Guide to Solar Panel Sizes & Dimensions in the UK

Do you want to install a solar system on your roof? Don't know what solar panel size would be suitable to meet your energy needs? Looking forward to exploring common types of panels and their dimensions in the UK? This guide has it all.

Don't invest in solar panels until you read the discussion below carefully. It presents various PV panel sizes currently available on the UK market. It also lists the potential factors that affect the panel's output. Furthermore, you will learn to choose the right size solar panel to meet your energy requirements.

Solar Panels Sizes & Dimensions: An Overview

Though solar panel sizes and dimensions sound similar, they are different from each other. Every owner must know this difference, as it clarifies a range of queries, such as “what is the cost of PV panels,” “how many panels do you need,” and “how big a panel is in the UK.” Let's now understand how panel size and dimensions are different quantities.

• Size: It tells the amount of electricity or power a solar panel can produce. The residential panel sizes range between 250 watts and 450 watts. You can simply multiply the panel's amperage by its voltage to calculate its size.
• Dimensions: They tell how long, wide, and thick a solar panel is. Each panel is made up of several cells. The dimensions of each cell are usually around 6.2 x 3.28 x 0.13 feet, whereas the dimensions of each solar panel are typically between 17.22 and 21.52 sq. feet.

Different manufacturers offer different types and sizes of PV panels in the UK. Different solutions may need panels with different sizes and dimensions. It shows you have more flexibility in selecting the right solar panel for your home setup. If you have to pick one parameter while buying panels, choose the size over dimensions (as it tells the amount of power the panel will generate).

Common Types of Solar Panels and Their Sizes

The solar panel sizes vary depending on their types, as explained below.

1. Monocrystalline Panels

They are known for providing the highest solar power output and are listed among the most efficient cells. These black-coloured panels are prepared with single silicon crystals. You can find monocrystalline panels in rectangular or square shapes on the market. Their sizes range between 60 and 120 cells. 60-cell and 72-cell monocrystalline panels are commonly used for residential applications.

2. Polycrystalline panels

The efficiency of these panels is lower than their monocrystalline alternatives. In addition, they are less expensive. Polycrystalline panels come in a speckled blue color and are manufactured with multiple silicon crystals. If you have a limited roof space, these panels should be your top choice. They are available in 36-72 cell sizes, out of which 60-cell and 72-cell are commonly used.

3. Bifacial panels

As the name depicts, these panels can absorb sunlight from both front and back surfaces. Bifacial panels capture direct light from their top cells and the reflected light from the bottom cells. They are more efficient than panels that capture sunlight from a single side. They are available in 60-144 sizes. It shows that they are bigger than monocrystalline panels. 72-cell and 144-cell panels are commonly used. The building block of these panels is a crystalline silicon cell.

4. Thin Film

They are the most expensive panels on the UK market. Plus, they offer a lower power output. A thin layer of photovoltaic material is used to make these solar panels. You can mount thin film panels on different roof styles, as they are available in different shapes and sizes. Remember, these panels are less durable and less efficient than monocrystalline and polycrystalline panels. Their size varies between a few square centimetres and several square meters.

Solar Panel Size Chart in the UK

Do you want to compare solar panel sizes of different types (explained above) to make an informed decision? The table below will lend you a helping hand.

How Do You Calculate Solar Power?

If you want to calculate solar power in the UK, you should consider two potential factors: output rating and peak sunlight hours. They both contribute to estimating solar power.

Solar panels are usually rated in watts, e.g., 250W, 350W, and 400W. A 3-6 kW solar system is enough to power a standard home in the UK. The average UK-based home receives peak sunlight for 3-4 hours per day. However, peak sunlight hours may vary depending on your location. Northern areas receive less sunlight than southern regions.

Let's now look at the formula to calculate solar power in kWh using the system size and peak sunlight hours.

Solar Power Output (kWh) = System Size (kW) x Peak Sunlight Hours (h)

For example, if you have installed a 5 kW solar system on your roof and your home receives peak sunlight for 4 hours, the energy output will be 20 kWh per day (5x4). Multiply the answer by 365 to calculate your annual energy output (20 x 365 = 7,300 kWh).

Factors that Affect Solar Panel Output

Apart from the panel's size, some other factors also significantly affect its output. Let's look at them one by one.

• Energy Requirements: Your power needs directly affect the output parameters. Determining your daily, monthly, and yearly energy requirements helps you determine the right size system.
• Weather Conditions: Mild weather consumes less power than hot or cold climates. The reason behind this fact is that energy consumption fluctuates with cooling and heating requirements.
• Structure: PV technology, composition, and the dimensions of solar panels also affect their outputs.
• Irradiance: It comes into play as Earth has different places with varying peak sunlight hours. As a result, the sum of solar energy varies, too.
• Average Size: It covers solar panel sizes, the load your roof can bear, and the space available on your roof.

Decide What Solar Panel Size You Need in 4 Easy Steps

A quick guide to deciding on the solar panel size is as follows.

Step 1: Calculate Your Energy Consumption

The best way to calculate your power needs is to look at your electricity bills. They will help you find both monthly and yearly energy consumption in kWh. For example, if your home uses 4,000 kWh per year, you will need a solar system that can produce at least this much power.

Step 2: Determine the Available Space on Your Roof

Calculate the area on the roof to find how many panels you can easily install on it. A standard 350-watt solar panel occupies around 1.7 square meters.

Step 3: Find the Number of Panels Required

Suppose you need a 4kW solar system for your home. In that case, 10-12 panels will be required to power appliances. They will need a space of around 15 to 20 square meters. You can divide the total space available by the number of panels required to calculate the size of one panel.

Step 4: Consult a Professional

Once you have an idea of the solar panel size you need to set up a system on your roof, it is always recommended to cross-check it with a solar professional. It will eliminate any confusion or error that occurs during your calculation.

Final Thoughts

Solar panel sizes and wattage are correlated,-as the size is usually measured in watts or kilowatts. As far as solar panel dimensions are concerned, they tell how big a panel is. It shows that size and dimensions are two different terms and are not interchangeable. For domestic installations, solar panel sizes in the UK range between 250 and 450 watts.

Factors like energy requirements, irradiance, and atmospheric conditions have a huge impact on the solar panel output. If you want to determine the right size solar panel to install a home PV system, the discussion above has presented a step-by-step guide. Give it a read. If you need long-lasting solar panels in the UK at competitive prices, explore the collection at Renogy.

Solar Panel Sizes FAQs

1. What is the average size of a solar panel in the UK?

Answer: The average size of a solar panel in the UK for residential use is around 1.7 meters long by 1 meter wide, with a thickness of 3-5 cm. In terms of power output, most panels range from 350W to 450W, making them suitable for typical UK homes. The exact size depends on the manufacturer and your energy needs, so consulting a local installer is recommended.

2. How many solar panels do I need for my home in the UK?

Answer: The number of solar panels you need depends on your energy usage and roof space. For an average UK household using 2,700 kWh per year, a 4kW system with 10-12 panels (350W-450W each) is typical, requiring about 20-24 square meters of roof space. Assess your annual electricity bill and roof dimensions to get a precise estimate.

3. What size solar panel system is best for a 3-bedroom house in the UK?

Answer: For a 3-bedroom house in the UK, a 4kW to 5kW solar panel system is usually ideal, consisting of 10-14 panels (350W-450W each). This covers around 3,400-4,250 kWh annually, meeting most of the energy needs for a family of 3-4. South-facing roofs maximize efficiency, but east or west orientations work too.

4. How do solar panel sizes impact installation costs in the UK?

Answer: Solar panel sizes affect installation costs in the UK based on the number of panels and system capacity. Smaller panels (e.g., 350W) may require more units for a 4kW system, increasing labour costs, while larger panels (e.g., 450W) reduce the number needed, potentially lowering installation time. On average, a 4kW system costs £6,000-£8,000, including panels and fitting—larger, efficient panels might save money long-term despite higher upfront costs. Get quotes from UK installers to compare.