Solar panel power output explained: How much energy does a solar panel produce?

When thinking about switching to solar energy, one of the first things you’ll want to understand is how much power your solar panels can produce. This is important because knowing your solar panel output helps you figure out how much money you can save on your energy bills and how long it will take to recoup the costs of installation, known as the payback period.

Not only that, but the amount of energy your panels generate also determines the size and type of solar panel system that’s right for your home. By accurately calculating the expected output of your solar PV system, you can ensure that you’re getting the most value and efficiency from your solar investment.

On this page, you’ll learn:

• What solar panel output is and how it’s measured.
• How much energy different solar panel systems can produce based on your household size.
• How to calculate solar panel output for both daily and monthly energy needs.
• Why solar panel output changes between summer and winter in the UK.
• What to do if your system produces more energy than you use.

We’ve got a lot to cover, so without further ado, let’s get started!

Real-life examples of solar energy production vs household energy demands

The estimates above are based on average household energy consumption in the UK, following Ofgem’s stats and typical roof space requirements. But remember, these are just estimates. Solar panel output can vary based on your unique situation.

How much electricity your solar panel system can produce depends on a few key factors:

• The efficiency of the solar panels you choose. Higher efficiency panels will naturally produce more energy.
• Your location in the UK. Homes in areas with more direct sunlight will see greater solar panel output. Areas with fewer sunlight hours may need more panels to generate the same amount of energy.
• Your household’s energy consumption. How much power your home uses will determine how much energy your solar system needs to produce to meet your needs.

Solar isn’t one-size-fits-all, but with the right setup, it can make a significant difference in your energy independence. That’s why when you take these factors into account, you’ll certainly get a much clearer picture of how much solar power your system will produce.

What is solar panel output?

Put simply, solar panel output is all about how much electricity your solar panels can produce. For UK homeowners, understanding this is particularly important because it helps you figure out how much energy your system will generate.

Additionally, understanding your solar panel output will help you figure out how much you’ll save on your energy bills. The more electricity your solar panels produce, the less you’ll need to rely on the grid, giving you more energy independence and reducing your carbon footprint. It’s a win-win for both your wallet and the environment.

DID YOU KNOW… Winter makes solar panel output drop due to shorter days, lower sun angles, cloud cover, and occasional snow, though light snow often melts or slides off. However, colder temperatures enhance efficiency, increasing power output by up to 0.5% per degree below 25°C.

How is solar panel output measured?

Solar panel output is measured in watts (W). Basically, the higher the wattage, the more electricity your panel can generate when the conditions are just right. But it’s not all about the solar panel wattage. Things like where you live, the angle of your roof, and how much direct sunlight your home gets will also affect how much power your solar panels produce. So, while higher wattage helps, there are a few other pieces to the puzzle when it comes to maximising your energy.

For example, if a solar panel has a power output of 350 watts, that means, in ideal conditions, it could generate 350 watts of electricity every hour. Think of it like this: the more watts, the more electricity your panels can produce when the sun is shining at its brightest.

Watts vs Kilowatt Hours (kWh)

It’s also good to know the difference between watts and kilowatt hours (kWh).

• Watts measure how much power your solar panels can generate, while
• kWh tells you how much electricity your home actually uses. You’ll see kWh on your electricity bill.

So, for example, if your household uses 2,700 kWh a year, that’s the total amount of energy you’ve consumed over the course of the year.

How much power does a solar panel produce?

Knowing how much power your solar panels can produce is truly important when planning your solar energy system. It really all comes down to a few things. These include how much energy your household uses, how many panels you install, and how efficient those panels are at generating electricity.

Here’s a quick breakdown of how much energy different households in the UK usually use and how much solar power their panels can produce:

From the above, we gather that a household with 1-2 people typically uses around 1800 kWh of electricity each year, which means they’d need about 6 solar panels to generate around 1590 kWh. On the other hand, a family of 4-5 people who use about 4100 kWh annually would need closer to 14 panels to meet their energy needs.

In the UK, a typical 350W solar panel generates around 264.5 kWh of electricity per year. So, for example, if you live in a 3-bedroom house and use about 2700 kWh annually, you’d need roughly 10 panels to cover that, with each one producing around 264.5 kWh. This gives you a good idea of how many solar panels you might need based on your household’s energy usage.

When UK homeowners start thinking about switching to solar power, one of the first questions they ask is, “How many solar panels do I need?“ It’s a big question because the number of panels you install will affect the size of your solar system, how much it costs, and how much you can save on your electricity bills.

The number of solar panels you’ll need depends on a few key things, like:

• How much electricity your household uses.
• The efficiency of the panels you choose (for example, monocrystalline panels are more efficient and can generate more electricity in less space).
• How much sunlight your home gets throughout the year.
• How much roof space you have for installing the panels.

By looking at these factors, you can get a clearer idea of how much energy your solar panel system will produce and how many panels you’ll need.

How to calculate the average panel output per day and month

When you’re planning your solar panel system, it’s helpful to know not just the yearly energy output but also how much electricity your panels produce each month and day. This gives you a clearer picture of how much power your solar panels are generating over time, so you can see if they’re keeping up with your household’s energy needs.

Let’s break it down and see how this works for different household sizes:

Now that we’ve looked at the breakdown, let’s talk about how to figure out these values for yourself:

• Daily Energy Output: To figure out how much energy your solar panels produce each day, just divide the yearly energy output by the number of days in a year (365). For example, if your system generates 2645 kWh in a year (for a 3-person household), you divide that by 365, which gives you an average daily output of 7.25 kWh.
• Monthly Energy Output: For monthly energy output, it’s just as easy—divide the annual production by 12. Using the same example of 2645 kWh per year, you’d get a monthly output of about 220.4 kWh.

But what if you want to figure this out without using Ofgem’s data or for different situations?

No problem!

Here’s an easy formula you can use!

DIY Formula to calculate solar panel output per day:

Here’s how you can figure out how much electricity a solar panel produces each day, step-by-step:

Step 1: Let’s say your solar panel is 2 square metres in size.
To start, you multiply the size by 1,000 (since about 1,000 watts of sunlight hits each square metre):
2m² × 1,000 = 2,000W.

Step 2: Now, if the panel has an efficiency of 18%, that means it converts 18% of the sunlight into electricity.
So, 2,000W × 0.18 = 360W.

Step 3: Next, if your area gets about 5 hours of sunlight per day, you multiply:
360W × 5 hours = 1,800Wh (which is 1.8 kWh).

Step 4: Finally, divide by 1,000 to convert it to kilowatt hours:
1,800Wh ÷ 1,000 = 1.8 kWh per day.

So, a 2-square-metre solar panel with 18% efficiency and 5 hours of sunlight would produce about 1.8 kWh of electricity each day.

Solar panel output winter vs summer in the UK

Solar panels work all year round, even during the winter months.

A lot of people think that cold weather affects a solar panel’s performance, but that’s not true. Solar panels depend on sunlight and daylight to operate, not heat or cold temperatures. In fact, solar panels actually operate more efficiently in colder temperatures.

The big difference between winter and summer is the amount of daylight. In the winter, the UK has shorter days and less sunlight, which means solar panel output naturally drops.

In fact, you can expect a reduction in performance of anywhere from 25% to 50% during the winter months compared to the summer. This is simply because there are fewer hours of sunlight available.

While energy production is lower in winter, solar panels are designed to handle the UK’s weather conditions, including snow, storms, and hail. So, even during harsh weather, your panels can keep producing energy—just at a lower rate than in the sunny summer months.

Even though the energy output is reduced in winter, solar panels remain effective as they can still harness daylight and continue generating electricity. The better your panel efficiency and the more panels you have, the more energy you can capture, even during the darker winter days.

Excess energy: What happens if your solar PV system produces more electricity than you need?

It’s great when your solar panels are producing lots of electricity, but what happens if they generate more power than your home needs? Luckily, you have a couple of options to make the most of this excess energy.

You can either store the extra energy using a battery storage system or export it back to the grid through a government-backed scheme called the Smart Export Guarantee (SEG).

Net metering and grid connection options

If your solar panel system produces more electricity than you use, one incredible option is to send that extra energy back to the national grid. In the UK, the Smart Export Guarantee (SEG) lets you do just that, and it pays you for every kilowatt-hour (kWh) of energy your solar panels generate but don’t use.

Right now, SEG offers around £0.12 per kWh, but this rate can vary depending on your energy provider, so it’s worth shopping around for the best deal. These SEG payments can give you an extra source of income, making your solar investment even more valuable.

Another option is net metering, where you can sell any excess energy back to the grid to offset your energy bills. This means you’ll get credited for the electricity your solar panels generate but don’t use, reducing the amount of energy you need to buy from your provider.

Solar battery storage solutions for excess energy

Another way to manage your excess electricity is by adding a solar battery. This lets you store the extra energy your solar panels produce during the day so you can use it later, such as in the evenings or on cloudy days when the sun isn’t out.

While solar batteries are a great way to increase your energy independence, they can be pricey, and they’re not always the best option for everyone. Sometimes the cost of a battery can outweigh the benefits, especially if your energy usage is low or if you’re working with a tighter budget.

Before deciding if a solar battery is right for you, it’s important to think about your household’s energy usage and whether the potential savings will be worth the upfront costs. In some cases, it might be more cost-effective to rely on the grid for balancing your energy needs.

Solar panel system size & configuration example

When you’re designing a solar panel system, there are a few key things to think about. This includes things like where you live, the size and direction of your roof, and the type of solar panels you choose. All of these affect how much electricity your system will produce.

On average, a solar panel system can cover around 50% of your yearly energy needs. But if you add a solar battery, you can boost that number by storing and using more of the energy your system generates, even when the sun isn’t shining.

Let’s take a look at a few practical examples based on common UK household sizes:

We can see here that a typical household with 1-2 people using around 1800 kWh of electricity per year would need a 2 kWp system with about 6 solar panels to produce roughly 1590 kWh annually. On the other hand, a larger household with 4-5 people using 4100 kWh each year would need a 5 kWp system with 14 panels to produce around 3700 kWh per year.

Of course, the actual performance of your system depends on specific factors like the size and direction of your roof, and the efficiency of the solar panels you choose.

Adding components like a solar battery can also take your system’s efficiency to the next level. By storing the extra energy your panels produce during the day, you can use that energy when the sun isn’t shining. This increases your self-consumption, which means you’ll rely less on electricity from the grid.

Here’s a simple breakdown of the costs:

• Energy Price: £0.38 per kWh*
• SEG Payment: £0.12 per kWh exported
• Energy User Type: Home all day

*Currently, most UK households pay around £0.38 per kWh for electricity. With energy prices on the rise, generating your own electricity with solar panels can lead to significant savings. By using your own solar power instead of buying electricity from the grid, you can cut down your energy bills considerably.

Solar panel system comparison: With or without battery?

One big decision when installing a solar panel system is whether to add a solar battery. A battery lets you store the extra energy your solar panels generate during the day, so you can use it later—like at night or on cloudy days when the panels aren’t producing as much electricity.

Below, you’ll see a comparison of a 3.5 kW solar panel system with and without a battery. Adding a battery can boost your self-consumption by letting you use more of the energy you produce, meaning you’ll rely less on the grid. You’ll also notice that having a battery slightly shortens the payback period, making it a solid investment in the long run.

(Note: The figures and examples provided in the following table are for illustration purposes only. Actual system performance may vary depending on factors such as location, weather conditions, panel orientation, and installation quality. Always consult with a professional to assess your specific energy needs and system capabilities).

From the above, you can really see that a 3.5 kW solar panel system without a battery can cover around 37% of your energy needs with the remaining 63% of energy being sent back to the grid. However, if you add a solar battery, your self-consumption jumps to 86%, meaning you can use a lot more of the electricity your system generates, and you’ll need to buy much less from the grid. This leads to bigger savings of around £1,117.22 per year with a battery compared to £702.97 without one.

The payback period for both systems is about the same, with both breaking even at around 9.9 years. But adding a battery gives you greater long-term savings and more energy independence, especially if you use a lot of energy during times when the panels aren’t generating electricity (like in the evenings).

With energy prices currently around £0.38 per kWh, self-generated solar power is a great way to cut costs. The less energy you need to buy from the grid, the more you save.

This comparison really shows the impact of adding a battery to your system, making solar power even more cost-effective and energy-efficient. Whether or not a battery is the right choice for you will depend on your energy usage and budget, but it’s clear that a solar system with a battery offers significant benefits over time.

FAQ

What is the output of a solar panel?

Solar panel output is simply how much electricity a panel can generate, and it’s measured in watts (W) or kilowatts (kW). For example, a typical solar panel might have an output of 350 watts (W), which means that under ideal conditions, it can produce 350 watts of electricity per hour. However, the actual power output depends on a few factors, like the efficiency of the solar panel, how much sunlight it gets, and where your home is located.

How many kW is 10 solar panels?

The total kilowatt output of 10 solar panels depends on the wattage of each one. For example, if each panel is 350 watts, then 10 panels would give you a combined output of 3.5 kW (since 10 panels × 350 watts = 3,500 watts or 3.5 kW). This size system is pretty typical for households with moderate electricity needs.

How many kW do solar panels produce?

The number of kilowatts (kW) a solar panel produces depends on its size and efficiency. Most residential solar panels today are between 250W and 400W. For example, a 350W panel can generate 0.35 kW of electricity per hour under ideal conditions. To figure out the total output of your solar system, you just multiply the number of panels by the output of each one.

How many kWh does a 350w solar panel produce?

A 350W solar panel can generate around 350 watts per hour under ideal conditions. Over the course of a year, that adds up to about 264.5 kWh of electricity. This is based on typical sunlight hours in the UK, which average about 4 hours of sunlight per day.

Final thoughts

Switching to solar energy is a great way to take control of your electricity usage, cut down on energy bills, and shrink your carbon footprint. Now that you know how much power your solar panels produce, how many panels you’ll need, and how to get the most out of your system with or without a battery, you’re ready to make informed choices.

Whether it’s understanding how solar panel output changes between winter and summer or learning how to manage excess energy by sending it back to the grid or storing it in a battery, it’s clear that solar power brings huge long-term benefits. The best part? Solar panels keep working for decades, providing savings and sustainability for years to come.

No matter the size of your household or your energy needs, solar energy is a great way to create a cleaner, more efficient future. And with rising energy prices, there’s never been a better time to make the switch.

Next steps

Now that you know how solar panels work and how much you could save, it’s time to take the next step in your solar journey!

Contact our solar experts today to get a personalised recommendation for the best solar panel system for your home. We’ll work with you to design a system that fits your energy needs, budget, and goals—whether you’re looking to add a solar battery for extra savings or stick with a simple solar panel setup.

You can also use our solar panel calculator to quickly estimate your system’s output and see how much you could save on your electricity bills. Our team is here to guide you through every step of the installation process.

Start your solar journey today and enjoy lower energy bills while reducing your carbon footprint. The future of clean energy is bright, and we’re excited to help you be part of it!

Why choose Soly for your solar panel needs?

At Soly, we make solar energy accessible and ensure your photovoltaic system lasts as long as possible, performing at its best. Here’s why we’re the ideal choice for your solar energy journey:

• Affordable financing: We understand that upfront costs can be a barrier to going solar. That’s why we offer convenient financing options, including a £500 deposit plan, where the remaining balance is due only after your system is installed and operational. This makes solar energy more affordable for UK residents. Soly also partners with Ideal4Finance, providing tailored, competitive financing with instant, personalised offers.
• Referral benefits: Soly offers the best referral scheme in the solar market. As a Soly customer, you can earn £300 for each friend you refer who installs a system with Soly—with no limits! This can significantly help reduce your payback period. For example, one of our customers, Martyn, managed to reduce his payback period by nearly a year by referring just three friends.
• High-quality panels: We use only the best solar panels, offering monocrystalline solar panels from Jinko Solar. Known for their efficiency and durability, these monocrystalline solar panels can last for up to 40 years, ensuring you get the most out of your investment.
• Trusted reputation: Soly is proud to be highly rated on platforms like TrustPilot and Google and recognized as a certified Which? Trusted Trader. We’ve built a reputation for excellence, earning the trust of countless satisfied customers, with our commitment to quality evident in every installation.
• Accredited installers: We work exclusively with local installers nationwide who are accredited by HIES, TrustMark, and MCS, ensuring that your solar system is installed with the highest industry standards in mind. Proper installation plays a huge role in maximising the lifespan of your solar panels.
• Expertise you can trust: With over 10 years of experience in the solar industry, we know how to deliver the best solar solutions tailored to your needs. Our team of experts will ensure your system is designed to last.
• Peace of mind: We provide up to 25-year guarantees for our solar panels and 15-year guarantees for our solar batteries. This means you can have peace of mind knowing your investment is protected for decades to come.

Reach out to our solar experts today to discover how Soly can help you transition to clean, renewable energy with the best products and financing options.