Curious what solar would cost for your home — and how fast it pays back?
Use our Solar Cost Calculator to estimate system size, installation price, bill savings, Smart Export Guarantee (SEG) income, and payback period based on your roof and usage. It’s free and takes less than a minute.
👉 Prefer a done-for-you assessment? Get a Free Solar Quote and we’ll design a bespoke system for your home.
How the Calculator Works (At a Glance)
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Inputs: postcode/region, monthly bill (£), roof direction & tilt, roof area (m²), battery (yes/no).
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Outputs: recommended system size (kW), estimated cost (£), annual generation (kWh), bill savings (£), SEG income (£), payback (years).
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Assumptions (editable): UK irradiance by region, panel efficiency, degradation (0.5%/yr), average SEG rate.
Tip: Accuracy improves if you add roof area and orientation.
Inputs We’ll Ask For
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Location (postcode or region)
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Monthly electricity bill (£) or annual kWh usage
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Roof orientation (N/NE/E/SE/S/SW/W/NW)
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Roof tilt (0–45°)
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Usable roof area (m²) (optional)
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Battery storage (yes/no; 5–10 kWh typical)
Quick Solar Estimate
What You’ll Get
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System size (kWp) and panel count
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Installed cost range (low/typical/high)
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Annual generation (kWh)
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Self-consumption vs. export (with/without battery)
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Estimated annual savings (£)
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Projected SEG income (£)
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Simple payback (years) & 25-year lifetime savings
Calculation Logic (Plain English)
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Generation (kWh/yr) ≈
kWp × regional irradiance (kWh/kWp/yr) × performance ratio (0.82–0.9) -
Self-consumption: ~40–55% without battery; 70–85% with battery (typical ranges)
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Savings (£) = self-consumed kWh × import tariff
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SEG income (£) = exported kWh × SEG rate
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Payback (yrs) = installed cost ÷ (savings + SEG income)
These are indicative figures; your quote will include a survey-grade design, shading analysis, and tariff/battery optimisation.
Example (Illustrative)
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Location: Midlands
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System: 4 kWp, 10 panels
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Cost: £6,000 – £7,000
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Annual generation: ~4,000 kWh
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Savings: £650–£800/yr (import 28–33p/kWh)
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SEG income: £80–£150/yr (rate dependent)
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Payback: ~6.5–8 years
Add Battery? (Why It Changes ROI)
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Pros: higher self-consumption (store daytime solar for evenings), better bill reduction, time-of-use optimisation.
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Consider: upfront cost, cycle life, household usage pattern.
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Typical: 5–10 kWh battery adds £3,000–£6,000 but can speed payback for evening-heavy usage.
Ready for a Precise, Survey-Backed Quote?
We’ll confirm roof size, shading, exact yields and grants, then build your ROI model — free.
👉 Get Your Free Solar Quote
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