Bill Breakdown Calculator
See exactly where your electricity bill goes with solar
Bill breakdown
See exactly where your electricity bill goes with solar. Adjust the sliders to match your situation.
3,500 kWh
4 kW (9 x 450W)
None
How this works
This calculator starts with your current annual electricity bill at the UK standard rate of 24.5p/kWh, then subtracts what solar self-consumption would save you, plus what you would earn from exporting surplus electricity at 12p/kWh via the Smart Export Guarantee.
The split between self-consumption and export depends heavily on battery size. Without a battery, you self-consume about 40% of what you generate. With a 10 kWh battery, that rises to around 75%.
The final bar shows your estimated bill after all savings — the figure you would actually pay each year.
Things to consider
- •Standing charges are not included in this calculator — they are fixed and cannot be reduced by solar.
- •Real export rates vary by tariff. Octopus Flux pays up to 15p/kWh, while standard SEG rates can be as low as 3p/kWh.
- •This assumes a south-facing roof in average UK conditions. East/west-facing roofs generate about 82% as much.
- •Battery savings depend on your evening usage pattern — if you use less than your battery holds, you will not capture the full benefit.
Dig deeper
Understanding Your Electricity Bill with Solar
How to read your electricity bill when you have solar panels. Understand import, export, generation, self-consumption, and why your bill might not be as low as expected.
Solar Panel Payback Calculator UK
Calculate your solar panel payback period in the UK. Understand the real factors that determine how quickly solar pays for itself — with worked examples.
Standing Charges: What You're Paying Before Using a Single kWh
What electricity standing charges are, why they exist, how they affect solar panel savings, and whether zero standing charge tariffs are worth it in 2026.
Smart Export Guarantee (SEG) Explained
How the Smart Export Guarantee works in the UK, which suppliers pay the best SEG rates, and how to maximise your solar export income in 2026.
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