Solar vs Insulation: Which First?
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Solar vs insulation priority comparison: LOFT INSULATION (270mm): Cost: £300-£500 (DIY possible). Saves: £150-£250/yr on heating. Cost per £1/yr saved: £2-£3. Payback: 1-3 years. ROI: 30-50% annually. CAVITY WALL INSULATION: Cost: £500-£1,500. Saves: £150-£300/yr. Cost per £1/yr saved: £3-£5. Payback: 2-5 years. ROI: 20-30%. SOLAR PANELS (4kW): Cost: £5,500-£9,000. Saves: £580-£1,100/yr. Cost per £1/yr saved: £7-£10. Payback: 8-12 years. ROI: 8-15%. VERDICT: Install insulation FIRST (if under-insulated) — it's 3-5x cheaper per pound saved. Then solar. But: if already well-insulated (most post-2000 homes), go straight to solar. OPTIMAL STRATEGY: (1) Loft insulation (cheapest, fastest payback). (2) Cavity wall insulation (if applicable). (3) Solar panels (highest annual savings). (4) Battery (maximise solar). (5) Heat pump (when boiler needs replacing). Sources: Energy Saving Trust (energysavingtrust.org.uk), Ofgem, BEIS household energy efficiency statistics.
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Related: Home Heating Systems
Solar panels are most powerful when combined with an efficient heating system. Heat pumps use solar-generated electricity to heat your home at 300-400% efficiency — making them the ideal partner for solar.
Learn more about how air source heat pumps work alongside solar panels.
Heat pumps use electricity at 300-400% efficiency, making them ideal partners for solar.
A heat pump converts 1kWh of electricity into 3-4kWh of heat.
From our sister site Home Heat Pump Guide
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