its power output will fall because sunlight will be stopped from hitting the panel. Thankfully, there are a few ways you can protect your solar panels from this.Make sure you regularly clean your solar panels in the evening with a hosepipe, as long as the jet of water can reach them.If your panels are seriously soiled, a professional clean may be worthwhile – and remember: although it rains a lot here in the UK, don’t rely on downpours to wash away the dirt.You can find out more on our helpful guide Reasons Solar Panels Lose Efficiency Over Time (And How to Slow It Down). How will you know how much electricity your solar panels generate?Your solar panels will come with a meter that will be placed in an accessible location within your home. This meter will record the amount of electricity being produced by your solar panels.Some solar brands are also rolling out online monitoring tools, which means you’ll be able to see how much power your solar panels are generating with the click of a button on your computer or phone.As solar panels require virtually no maintenance, it can be easy to forget about them once they're installed on your roof. We'd recommend checking them regularly, however, to ensure they're clean and in good condition.It's worth monitoring your meter frequently too, to make sure they're generating the expected amount of power. If your solar panels' power output is particularly low, it could be a sign of a problem.Finding an installerFeeling more clued up on solar panel output? Well then, perhaps now’s the time to make the switch to solar.After all, a majority of people want to go solar, according to our National Home Energy Survey.Plus, just like we’ve simplified solar in this article, we can make the comparison stage easier for you too!The only thing you need to do is put a few details in our easy-to-use comparison tool – then put your feet up and let us do the hard work. We’ll pass on your information to our suppliers, who’ll then be in touch shortly with free quotes for you to compare. You’ll be reaping the solar-powered rewards in no time! FAQs Is it still worth installing solar panels in the UK? Yes, it’s definitely worth installing solar panels in the UK. Although homeowners in a three-bedroom house will typically need to spend about £7,860 for 10 panels, they'll save 70% on their electricity bills.The average homeowner can also break even on their solar panels after 15.1 years, according to our latest calculations.Is it even worth it in Scotland? As far north as you can go in the UK? Yes, it's even worth getting solar panels in Scotland.Want to learn more? Head to our page Are Solar Panels Worth It In The UK? Is it worth getting a battery with solar panels in the UK? This one’s tricky. On the one hand, if you don’t have a solar battery, you’ll most likely end up losing around 50% of the power your solar panels produce, with all the surplus energy going straight to the grid.On the other hand, solar batteries tend to cost around £4,500, which can be a barrier for many – you’ll also need to buy two of these throughout a typical solar panel’s lifetime. Typically, it’ll take homeowners 26.3 years to break even on a solar plus storage system.You can find out more about this on our page Are Solar Batteries Worth it in the UK? What happens to excess electricity from solar panels? There will be times when your solar panels generate more electricity than you can use, such as when you’re out of the house and not using household appliances.In this case, the surplus electricity is exported to the grid. But you can still benefit from this by applying for the Smart Export Guarantee (SEG) – a scheme that obliges large energy suppliers in the UK to pay households for the renewable energy they export to the National Grid.ScottishPower currently offers the best SEG rate that anyone can access, paying 12p for every kWh of electricity a household sends to the grid from their panels.As an alternative, some people prefer to use a solar diverter to deal with excess energy – a device used to direct excess electricity generated by the solar panels towards a specific load or appliance. Can I run my house on solar power only? It’s definitely possible to run a house on solar power alone, but that might not be a realistic goal for many people at the moment.Going completely off-grid requires a lot of financial investment – not only will you need to fork out at least a few thousand pounds for the solar panel system, but you’ll probably need to invest in more than one battery to store enough electricity to cover all your electricity needs.Remember, solar panel output drops by roughly 50% during the winter in the UK, so you’ll need to store enough solar energy throughout the year to supplement this. Written by: Beth Howell Content Manager Beth has been writing about green tech, the environment, and climate change for over three years now – with her work being featured in publications such as The BBC, Forbes, The Express, Greenpeace, and in multiple academic journals. Whether you're after a new set of solar panels, energy-saving tips, or advice on how to reduce your carbon footprint, she's got you covered. Reviewed by: Charlie Clissitt Editor Charlie has been researching and writing about the home energy market for over five years, and he has been the editor of The Eco Experts since 2021. Charlie's thoughts on solar panels have seen him featured in various publications, including The Times, Ideal Home, and Grand Designs Magazine. Ever since he can remember, Charlie has worried about the planet, and he one day dreams of owning a solar power farm.