Solar panel price comparison UK

Why headline prices are messy

Solar panel price comparison sounds simple until you look at two real quotes. One quote may include scaffolding, bird protection, monitoring and a long workmanship warranty. Another may show a lower headline price but leave important items vague.

The fair comparison is the installed system you will actually get, not a row of panel prices pulled from a catalogue.

Compare like for like

Start with system size in kWp, inverter AC rating, expected annual generation in kWh, battery capacity if included, and the total installed price. If those numbers aren't clear, the quote isn't ready for comparison.

Energy Saving Trust currently says domestic solar panel systems are generally around 3.5kWp and cost around £6,100 on average. That gives a useful sense check, but your own roof, access and equipment choices can move the price.

• System size in kWp.
• Expected annual kWh.
• Inverter size and export limit.
• Installed price including VAT treatment.
• Warranty and aftercare terms.

Use cost per kW carefully

Cost per kW is a quick way to compare quotes of different sizes. Divide the solar-only installed price by system size. A £7,000 quote for 4kW is about £1,750 per kW.

That doesn't mean the lowest cost per kW wins. A cheap system with a weak generation estimate, poor monitoring, unclear DNO paperwork or limited aftercare may be poor value.

Check annual kWh, not just capacity

A bigger system normally generates more, but roof direction, shade and inverter choices still matter. A clean 4kW roof can beat a badly shaded 5kW roof.

Use PVGIS or a survey-based installer estimate as a check. If a quote's savings claim depends on very high generation, ask how it was modelled.

Battery add-ons need their own line

A battery can be useful, but it should not be hidden inside a blended solar price comparison. Compare solar-only first. Then compare the battery as an extra decision with its own cost, usable capacity and expected uplift.

Energy Saving Trust says battery storage costs range widely, with a 5kWh system around £4,600. The right number for your calculator is the installed battery price on your own quote.

A better quote comparison checklist

Before choosing an installer, make the quotes boringly comparable. Put the same fields side by side and ask for missing detail in writing.

• Full installed price and payment schedule.
• Solar-only price and battery add-on price.
• MCS certificate or accepted equivalent route for SEG.
• DNO route, export limit and handover documents.
• Panel, inverter, battery and workmanship warranties.
• Savings assumptions for import rate, export rate and self-consumption.