How Much Do Solar Panels Cost in the UK?

Energy Saving Trust’s current guidance puts an average home solar panel system at around £7,600 to install. Its typical example is about 4.5kWp, so the figure is useful as a broad benchmark rather than a target for every house.

Your quote moves with the amount of solar being installed, equipment choice, roof access, scaffolding, electrical work and optional extras. A battery changes the price again and needs its own assessment.

A smaller system is not automatically cheaper per unit of capacity because scaffolding, design, travel and commissioning still have to be paid for. Equally, a larger total does not prove that the extra panels are useful. The benchmark gives you context; the proposed system explains the price.

Start by putting the price beside the system’s rated size. kWp means kilowatt-peak: the rated size of the whole solar array under standard test conditions.

Eight 450W panels = 3.6kWp. Twelve 450W panels = 5.4kWp.

Price per kWp lets you compare how much installed solar capacity each pound is buying. For these two examples:

£/kWp is one of the first numbers we’d calculate when comparing similar solar-only quotes.

It is useful for comparing system size and value, but it is not the final answer. A badly designed system does not become good because its £/kWp is low. Ultimately, cost must be judged against useful generation, avoided imports and export income.

Use the measure only when the quotes cover broadly comparable work. Removing scaffolding, warranties or essential electrical work from one headline figure can make its £/kWp look artificially attractive.

For a good, unshaded roof, we’d usually price the option of filling more of it before deliberately undersizing the system.

If extra panels are sensibly priced and productively oriented, future EV or heat-pump demand can add value. Export payments can also give surplus electricity a value when the home cannot use it.

Poor orientation, shading, disproportionate access or system costs, an inverter that limits output at peak generation, any limit on export to the grid or weak marginal economics can make the last panels poor value.

Every extra panel should earn its place.

Don’t maximise panel count. Maximise useful value.

A complete quote should make clear that it covers the panels, inverter, mounting equipment, scaffolding or other access, cabling and electrical protection, labour, design, commissioning and monitoring.

Optional bird protection, panel-level optimisers and other extras should be itemised rather than disappearing into one headline total. You should be able to see what each addition costs and why it has been proposed.

Paying more can make sense if you’re getting more usable generation, better equipment, a stronger warranty or a better-designed system. But don’t pay for a specification just because it sounds impressive. Ask what the upgrade actually changes.

Adding a battery changes the comparison.

The £7,600 average solar benchmark is for a solar panel system, not necessarily a combined solar-and-battery package. A battery can add several thousand pounds, so separate its price and benefit from the panels.

Ask what the battery costs, how much more of your solar electricity the household is expected to use and whether shifting cheaper tariff electricity into expensive periods adds value.

Solar and battery should each justify their place.

When an installer sends you a quote, find these numbers:

• Total installed price
• Panel count
• Panel wattage
• Total array size in kWp
• Predicted annual generation in kWh
• Inverter rating and model
• Shading assumptions
• Battery capacity, if included
• Any limit on export to the grid
• Key product and workmanship warranties

The generation estimate matters as much as the equipment list. Ask what roof orientation, pitch, shading and system losses have been assumed, and whether the inverter could limit output at peak generation.

If two installers predict materially different annual generation from similar layouts, ask them to explain why. A polished quote is not a substitute for assumptions you can inspect.

You should also know what happens after installation: who registers the system, what commissioning documents you receive, how monitoring is set up and who handles a fault. These details may not change the array’s rated size, but they are part of what you are buying.

We wouldn’t walk into a solar purchase trying to hit £7,600. We’d start with the system the house actually needs, then ask whether the design, generation estimate and price make sense together.

Compare like with like: solar-only against solar-only, similar system sizes against each other, and battery costs separately. Then test what the proposed generation could be worth for your electricity use, export rate and future plans.

Three comparable quotes can be more useful than chasing a national average. Put each installer’s price, kWp, predicted annual kWh and assumptions in the same order. The differences then become questions you can ask rather than promises you have to take on trust.

Don’t buy the cheapest solar system. Buy the system whose numbers make the most sense.