- Solar Heating Calculator
Solar Heating Calculator
Calculate your solar heating potential, cost savings, and return on investment. Discover how solar energy can reduce your heating costs and environmental impact.
Solar Heating Calculator
Calculate solar heating potential and savings
Monthly energy usage
Cost per kilowatt-hour
Total living space size
Solar Heating Benefits
Discover the advantages of solar heating systems for your home
Eco-Friendly
Reduce your carbon footprint with clean, renewable solar energy
Long-term Savings
Significantly reduce heating costs over 20+ years
Energy Independence
Reduce dependency on traditional energy sources
How Solar Heating Works
Understanding the technology behind solar heating systems
Solar Collection
Solar panels collect sunlight and convert it to energy
Heat Transfer
Energy is transferred to your heating system
Distribution
Heated water or air is distributed throughout your home
Savings
Reduced energy bills and environmental impact
How to Use the Solar Calculator
How to Use the Solar Calculator
- 1
Assess Roof Space
Measure available south-facing roof area (best), or east/west facing (10-20% less efficient). Need 20-40 m² for typical domestic system. Check for shade from trees or buildings - even partial shade reduces output significantly. North-facing roofs generally unsuitable in UK.
- 2
Find Solar Irradiance
Look up your location's average daily solar irradiance (kWh/m²/day). UK averages: South England 2.8-3.2, Midlands 2.6-2.9, North England/Wales 2.4-2.7, Scotland 2.2-2.5. Lower than continental Europe but still viable with current technology and tariffs.
- 3
Select Panel Efficiency
Choose solar panel efficiency: Budget 15-17%, standard 17-19%, premium 19-22%. Higher efficiency = more power from limited roof space. Premium worth considering if roof area restricted or partial shading present.
- 4
Input Electricity Rate
Enter current electricity cost per kWh from your bill (typically £0.24-£0.34/kWh). Solar savings directly tied to electricity rate - higher rates = faster payback. Consider export tariff (£0.04-£0.15/kWh) for unused generation via Smart Export Guarantee.
- 5
Calculate ROI and Savings
Review system cost (typical 4kW system £5,000-£8,000 installed), annual energy production, savings, and payback period. UK systems typically pay back in 9-15 years. Panels last 25-30 years, providing free electricity for 10-20 years after payback. Best ROI with high electricity usage during daytime or battery storage (additional £4,000-£8,000).
Pro Tip: Use Ctrl+Enter to calculate quickly, or Ctrl+R to reset the form.
Frequently Asked Questions
Are solar panels worth it for heating?
Solar panels generate electricity, not directly heat. However, they can power heat pumps (300% efficient) for net heating savings of 60-80%. Best strategy: solar + heat pump combination. Solar alone offsets heating costs if you use electric heat. Payback typically 8-12 years with grants.
How much roof space do I need for solar?
Average home needs 20-40 m² for sufficient solar capacity. Typical 6kW system requires about 30 m². South-facing roof is ideal, east/west works with 10-20% efficiency loss. Check for shade from trees/buildings - even partial shade significantly reduces output.
What happens to solar panels in winter?
Solar panels work in winter but produce less energy (40-60% of summer output) due to shorter days and lower sun angle. Cold temperatures actually improve panel efficiency! Snow coverage blocks production but typically melts quickly from panels. Winter is when you need most heating, so battery storage or export tariffs are crucial.
Do I need battery storage with solar panels?
Not required but recommended. Grid-tied systems without batteries: cheaper (£15k-25k), export tariffs sell excess to utility, no power during outages. With batteries: add £10k-15k, backup power during outages, energy independence, better ROI if utility rates high/export tariffs poor. Batteries make sense for: frequent outages, high time-of-use rates, off-grid living.
How long do solar panels last?
Solar panels last 25-30 years with minimal maintenance. Performance degradation: ~0.5% per year, so panels at 25 years still produce 85-90% original output. Inverters need replacement after 10-15 years (£1,500-3,000). Warranties: 25-year performance guarantee (80% output), 10-15 year equipment warranty. Total system lifespan: 25-30 years with proper maintenance.
If Thermopy helped you, consider sharing your experience on Trustpilot.