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Solar cost calculator

Solar panel cost calculatorBuild your kit, see your price.

Pick your home, roof, panels, inverter and battery, and the guide price moves with every choice. A typical 3-bedroom home with 8 panels and a 9.8 kWh battery comes to £6,650 to £7,950, fitted, with scaffolding and MCS certification included.

  • 0% VAT on solar and batteries until 31 March 2027
  • Every step has a sensible default
  • Nothing is sent to us until you book a survey

Step 1: Your home

So we can size the system to what you use.

How big is your home?

Anything that uses a lot of electricity?

kWh a year

It's on your annual statement. Leave it blank and we use a typical figure for your home.

Electricity supply

Almost every UK home is single-phase. If you're not sure, leave it.

Step 2: Your roof

Where the panels go and how they'll sit.

What is your roof covered in?

How many roof areas will have panels?

Which way does it face?

Number of panels

8panels

Recommended for about 2,500 kWh a year.

8 panels
A rough layout. Your surveyor will plan exact positions around vents, windows and chimneys.

Step 3: Your panels

All N-type panels from tier-one makers, with long product warranties.

Which look do you prefer?

Panel size

Brand

Step 4: Inverter and battery

The inverter turns solar power into mains power. A battery stores it for later.

Inverter brand

Inverter model

Every inverter here is a hybrid, so it's battery-ready, even if you start without a battery. Sizes shown are the ones that suit your number of panels.

Battery

Batteries must match the inverter, so these are the Fox ESS batteries that work with this inverter. Choose a different inverter brand to see other batteries.

Optimisers

Step 5: Installation

Access and your fuse board.

Scaffolding

Priced for houses up to two storeys with normal access.

Bird protection

Pigeons love nesting under panels. Mesh runs around the edge of the array to keep them out and is fitted by our roofers on the day.

Your fuse board (consumer unit)

Why might my fuse board need replacing?
  • Two-way power. Solar and batteries send power back through your board. The Wiring Regulations (BS 7671, Regulation 530.3.201) require the protective devices to be suitable for that, and many older breakers and RCDs aren't.
  • Fire-safe enclosure. Boards in homes must be in a non-combustible (usually metal) case (Regulation 421.1.201). Older plastic boards don't meet this.
  • RCD protection and a spare way. The solar circuit needs its own RCD-protected way in the board. Boards with no RCDs or no space can't take it safely.
  • Certification. We can only issue your MCS certificate and notify your network operator (DNO) when the connection meets current regulations, now BS 7671:2018+A4:2026.

We check this at the survey. If it's needed, the replacement is £250, fitted on the same day as your solar.

Guide price

£6,650 – £7,950

See breakdown

How it works

How we work out your price

Your price is built from the parts of the job, not a figure per panel. Every choice you make above changes one or more of these.

Why it's a range until we've seen your home

Each part carries an allowance for what only a survey can show: how far the cable runs from roof to fuse board, the condition of the roof, the access for scaffolding, and whether your fuse board needs replacing. The low end is a straightforward job and the high end is a harder one. After a free survey you get one fixed price.

  1. Equipment

    Panels, mounting rails and hooks, the inverter, any battery and optimisers, bird protection, and the electrical parts (isolators, cable, meter) for the exact layout you pick.

  2. Roofing labour

    Fixing the rails, hooks and panels and fitting the bird mesh. Slate and flat roofs take longer per panel, and a second roof area adds time.

  3. Electrical labour

    Wiring from roof to fuse board, fitting the inverter and battery, then testing and commissioning the whole system.

  4. Scaffolding

    Priced by the number of sides of the house that need it, for homes up to two storeys with normal access.

  5. Design and paperwork

    The system design, your DNO application (G98 or G99), the MCS certificate and warranty registration. MCS is what lets you sign up to an export tariff and get paid for spare power.

What moves the number

What affects the price of solar panels

  • Roof type

    Tiles are the most straightforward. Slate needs flashing on every hook and more careful fixing, flat roofs need tilted frames, and metal sheet uses its own clamps.

  • Number of roof faces

    Splitting panels across two or three roofs adds rails, cable and roofing time, and can mean scaffolding on more sides. The inverter also needs a separate input for each direction unless you fit optimisers.

  • Panel look

    Classic panels are the best value. All-black panels cost a little more and blend into a dark roof. Premium back-contact panels give the most power per panel, which helps on a small roof.

  • Battery size

    The biggest single swing in the price. Size it to what you use after dark, not to the largest battery on offer: a battery you never fill earns nothing.

  • Optimisers

    A small box behind each panel. Worth it where a chimney, tree or dormer shades part of the roof, and not needed on a clear roof facing one way.

  • Three-phase supply

    Three-phase inverters cost more and need a larger array to start, so a small system on a three-phase home is sometimes priced at survey instead.

The method

How we estimate your savings

Four steps: what your panels make, what your home uses, how much of the solar you use yourself, and what that's worth.

  1. What your panels make

    System size in kWp, times a yearly yield of 925 kWh per kWp for a south-facing roof, 770 for east or west, and 850 if you're not sure. These come from our own system designs for UK roofs.

  2. What you use

    1,600 kWh a year for 1 to 2 bedrooms, 2,500 kWh for 3 and 3,800 kWh for 4 (Ofgem's 2026 typical consumption values), or 5,000 kWh for 5 or more. We add 2,500 kWh for an electric car, 3,500 kWh for a heat pump and 600 kWh for working from home. The 5+ bedroom and extras figures are our own estimates, and a figure from your bill replaces all of them.

  3. How much you use yourself

    Without a battery, about 35% of what your panels make. A battery lifts that by 5 percentage points for each kWh of storage, up to 85%, and never past 90% of what you use in a year.

  4. What it's worth

    Every unit you use yourself saves 26.32p, the GB average under Ofgem's price cap for 1 October to 31 December 2026. Every unit you export earns 12p. We show the saving from 15% below to 10% above that figure, and payback as the price range divided by the saving range.

The suggested number of panels is enough to make about 140% of what you use in a year, between 4 and 30 panels.

The estimate errs low on purpose. It assumes electricity prices stay where they are, and it leaves out charging your battery overnight on an off-peak tariff, which can add a good deal to the saving.

Sources

Questions

Solar panel cost questions, answered

How much do solar panels cost in the UK?+

For a typical 3-bedroom home, 8 panels (3.56 kWp) with a 9.8 kWh battery come to £6,650 to £7,950 fitted, and the same panels without a battery £4,350 to £5,300. That includes scaffolding, the inverter, all the electrical work, the DNO application, MCS certification and 0% VAT. Bigger homes, slate or flat roofs and larger batteries cost more, so use the calculator above to price yours.

How many solar panels do I need?+

Enough to make roughly 1.4 times what you use in a year. A 3-bedroom home using about 2,500 kWh a year usually needs 8 panels of about 445 watts on a south-facing roof. An electric car or a heat pump raises that quickly, which is why the calculator suggests a new count whenever you change your home or usage.

Is there VAT on solar panels and batteries?+

No. Solar panels and batteries fitted to homes carry 0% VAT until 31 March 2027, including a battery added to existing panels. Every price in the calculator already reflects that.

Is a solar battery worth it?+

Usually, if you're out during the day. Without a battery you use about a third of what your panels make and export the rest at about 12p a unit. A battery lets you use up to 85% yourself, worth 26.32p a unit at the current price cap. On the typical 3-bed system, the estimated saving is £610 to £790 a year with a 9.8 kWh battery, against £480 to £620 without one.

How long do solar panels take to pay for themselves?+

On the typical 3-bed system with a battery, 8 to 14 years. That holds today's electricity price flat and leaves out off-peak battery charging, so it errs on the long side. A south-facing roof and higher daytime use bring it down.

Why is it a range and not a fixed price?+

Because a few things only a survey can show: the layout and condition of your roof, the cable route from roof to fuse board, the access for scaffolding, and whether your fuse board needs replacing. The low end of the range is a straightforward job and the high end a harder one. After a free survey you get one fixed price.

Keep reading

Guides and tools for solar

Want the fixed price?

A free survey checks your roof, fuse board and shading, and turns the range into one price. Or call us free on 0800 999 1129.

Book a free survey