Solar Panel Savings Calculator

Enter your details below for a personalised estimate of how much you could save with solar panels - including costs, annual savings, payback period, and 25-year return.

Your Details

Postcode (for local irradiance data)

We use this to look up your area's solar irradiance from PVGIS satellite data

Monthly Electricity Bill:

£30/moUK avg: £100/mo£500/mo

System Size:

2 kWPopular: 4 kW12 kW

Main Roof Direction

Roof Pitch:

Flat (0°)Optimal (35°)Steep (60°)

Roof Shading

Include battery storage

Battery Size:

3 kWhPopular: 5 kWh15 kWh

Advanced options

Electricity Rate (p/kWh):

SEG Export Rate (p/kWh):

Annual Energy Inflation:

25-Year Savings Projection

Cumulative savings System cost

Your Solar ROI

Enter your details and click Calculate

Fill in your details for a personalised estimate using satellite irradiance data for your postcode.

How This Calculator Works

Solar Generation

We estimate annual kWh output using your system size, roof direction, and regional solar irradiance data from PVGIS.

Bill Savings

Savings calculated using your self-consumption rate (40% without battery, 75% with) at the current average electricity price of 24p/kWh.

ROI Analysis

Payback period and lifetime savings include SEG export income (8p/kWh average) and account for 0.5% annual panel degradation.

Calculator FAQ

Our calculator provides a good estimate based on UK averages for solar irradiance, electricity prices, and typical system performance. For a precise quote, we recommend getting a site survey from an MCS-certified installer who can assess your specific roof, shading, and usage patterns.

The calculator uses the current UK average electricity rate of approximately 24p/kWh. If your tariff is higher (e.g., standard variable), your actual savings may be greater. If you are on a fixed deal below this rate, savings may be slightly less.

Yes, you can toggle battery storage on or off to see how it affects your savings. Adding a battery typically increases self-consumption from 40% to 75%, significantly boosting annual savings.

Related Solar Guides

Costs

Solar Panel Costs 2026

Full breakdown by system size.

Grants

Grants & Funding Guide

0% VAT, SEG, ECO4 and more.

Battery

Battery Sizing Guide

What size battery do you need?

Ready for Real Quotes?

Our calculator gives you a great starting point. For exact pricing, get up to 3 free quotes from MCS-certified installers who will assess your home.

Get Free Solar Quotes