Solar Panel Cost Calculator

Our Solar Panel Calculator helps you estimate the cost of installing solar panels and how much you could save on your energy bills in the UK. It also shows how long it might take for your system to pay for itself.

With just a few details, you'll get a personalised breakdown, including:

• Installation cost – the all-in quote you enter for the system you are considering
• Annual energy production – the amount of electricity your panels could generate each year
• Bill savings – how much of your electricity costs you could cut by using your own solar energy
• Export earnings – how much you could earn by selling excess energy back to the grid under the Smart Export Guarantee (SEG)
• Payback time – how long it will take for your savings and earnings to cover your initial investment

Solar panels can help you lower your bills, reduce your reliance on the grid, and even earn export income. Use this calculator for a quick cost and payback estimate. To assess an exact address using building and roof data, try our UK solar roof calculator instead.

How does the Solar Panel Calculator work?

To get a useful estimate, enter details about your home, energy use and the all-in quote for the system you are considering. The regional and roof defaults are simplified model assumptions, not values that fit a majority of homes.

Here's why each one matters:

• Region of your property – Some parts of the UK get more sunlight than others. If you live in the south, your panels will produce more energy than if you live in the north.
• Household electricity usage – This is how much electricity your home uses each year. If you use a lot, solar panels can help you save more by generating your own power. The Low, Medium and High options are Ofgem’s typical consumption values – 1,600, 2,500 and 3,800 kWh a year since 1 July 2026. Your own figure from a recent bill will always beat a band.
• Electricity price (p/kWh) – The price you pay for electricity affects how much money you can save. If prices go up, having solar panels will save you even more. The default is Ofgem’s GB average Direct Debit price-cap unit rate, which is what the calculator’s own assumptions note beside your answer says – your own tariff rate will always beat an average.
• Number of solar panels – This decides the modelled system size. Use the proposed panel count and rated power from your installer's design.
• Battery storage – Each choice applies a disclosed self-consumption scenario. Include any battery price in your all-in quote; the calculator does not invent one.
• Roof orientation – The direction your roof faces affects how much sunlight your panels get. South-facing roofs are best in the UK, but east- and west-facing roofs can still work well.
• Roof angle (degrees) – The simplified model applies its full angle factor from 30–40° and lower factors outside that range. This is a model setting, not a site-specific generation assessment.

By entering these details, you'll get a personalised estimate of how much solar panels could save you and whether they're a good option for your home.

How much do solar panels cost in the UK?

For context, DESNZ’s 2025/26 MCS-certified 0–4 kW DNC band has a published median of £1,780 per kW and mean of £2,008 per kW. DNC is not panel nameplate capacity, so the calculator does not multiply either statistic into a whole-system quote. Enter an all-in installer quote for payback; published £/kW statistics are context, not a quote.

How much can solar panels save me?

Savings depend on how much of the solar energy you use directly (self-consumption) rather than exporting. The calculator's no-battery and battery choices apply disclosed 40–80% model scenarios; they are not measured household averages. Any energy you export to the grid earns whatever your supplier’s Smart Export Guarantee (SEG) tariff pays. There is no single SEG rate: suppliers set their own and the spread is wide, so the rate you are offered matters as much as the size of your array. The calculator starts from the historical Ofgem Year 5 untied-rate average disclosed in its assumptions — change it to your own current export tariff before reading the payback.

Which regions get the most solar energy in the UK?

This simplified model starts with regional annual-yield assumptions ranging from 800 to 1,200 kWh per kWp and then applies roof-orientation and angle factors. These are transparent local assumptions, not an ingested irradiance series or a site survey. Regional yield, orientation, angle, panel size and self-consumption are transparent local modelling assumptions, not measured UK averages or an installer quote.