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3kw Solar Panel Systems

With the cost of living and energy prices at all-time highs in the UK, homeowners are looking for alternatives to power their homes in a more cost-effective way.

Even though the UK Government has been helping those most in need with their energy bills, those that don’t qualify for any help are turning to renewable energy as a more eco-friendly way of powering their homes that will also bring financial benefits.

Many homeowners in the UK are looking at getting a new 3kW solar panel system installed, and it’s not really surprising when you consider that these systems are somewhat affordable, and are perfect for medium-sized homes with two or three people occupancy.

cost of 3kw Solar Panel System

What is The Cost of a 3kw Solar Panel System?

The cost of a solar will vary based on a number of factors, including your roof’s direction, the capacity of the roof (i.e. how many panels you can install), solar panel installation prices, and the required output for your PV system.

The higher the efficiency of the solar panels, the more money you will save in the long run. A 3kW solar panel system usually costs between £4,500 and £7,500 on the UK market. This cost includes the installation fee.

The easiest way to figure out how much it will cost is to chat with a professional installer and get an accurate solar quote. 

Solar panels are one of the most common energy-efficient ways to generate electricity for your home. It is renewable, clean, and steady, making it a great alternative source of electricity for the home.

However, many people are still curious about how much energy is provided by solar panels. While most of this is dependent on individual circumstances and the kind of solar panel used, there are some common features that can help you get a general ballpark figure.

Key Considerations When Looking at 3 kw Solar Panel Systems

When considering the purchase of a 3kw solar system, there are a lot of factors to bear in mind. 

Depending on the size of the area available for installation, a suitable solar energy system must be chosen. 1kW and 2kW solar systems, for instance, are the smallest types and are most typically seen in smaller homes where the number of occupants, and therefore electricity demand, is less.

The overall size of the solar array you purchase will be determined by the size of your home’s roof. A 3kW solar array would necessitate at least 21m2 of roof space or more.

In this case, size really does matter and the size of your installed system will determine how much power is generated by your solar panel system.

The best location for panel installation is on a south-facing section of the roof, therefore this will also affect the total number of panels that can be installed.

how much energy does a solar panel produce

How Much Energy Does a Solar Panel Produce?

A 3kW PV system will generate roughly 2,500 kWh of power per year. The solar panel system will usually be made up of 20 x 150-watt solar panels (low efficiency), 15 x 200-watt panels (medium efficiency), or 12 x 250-watt panels (which are high efficiency and use the latest technology).

If you want to create a 3 kW solar panel array, you will need 12 x 250-watt solar panels to generate that amount of energy.

3kW solar panels are estimated to save you at least £270 per year on your electricity expenditures. In addition to breaking even on your investment, you are likely to profit at least £1,350 throughout the course of a solar panel’s at least 25-year lifespan. The most popular solar panel systems in the UK are the 3kW and 4kW due to the amount of electricity produced per year.

When broken down, we can see that the electricity produced by a 3kw system annually is enough energy to power appliances such as:

  • 4,857 hours use of the washing machine
  • 97,143 hours use of the fridge
  • 1,880 hours of boiling the kettle
  • 1,417 hours use of the oven


Considering that every solar panel array is unique, it can be difficult to calculate exactly how much electricity yours will produce. So, here are a few fundamental facts about typical residential solar panel installation.

  • Domestic systems typically range in size from 1 to 5 kilowatts (kW).
  • A 1kw system can generate approximately 850kw per year, a 2kw system can generate 1,700kw per year, and a 5kw solar panel system can generate around 4,500kw per year.
  • The Energy Saving Trust (EST) predicts that a standard three-bedroom home in the UK will consume little more than 3,000kw annually. Therefore, a 4kW or 5kW solar panel system would be sufficient for most larger household’s needs.
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How Much Money Can You Save with a 3kw Solar Power System?

Depending on the size of your roof, a 3kw solar array typically tends to consist of either 15 x 200W solar panels or 12 x 250W solar panels.

A 3kW system will produce, on average, around 2,500kWh of electricity per year.

This means that you would benefit from approximately £450 of savings per year on your electricity bills, as well as earnings from the FIT (Feed In Tariff), if you managed to register for this prior to 2019 when the UK Government closed to new FIT customers, making way for the new SEG scheme, which we outline in more detail below.

Due to the decent levels of energy that are produced each year, 3 and 4-kW solar panel systems are the most frequently used in UK households.

Smart Export Guarantee

When you sign up for the Government’s Smart Export Guarantee (SEG), you can earn money for feeding excess energy produced back to the National Grid with your 3kW solar system, making your solar investment even more appealing.

In 2019, the SEG replaced the old Feed in Tariff, encouraging UK residents to export surplus electricity produced by a domestic solar PV system to the grid. This new scheme is applicable to those running a 3kW solar panel system as well as others.

The new plan requires main energy providers, with in excess of 150,000 residential customers, to offer a rate to their clients who export excess electricity generated back to the grid. Tariff prices are not fixed, however, and the amount generated through SEG will depend entirely on which utility company you approach.

With so much emphasis on renewable energy by the UK Government, whatever price they settle on needs to be fair for the sake of the consumer.

Advantages of a 3kW Solar Panel System

Here are a few of the advantages of producing solar energy using a 3 kW solar panel system:

  • It’s environmentally friendly: because solar panels produce no pollutants, and using them to power your house or business reduces your carbon impact.
  • Save money: whatever electricity you generate is completely free, and you may use it to power anything in your house or company. This will, of course, reduce your energy expenses and save you money in the long run. You will also be able to profit from the Smart Export Guarantee, which has replaced FIT in most cases, resulting in a faster return on investment.
  • No specific approval is required for the installation of solar panels. There are certain guidelines to follow, but it’s largely straightforward.
  • It is renewable: the sun is certainly not expected to run out anytime soon, and they do still work even on cloudy days, so you should have enough free electricity all year. Install a battery storage system to save any excess electricity produced throughout the day and then it in the evening when the sun isn’t shining. As an added bonus, it will reduce your carbon footprint.
  • Solar panels can produce electricity all year, not just when the sun shines the brightest.

Factors Affecting Solar Panel Efficiency

While a general estimate of the power output of a 3kW solar panel system can be obtained, keep in mind that various factors will definitely affect solar panel efficiency. As an example:

  • The solar panel’s geographic position influences daily solar absorption and defines the system’s potential output.
  • The solar panel should be positioned where the system receives the maximum sunshine. Otherwise, shadow can significantly reduce electricity output.
  • As with all solar panel systems, your 3kW solar array’s alignment and tilt angle are also vital. At the end of the day , it all comes down to how fiercely the sun can impact the panels!
  • Solar panels can be fitted on a flat roof space but need to be installed at a pitch that captures as much sunlight as possible.
  • Individual component performance and features may also be important, as not all brands give the same level of energy effectiveness.
  • Keep a watch on the solar panel to make sure it is not obstructed by foliage, snow, or anything else that could interfere with sunlight exposure.

How to Find the Best 3kW Solar Panel System

A 3kW system is usually the ideal choice for most moderate-sized households if you plan to install a solar battery storage system in the future. Finding the best 3kW solar panel system for your household can be tricky. As we have already mentioned there are a number of differences between 3kW solar panel systems that are on the market in the UK today.

We would always suggest that you speak with a professional solar panel installer when considering solar for your home.  They would be able to offer you advice on the best system for your particular area of the country, how many panels you would need, whether you need a solar battery and inverter, and whether a 3kw solar panel system would be adequate for your needs or you would need one that generates more power.

While it is possible to get a DIY solar power kit to attempt your own installation, this really is not recommended as it is a task that should really only be carried out by someone with the right expertise.

A solar expert will be able to help with any queries you may have about the Government SEG scheme and whether solar panels are indeed right for you and your home.