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How Many Solar Panels Do I Need for My House?

Published on:
8 September 2023

Switching to solar energy is an eco-friendly and cost-effective choice for powering your home in the United Kingdom. However, determining how many solar panels you need can be tricky, as it depends on several factors. In this blog post, we will explore the key considerations and provide guidance on calculating the correct number of solar panels for your home. 

How many solar panels will my home need? 

On average, a one-bedroom house needs six solar panels, a typical three-bedroom house requires 10 panels, and a five-bedroom house will usually need 14 panels. However, there are multiple factors which determine how many solar panels your home will need. These factors include: 

Your Energy Consumption -The first step in determining how many solar panels you need is to assess your household’s energy consumption. According to data from the Department for Business, Energy & Industrial Strategy (BEIS) in 2020, the average electricity consumption for a UK household was approximately 3,600 kWh per year. This figure can serve as a baseline to estimate your energy needs. 

Panel Efficiency and Sunlight – In the UK, the amount of sunlight varies throughout the year, affecting the efficiency of your solar panels. According to the Solar Trade Association, on average, solar panels in the UK have an efficiency rating of around 10-15%. This means that for every 1 kW of solar panels, you can expect to generate between 1,000 and 1,500 kWh of electricity annually. Learn more about which solar panels are the most efficient.  

Roof Orientation and Angle – The orientation and angle of your roof plays a crucial role in solar panel efficiency. To get the most out of your solar panels, they should ideally face south and have an angle of around 30-40 degrees. The UK Solar Trade Association suggests that south-facing roofs can maximise sunlight exposure. However, the positioning of solar panels can vary and still be effective, depending upon individual circumstances, for which we can provide further guidance.  

Available Roof Space – The size of your roof will also determine how many solar panels can be installed. To calculate the available roof space, you can measure the length and width of the area where you intend to install solar panels. Remember that shading from nearby trees or buildings can affect panel efficiency, so it’s essential to consider these factors. 

Panel Wattage – Solar panels have various wattage ratings, typically ranging from 250W to 400W per panel. However, increasingly efficient products are now being introduced on a regular basis. As a general guide, the higher the wattage, the more electricity a panel can generate. You can choose panel wattage based on your available roof space and energy needs. 

How many people live in your home – How many people living in your home will affect how much electricity you use and therefore how many solar panels you need. For example, a large four-bedroom home with only two full-time occupants, might only need six to 10 solar panels, instead of 14, as less people will be using electricity. 

Here’s a guide how many solar panels you need per person: 

  • One to two people – 6 solar panels 
  • Two to three people – 10 solar panels 
  • Four to five people – 14 solar panels 
  • Over five people – 16+ solar panels 

Calculating the Number of Panels – Now that we have gathered the necessary information let’s calculate the number of solar panels you need for your UK home: 

  1. Determine your annual energy consumption (e.g., 3,600 kWh). 
  1. Calculate the total energy production of your solar panels. For example, if you choose 300W panels, divide 3,600 kWh by 0.3 (i.e., 300W converted to kW) to get 12 kW. 
  1. Considering the efficiency and available sunlight (let’s use 15% efficiency), divide 12 kW by 0.15 to find the total capacity of solar panels needed. In this case, it would be 80 kW. 

Based on this calculation, you would require around 80 kW of solar panels to cover your annual energy consumption. However, keep in mind that this is a rough estimate, and it’s advisable to consult with a professional solar installer, such as East Yorkshire Solar, for a more accurate assessment tailored to your specific circumstances. 

How big are solar panels?  

Most domestic solar panels measure around 2 square metres and are rectangular in shape. They’re usually about 2 metres long and 1 metre wide, with a thickness of 3-5cm. The standard residential solar panel weight in the UK is 18 – 21kg. Solar panel weight is extremely important as it is essential that your roof can bear the weight of your solar installation. If you don’t consider this, you risk damaging your roof which can be both dangerous and extremely expensive.  

Conclusion 

Determining how many solar panels you need for your UK home involves assessing your energy consumption, panel efficiency, roof orientation, available space, and panel wattage. While the calculations provided here offer a rough estimate, consult with us to ensure the most accurate and efficient system for your individual needs. Switching to solar power benefits the environment and can lead to substantial savings on your energy bills, making it a wise investment for UK homeowners. 

We offer a FREE on-site survey to determine how many solar panels you need, and we will also advise on other solutions, such as battery storage and EV (electric vehicle) charging. Contact us today or ring our solar experts at 01482 230 422  for more information.