Waitz Energy
Free Tool

Solar Panel Payback Calculator

See what installing solar panels would actually cost and save you. Real UK energy prices, no sales pitch.

Your Roof

Auto-calculated from roof area or manual override
Your current monthly electricity spend

Prices: Ofgem Q2 2026 cap. Electricity 24.50p/kWh, SEG 15p/kWh.

Annual Generation

12,000 kWh
Generated
(kWh)
8,000 kWh
Consumed
(kWh)
4,000 kWh
Exported
(kWh)
7.2
years payback
with 2026 rates
£12.4k
lifetime saving
over 25 years
£480
annual savings
after payback

Cost Breakdown

Panels + installation £4,500
Battery storage £1,200
Total £5,700
Estimated SEG income (25 years) £5,000

Monthly kWh Generation

Carbon Reduction

1.9
tonnes CO2/year saved
🌳🌳🌳🌳🌳
Equivalent to 9 trees planted/year

The honest bit

  • - Real generation depends on your roof's exact angle and any shading from trees or buildings.
  • - Battery storage ROI is marginal at current prices - be honest about this.
  • - SEG rates vary, we're using 15p/kWh export as baseline.
  • - Solar panels degrade ~0.5%/year - this is included in our calculations.
  • - 25-year lifespan assumed for all calculations.

Want a proper solar assessment?

A detailed roof analysis tells you exactly what solar panels would do for your property.

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Related reading

Solar Panels in the UK: Honest Numbers & Reality Check Who Pays for Energy Upgrades in UK Properties