How We Calculate This
Annual generation is estimated from system size and an illustrative production factor, adjusted for roof orientation and shading.
SOLAR PANELS COST & SAVINGS CALCULATOR
Could Solar Panels Save You Money?
Explore installation costs, electricity generation, bill savings and potential export income using figures you can tailor to your home.
£ Understand Costs☀ Estimate Generation↗ See Bill Savings & Exports
Tell Us About Your Solar Plans
Start with typical example values, then adjust using a solar installer quote or your electricity bill.
1. Your Solar System
Most household systems are a few kWp; ask an installer about suitable roof space.
Broad planning examples, not a location-specific forecast. Use PVGIS or an installer report for better accuracy.
Use the annual usage figure on your bill.
2. Costs & Support
Editable illustration, not a quote. Energy Saving Trust cites around £7,600 for a typical 4.5 kWp system; your actual 4 kWp price could differ. Cost guidance.
3. Electricity Prices & Export
SEG eligibility and an export tariff are not automatic. Choose no export payment for a cautious scenario.
Ofgem GB national-average Oct–Dec 2026 example, not your personal tariff.
8p is a hypothetical scenario, not a supplier offer. No payment is guaranteed without an eligible export arrangement.
Personalise Your Estimate — Optional
Illustrative 40% without a battery. Usage patterns are important.
Illustrative south-facing reference yield. Roof direction and shading reduce it unless you enter an installer forecast below.
Use the annual AC electricity generation on a roof-specific installer or PVGIS forecast. When entered, this takes priority: roof direction, shade and regional yield are not applied again. It must not exceed 1,500 kWh per kWp in this illustrative GB model.
For a planning estimate, use the example yield, roof direction and shade. For a quote-based estimate, supply a forecast with its roof and shading effects already included. PVGIS planning tool (European Commission).
✓ Results Update Automatically As You Adjust Your Figures
Your Estimated Results
Solar Scenario Assumptions
Calculations are illustrative and depend on your actual roof, tariffs and electricity usage.
Before installation: obtain a roof and shading survey, installer forecast, itemised quote, and check DNO/export arrangements. Financial and carbon figures are illustrative, not guaranteed.
Estimated Installed Cost—No grant or funding assumed
Annual Electricity Generated—Illustrative solar PV output
Estimated Bill Savings—Solar electricity used at home, per year, based on your chosen self-use percentage
Potential Export Income—Hypothetical only; requires an eligible export contract
Carbon Impact
—Estimated CO₂ equivalent per yeari
An illustrative estimate based on average grid electricity. It is not a full lifecycle carbon calculation.
Solar Electricity Used at Home—Annual kWh, limited by your household electricity use
TOTAL ESTIMATED BENEFIT—
SIMPLE PAYBACK PERIOD—
A combined illustration of electricity bill savings and possible export payments.
Based on your assumptions. Actual generation, savings and payback will depend on your roof, location, usage, export payments, electricity tariffs and future energy prices.
Estimated Annual Benefit Over 25 Years
Light bars show the cumulative financial benefit year by year; the dark line marks your upfront installation cost. Years run along the bottom, £ values up the side.
Cumulative benefit Upfront installation cost
Solar Electricity Exported—kWh per year
Grid Electricity Still Needed—kWh per year (simplified)
What These Results Mean
Enter your figures to see an explanation tailored to your home.
Things to Consider
- Your roof direction, slope, shading and local weather affect generation; an installer forecast is more reliable.
- Self-consumption depends on when you use electricity.
- Export payments require a suitable meter and an approved SEG/export contract; the 8p example is not a guaranteed rate.
- Request an installer survey, check DNO notification/registration, and ask whether export limits apply.
Your Next Steps
- Check Your Roof & Bills
- Request an Installer Survey
- Compare Detailed Quotes
- Check Export Tariff Rules
Important Assumptions
- Regional and shading factors are broad planning examples, not an installer forecast; a quote-based annual generation figure is preferable.
- Excludes panel degradation, maintenance, inverter replacement, financing, electricity tariff changes, and export restrictions. Annual solar use is an approximation that ignores when electricity is generated and needed.
- The carbon figure is an average-grid emissions equivalent, not measured avoided emissions or a full lifecycle result.
- Does not model Northern Ireland export arrangements.
Useful Links & Guidance
Detailed Financial Analysis — Simple Payback & Sensitivity
Simple payback is secondary, and not a forecast of lifetime financial return.
Results exclude maintenance, inverter replacement, degradation, finance and future tariffs. A full investment comparison needs costs and benefits over the expected system life.
Carbon Methodology & Limitations
Illustrative UK grid-emissions equivalent = annual solar generation × 0.13096 kg CO₂e/kWh (UK Government 2026 location-based reporting factor). This describes the emissions associated with the same quantity of average grid electricity; it does not establish actual avoided emissions from this solar installation. Real system-wide effects depend on the hour of generation, exports and the changing electricity mix. Actual displacement depends on timing of production, imports, exports and the evolving electricity grid. Excludes manufacturing, installation, battery impacts and end-of-life emissions. UK 2026 conversion factors.