Solar Panels UK: 20 Most Common Questions Answered

25-30 years for the panels themselves. Inverters typically last 12-15 years and will need replacing once. Batteries (if fitted) last 10-12 years. The MCS warranty for workmanship is 10 years minimum. A well-installed system should still be generating at 80%+ of original capacity after 25 years.

Yes. Panels generate electricity from daylight, not direct sunlight. On a typical overcast UK day, you'll generate 10-25% of your peak capacity. This is why UK solar still makes financial sense — you're generating something most days of the year, not just sunny ones.

For most homes in England and Wales, no. Solar panels are covered by permitted development rights. Exceptions include listed buildings, conservation areas, and some flats. Your MCS installer will check this as part of their pre-installation survey. See our full guide on planning permission for details.

Solar PV (photovoltaic) panels generate electricity from sunlight — this is what SolarFoundry installs. Solar thermal uses sunlight to heat water directly and is a separate, older technology. The SolarFoundry calculator and pricing covers solar PV only.

A standard 400W panel is roughly 1.7m x 1.0m. A typical 4kW system (10 panels) needs approximately 17m² of usable roof space. South-facing roofs are ideal. Allow for shading from chimneys, skylights, and neighbouring buildings when assessing available space.

South-facing roofs generate the most electricity — typically 800-950 kWh per kWp per year in the UK. South-west and south-east face are also excellent (10-15% less generation). East and west-facing roofs generate about 20% less but are still viable, especially with a battery. North-facing roofs are not suitable.

You don't need permission from your energy supplier. However, you should register for the Smart Export Guarantee (SEG) with an energy supplier to get paid for electricity you export to the grid. This requires a smart meter and your MCS installation certificate.

MCS (Microgeneration Certification Scheme) is the quality standard for small-scale renewable energy installations in the UK. MCS certification is required to: (a) register for the Smart Export Guarantee, (b) access any government-supported schemes, and (c) comply with Building Regulations. SolarFoundry only works with MCS-certified installers — always ask for your installer's MCS number before signing a contract.

The SEG is a government-mandated scheme requiring licensed energy suppliers to pay you for electricity you export to the grid. Best rate in 2026: Octopus Energy at 7.9p/kWh. You receive payment based on how much you export (measured by your smart meter). See our SEG rates guide for how to maximise your earnings.

For a 4kW system in southern England (no battery): approximately £600-700/year in 2026, based on 35% self-consumption at 24.5p/kWh import rate plus export earnings. With a 5kWh battery (75% self-consumption): approximately £850-950/year. Use our instant quote calculator for a calculation based on your actual postcode and usage.

Your home stays connected to the national grid. When your panels aren't generating enough, your home draws from the grid as normal. With a battery, you can use stored daytime generation after dark. There is no interruption to your electricity supply.

Yes. Retrofit battery installation is possible with most modern inverters. It does cost slightly more than installing battery and solar together (roughly £200-500 extra for the additional installation work). Compatibility between your existing inverter and your chosen battery must be checked. See our battery storage guide.

Studies suggest solar panels add 2-4% to residential property values in the UK. The key factor is whether the system has a valid MCS certificate (which transfers to the new owner). A solar home with a documented track record of generation data and a valid warranty is attractive to buyers who are energy-aware.

Very little. Annual cleaning (can be done with a hose or by a window cleaner) keeps panels at peak efficiency. Inverters typically have remote monitoring systems that alert you to faults. A professional check every 3-5 years is recommended. Panels with heavy soiling from bird droppings lose up to 5% of generation.

Three separate warranties: (1) Product warranty: 10-15 years covering manufacturing defects. (2) Performance warranty: 25-30 years guaranteeing minimum output (typically 80% after 25 years). (3) Workmanship warranty: 10 years minimum (required by MCS standards). All SolarFoundry installations include a full 10-year workmanship guarantee.

For a typical 4kW system in southern England: 9-12 years without battery, 12-15 years with battery. In Scotland: 11-14 years (lower yield). Payback improves with: higher electricity bills, south-facing roof, smart tariff arbitrage, and battery storage combined with Octopus Agile. After payback, the system generates essentially free electricity for a further 15-20 years.

Yes. Flat-roof systems use angled mounting frames to tilt panels at 10-30 degrees for optimal generation. These are standard installations for MCS-certified installers. The cost is marginally higher than a pitched-roof installation due to the mounting system. Generation is slightly lower than a south-facing pitched roof but still excellent.

The main financial benefit is 0% VAT on solar and battery installations — valid until March 2027, worth approximately £350-700 on a typical system. Low-income households may qualify for funded solar through ECO4. The Warm Homes Plan is expanding but not yet available to private homeowners. For most homeowners, solar is full-price — but it still pays back. See our grants guide for full details.

Solar panels become a fixture of the property and transfer to the new owner. Your solicitor will handle the transfer of MCS documentation as part of the conveyancing process. The new owner can register for the SEG using the original MCS certificate. Solar panels are increasingly seen as a selling point rather than a complication.

Use our instant quote calculator at solarfoundry.co.uk/quote.html. Enter your postcode, property type, and electricity usage — you'll get an instant installed price within seconds, with no pushy salesperson. If you're ready to proceed, submit a quote request and Jake will follow up within 24 hours.