How Much Does A 5 kW Solar System Cost?

A 5 kW solar panel system is one of the most common system sizes installed on UK homes, ideal for medium to larger households with higher-than-average energy consumption. 

But how much does a 5 kW solar system actually cost? Understanding the true cost and value of this investment is vital for homeowners, landlords, and commercial property owners looking to save on energy bills and reduce carbon emissions.

In this guide, we break down everything you need to know about the price, performance, and savings potential of a 5 kW solar system, helping you make an informed decision.

How Much Does a 5 kW Solar System Typically Cost in the UK?

The average cost of a 5 kW solar system in the UK ranges from £7,500 to £8,500, depending on the quality of components, installer rates, and installation complexity. This excludes adding battery storage.

On average domestic solar PV systems in the UK cost between £5,000 and £6,000 for a 4 kW system (excluding a storage battery), with 5 kW systems coming in slightly higher.

Estimated Cost of a 5 kW Solar System Including Battery Storage

If you add a 5 kWh battery, here’s what the total cost might look like:

Note: Battery prices can vary depending on brand, type (e.g., lithium-ion vs lead-acid), and capacity. Larger battery systems will increase the total cost further.

What Factors Affect the Cost of a 5 kW Solar Panel System?

Several variables can impact the total price you pay:

1. Panel Type & Efficiency

Not all solar panels are created equal. The type and efficiency of the panels you choose play a major role in both the upfront cost and long-term performance:

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  Monocrystalline panels are the most efficient and space-saving option, typically offering 18–22% efficiency. They’re sleek in appearance but come with a higher price tag.
  
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  Polycrystalline panels are slightly less efficient (13–17%) but more budget-friendly.
  
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  Thin-film panels, while lightweight and flexible, are less commonly used in residential settings due to their lower efficiency and larger space requirements.

If roof space is limited, high-efficiency panels like monocrystalline are often the better long-term investment, even though the initial cost is higher.

2. Roof Type, Size, and Installation Complexity

The ease of installation directly affects labour and setup costs:

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  A large, south-facing, unobstructed roof will keep installation straightforward and cost-effective.
  
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  Properties with multiple roof angles, chimneys, skylights, or shading from trees may require more time, customised mounting hardware, or specialist installers, which increases labour costs.
  
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  In cases where roofs are fragile, steeply pitched, or require scaffolding or structural reinforcement, installation costs will rise accordingly.

Additionally, listed buildings or properties in conservation areas may need planning permission, which could add time and fees.

3. Inverter Type

The inverter is a crucial component that converts the direct current (DC) from your panels into usable alternating current (AC) electricity. The type of inverter impacts your system’s efficiency and price:

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  String inverters (cheaper, common in smaller systems) connect all panels to one central inverter. If one panel underperforms (e.g., due to shade), it affects the entire string.
  
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  Microinverters attach to each panel, allowing independent operation and better output in partially shaded conditions, but they’re more expensive.
  
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  Hybrid inverters can work with battery storage, making them ideal for future-proofing your system if you plan to add storage later.

The right choice depends on your property, budget, and whether you’re installing a battery now or in the future.

4. Battery Storage

While not required, adding a solar battery can greatly increase your energy independence. A battery allows you to:

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  Store excess solar energy for use at night or on cloudy days
  
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  Avoid peak-time electricity rates
  
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  Maximise your return on investment if you use more of your generated electricity

However, solar batteries can cost anywhere between £3,000 and £6,000, depending on capacity and brand. This can nearly double the total system cost. 

While the Smart Export Guarantee (SEG) lets you earn money by sending excess energy back to the grid, using that energy yourself via a battery often provides even better savings.

Batteries typically last 10–15 years and may be eligible for green financing options depending on the provider.

5. Solar Irradiance

Solar irradiance refers to the amount of solar energy received per square metre at your location. This affects how much electricity your panels will generate, and therefore, how much value you get from your system.

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  Southern England receives the most irradiance, meaning higher solar output and better ROI.
  
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  In contrast, areas in northern Scotland or urban environments with frequent cloud cover or shading may see reduced generation.
  
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  You can check your region’s solar potential using the UK Government’s solar calculator from the Department for Energy Security and Net Zero:

It's essential to have a professional installer assess your location-specific solar yield and shading analysis to give an accurate estimate of expected system output.

Average Solar Irradiance Across UK Regions

These figures are average estimates based on UK solar irradiance data and typical 5 kW system performance. Actual results may vary depending on shading, panel efficiency, roof orientation, and weather conditions.

How Much Electricity Will a 5 kW Solar System Produce in the UK?

On average, a 5 kW solar system in the UK generates 4,200 to 4,600 kWh per year, depending on location, panel orientation, and weather conditions.

Can a 5 kW Solar System Fully Power My Home?

In many cases, yes, a 5 kW solar system can meet most or all of a typical UK household’s annual electricity needs. 

The average UK household consumes around 2,900–4,200 kWh of electricity per year, though larger households or those with high energy use (e.g., electric heating or EV charging) may use 4,000–4,500 kWh or more. 

A well-positioned 5 kW solar system can generate approximately 4,000–5,000 kWh annually in southern and central UK regions with good irradiance and an optimal setup (south-facing, 30–40° tilt, minimal shading). 

In northern regions or with less ideal conditions, output may be closer to 3,500–4,250 kWh per year.

However, several factors influence whether your system will fully cover your energy use or just offset it significantly. 

These include your location, panel orientation, shading, household consumption patterns, and whether you have battery storage to store excess energy for evening or winter use. 

Without storage, you may still rely on the grid for 20–40% of your needs due to seasonal variations and evening usage, but a well-designed system with storage can achieve near 100% self-sufficiency for many homes.

Your Energy Consumption Profile

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  Low to moderate energy users (e.g. working couples, families who aren’t home all day) will likely see most or all of their electricity needs covered.
  
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  High-demand households with electric heating, hot tubs, tumble dryers, or EV chargers may require additional energy from the grid, especially in winter months when solar generation dips.

Solar Generation vs Time of Use

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  Solar panels generate power during daylight hours, meaning homes or businesses that use most electricity during the day (e.g. small home offices, retired couples, cafés) benefit most.
  
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  If most of your energy use happens at night, you’ll need to either rely on the grid or add battery storage to store excess solar energy for evening use.

Summary

While a 5 kW system can often power a home on paper, in practice, usage habits, time of use, seasonal variation, and location will determine if you still draw from the grid. 

A professional installer can provide a tailored solar yield analysis to determine whether 5 kW is enough, or if a larger system or battery would be a better investment.

How Much Can You Save With a 5 kW Solar System?

You could save £600 to £700 per year on electricity bills, assuming optimal system output and consumption. This is based on a current average unit electricity price of 27p per kWh (as of August 2025).

If you also export surplus electricity under the Smart Export Guarantee (SEG), you can earn an extra £80 to £200 per year, depending on your tariff.

How Long Does It Take to Break Even on a 5 kW Solar System?

The payback period for a 5 kW system typically falls between 7 to 10 years. With rising electricity prices and government incentives, this can be shorter for some households.

Are There Grants or Incentives Available to Reduce the Cost of Solar Panel Installation?

Yes, several UK-wide and regional schemes are available to help offset the cost of a solar panel installation. These programmes support both homeowners and landlords, particularly those in low-income or energy-inefficient homes.

Below is a summary of the most relevant solar panel grants, funding programmes, and incentives currently available in the UK:

Are There Any Ongoing Costs or Maintenance With a 5 kW Solar System?

Solar panels require minimal maintenance. Most systems come with a 25-year performance warranty. Inverter replacements may be needed after 10–15 years, costing around £800 - £1,200.

It’s recommended to:

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  Clean panels annually.
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  Monitor performance with smart systems.
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  Book periodic professional inspections.

How Long Does It Take to Install a 5 kW Solar System?

The installation of a 5 kW solar system typically takes 1 to 2 days. However, the entire process, including site survey, approval, and DNO application may take 2 to 4 weeks.

You’ll need:

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  A roof area of 25–35 m²
  
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  No major obstructions (e.g., chimneys, trees)
  
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  South, southwest, or southeast-facing roof for optimal performance

Is a 5 kW Solar System Right for My Property?

Who it's for

A 5 kW solar system is well-suited for:

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  3 to 5-bedroom homes with moderate to high electricity consumption
  
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  Households with energy-intensive lifestyles, such as EV charging, electric heating, or home offices
  
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  Properties with 25–32 m² of unobstructed roof space, ideally south-facing
  
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  Small businesses such as retail shops, salons, cafés, or small offices that operate mainly during daylight hours
  
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  Homeowners or business owners looking for a cost-effective way to reduce overheads and lock in long-term energy savings

Who it's not for

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  Smaller homes (1–2 bedrooms) with low energy usage
  
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  Properties with limited roof space or heavy shading from trees or nearby buildings
  
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  Households with budget constraints where a smaller system (e.g. 3 kW or 4 kW) may offer better ROI
  
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  Homes where structural roof modifications would be required, adding complexity and cost
  
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  Locations where larger systems (e.g. 8–10 kW) would better suit energy needs (like warehouses or large retail units)

Choose it if...

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  You consistently use 4,000+ kWh/year of electricity and want to offset a large portion of it
  
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  You’re planning for future energy needs, like adding an EV or air source heat pump
  
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  You have enough roof space to comfortably fit the system without compromising aesthetics
  
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  You’re aiming for a solid return on investment and long-term energy independence
  
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  Your small business operates mostly between 9 AM and 5 PM, allowing you to use most of the energy generated
  
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  You want to offset commercial electricity costs, which are typically higher than domestic rates

How to Compare Solar Panel Prices and Find Trusted Installers?

Finding the right installer is just as important as the system itself. With Eco Answers, you can:

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  Compare quotes from multiple trusted UK solar installers.
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  Ensure you're not overpaying for your 5 kW system.
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  Access a simple, free-to-use tool to get quotes tailored to your home.

Try our Solar Panel Quote Comparison Tool today to receive competitive, no-obligation offers from reputable suppliers. It only takes a few minutes!

FAQs

1. Do I need planning permission to install a 5 kW solar system?

Most domestic solar installations fall under Permitted Development and don’t need planning permission, provided they meet certain criteria. Always check with your local authority.

2. Will solar panels add value to my home?

Yes, research from the Department for Business, Energy & Industrial Strategy (BEIS) shows energy-efficient upgrades, including solar panels can increase property value and appeal.

3. What is the lifespan of a 5 kW solar panel system?

Panels can last 25-30 years, with inverter replacements needed around every 10-15 years. Performance may decline slightly over time but remains effective.

4. Is it better to pay upfront or finance a 5 kW system?

Paying upfront offers the fastest ROI, but financing spreads the cost. Be sure to factor in interest rates and total repayment amounts if choosing finance.

Our Verdict

A 5 kW solar panel system is an excellent long-term investment for UK homeowners and landlords seeking energy independence, bill savings, and greener living. 

While upfront costs vary, the combination of government incentives, increasing electricity rates, and modern solar tech make it a smart financial move.

Use Eco Answers' free quote comparison tool to ensure you're getting the best deal for your solar panel installation. It’s fast, easy, and helps you connect with vetted, reliable UK suppliers.