The Cost of a Solar PV System

How much do solar panels cost?

Solar PV panels have reduced in price by approximately 40% as a result of falling manufacturing costs and increased competition in the market. This means you can now get a solar PV system installed on your roof for between £4,000 and £7,000. You can also get payment from the government for every unit of energy you generate, and for sending what you don’t use to the National Grid.

>>> Read our detailed Solar PV case Study <<<

Eligibility for solar PV Feed-in Tariff

In order to make installing solar PV more attractive, the government launched the Feed-in Tariff, which pays households for any electricity produced from the solar PV system. Although payment rates have now been cut drastically, and will no longer pay for the system itself, the extra money is still a bonus if you would like to generate your own electricity anyway.

>>> Learn more about the Feed-in tariff and how to apply <<<.

Export Tariff vs. using the electricity at home

To maximise the return from the solar PV installation, you will want to use as much of the electricity you produce in your home as possible. In the most basic terms, if you use the electricity you produce in the home, then you don’t need to buy it from your energy provider (a saving of around 12.5p/kWh). If you export it, you only get paid a fraction of this – but this isn’t actually the main reason to export the electricity.

>>> Learn how to use 100% of the electricity from your solar PV <<<

How and when households use their solar PV-generated electricity could be about to change hugely, with big developments in battery storage technology. Read more about it here.

Solar PV worked examples

For someone to be in the 75% and above usage range, they would have to be at home almost constantly throughout the week. Going forward, we are going to assume that the typical user uses about 50% of the electricity they produce and exports the other 50%, but in the table below we have shown the financial implications of home use versus exporting the electricity.

So, to start with, we will look at a typical 3kWh system (installed on a new build with a ‘higher’ energy efficiency requirement rating) and see the annual return, based on the percentage you use in the home versus how much you export. Over a year, a 3kW system would expect to be around 90% efficient and generate about 2700 kWh of electricity (an average home used 4,800 kWh per year).

Worked Examples – % of Electricity used in the Home : % of Electricity Exported to the Grid

100% : 0% 75% : 25% 50% : 50% 25% : 75%
Total kWh/year 2700kWh 2700kWh 2700kWh 2700kWh
FiT (4.43p/kWh) £120 £120 £120 £120
Used by household (12.50p) £338 £253 £169 £84
Export tariff (4.85p) £0 £30 £61 £91
TOTAL RETURN £458 £373 £289 £204

These numbers are correct as of 23 March 2017. For the latest rates, click here.

What impacts the initial cost of your solar PV installation?

The cost of your solar PV system is dependent on two things:

1. The size of the installation

Obviously the larger the system you install, the more electricity it has the potential to produce. The average solar PV system installed in the UK now is 3.5KW, which – working at 90% efficiency – will produce approximately 3150kWh of electricity (depending how much sun you get in your part of the country). As reference, an average house uses approximately 4,800kWh. The number of panels you can install will probably be limited by either the amount you can afford or the size of your roof. Suppliers will also charge different prices for their installation services and it’s important to ensure they are MCS-accredited to qualify for the Feed-in Tariff.

2. The quality of the solar panels used

Not all solar panels are the same!

See our guide to the different types of solar panels for more details, but in a nutshell there are three types:

    • Monocrystalline solar cells (made from single crystals grown in isolation) are the most efficient at 15-22%, but they are also the most expensive type of solar cell.
    • Polycrystalline cells are cheaper than monocrystalline, but their efficiency is far lower at just 13-17%.
    • The cheapest solar cells of all are amorphous solar cells, which also have the bonus of being more efficient in low-light (great if you live in the UK!) but they are the least efficient overall at 9%.

How are the efficiency figures calculated? Well it is determined by how many watts of power are produced in a square meter. 100% efficiency means that a square meter of panel would create 1,000 watts. Therefore a panel rated at 18% would create 180 watts from every m2; it follows that panels with higher efficiency ratings create more electricity (per meter squared) and this is reflected in the price.

>>> How solar return changes based on pitch and shading <<<

As you can see in the table above, the actual price of your installation varies depending on the types of panel you get installed, so a 4kW system could cost as little as £5,500, or as much as £7,000.

System A

System B

System C





Type of Panel




Efficiency of Panel




Output (kWh)




Feed-in Tariff (£)




Savings on electricity bill (£)




50% electricity exported (£)




Annual Return (£)





Payback of your Solar System

So having chosen to go for a typical 3.5kW solar PV array for your home, what kind of payback time can you expect?

Well, if you were to make £666 a year via Feed-In Tariff (as in the table 2 above), then a £6,000 pound system will pay back in 9 years. The Feed-In Tariff is guaranteed for 20 years, the payments are tax free and they are linked to RPI, so will actually increase over time.

In addition, electricity prices are expected to go up over time, so the 12.5 pence you save for every kWh of electricity you use in your home will actually increase – and could be nearer 20 pence in just 5 years – therefore the absolute return could actually become bigger.

Once you have ‘made your money back’, then any money you make is paid directly to you as profit – so you will be in line to receive 11 years of quarterly payments directly into your bank account (again, tax-free!).

There are a few other costs to think about with solar PV


There are maintenance costs associated with your solar PV installation, including cleaning them at least twice a year to ensure they are working as efficiently as they can.

Replacing Inverters

In addition, despite the solar panels being good for 20 years plus, the inverters have a lifespan of about 10 years, and replacing these will cost just shy of £1,000 – so factor this in to your calculations when your solar installers give you a quote.

>>> Microinverters can also increase Solar PV return – click to find out more <<<


You will need to insure you solar PV array as part of your home insurance, so your insurance premium payments will slightly increase.

Planning Permission

Installing solar panels on your roof does normally not require planning permission. However if you live in a conservation area or world heritage site, you will need to speak to your planning authority to get the necessary permission. Note: there will also be legal fees associated with this.

Installing Solar PV

Are you thinking about installing a solar PV system at home? We have scoured the country for the best tradespeople, so that we can make sure we only recommend those we really trust.

If you would like us to find you a local installer to help install a solar PV system in your home, just fill in the form below and we will be in touch shortly!

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