Solar Panel ROI Calculator

A typical 4kW residential solar panel system costs between £4,000 and £6,000 installed. Prices have fallen significantly over the past decade. The average cost per kW installed is around £1,200. Larger systems (6-8kW) can cost £6,000-£10,000 but offer better value per unit.

The average payback period for solar panels in the UK is 8-12 years, depending on system size, location, electricity usage patterns and the export tariff you receive. South-facing roofs in southern England achieve the fastest payback. With current electricity prices, many systems pay back in under 10 years.

A 1kW solar panel system generates approximately 850-1,050 kWh per year in the UK, depending on location and roof orientation. A typical 4kW system generates 3,400-4,200 kWh annually. Southern England receives more sunlight, so systems there generate approximately 15-20% more than those in Scotland.

The Smart Export Guarantee requires licensed electricity suppliers with 150,000+ customers to offer a tariff for exported solar electricity. Rates vary between suppliers, typically 3-15p per kWh. You need a smart meter to qualify. Shopping around for the best SEG tariff can significantly improve your solar ROI.

Yes, significantly. South-facing roofs are optimal, capturing 100% of potential output. South-east and south-west orientations achieve approximately 95%. East or west-facing roofs still produce around 85% of optimal output. North-facing roofs are generally not suitable for solar panels in the UK.

A battery stores excess solar energy for evening use, increasing self-consumption from roughly 40-50% to 70-80%. A typical 5kWh battery costs £2,500-£4,000 and can save an additional £200-£400 per year. The payback period for a battery alone is currently 8-12 years, though costs are falling.

Yes, solar panels work in winter but produce significantly less electricity. A typical system generates about 10% of its annual output during December and January combined, compared to around 15% in June alone. They still generate useful electricity on cloudy days, just at reduced capacity.

Most domestic solar panel installations in England are permitted development and do not need planning permission, provided they do not protrude more than 200mm from the roof surface and do not face a highway on a listed building. Conservation areas and listed buildings may have additional restrictions. Always check with your local authority.

Modern solar panels typically come with a 25-year performance warranty guaranteeing at least 80% of original output. Many panels continue working effectively for 30-40 years. Inverters typically need replacing after 10-15 years at a cost of £500-£1,000. Panels require minimal maintenance beyond occasional cleaning.

Research suggests solar panels can increase property value by 1-4% in the UK. A 2023 study found homes with solar panels sold for an average of £1,800 more per kW installed. The exact increase depends on system size, property type and local market conditions. Some estate agents actively market solar as a selling point.