The questions homeowners actually ask

Yes — though output is reduced. Solar panels respond to light, not heat or direct sunshine. Diffuse light on an overcast day still generates electricity. The UK's solar resource is lower than southern Europe, but it's not negligible. The important figure is annual irradiance for your location, which is available from tools like the PVGIS database maintained by the European Commission.

Both use silicon, but the crystal structure differs. Monocrystalline panels are made from a single silicon crystal, which gives electrons more room to move — translating to higher efficiency. They tend to be more expensive per panel but produce more power per square metre. Polycrystalline panels use multiple silicon fragments melted together. They're typically less efficient but have historically been cheaper. Most modern residential installations use monocrystalline, including the newer PERC and TOPCon variants.

Solar panels produce direct current (DC) electricity. Your home runs on alternating current (AC). The inverter converts one to the other. It also handles grid synchronisation, safety disconnection, and — in modern units — monitoring and data logging. String inverters handle the whole array centrally. Microinverters attach to each panel individually, which helps in shading situations but adds cost. Power optimisers are a middle ground — they optimise at panel level but still use a central inverter for the AC conversion.

Most manufacturers offer a 25-year performance warranty, guaranteeing output above a certain threshold at that point — typically around 80% of original rated output. Actual panel lifespan often extends beyond 30 years, though output continues to degrade slowly. Inverters generally have a shorter lifespan and may need replacing once or twice over the panel lifetime. This is worth factoring in when comparing total system costs.

A proper site survey should include a physical inspection of your roof — checking condition, pitch, and orientation. The installer should assess potential shading from chimneys, neighbouring buildings, and trees at different times of day and year. They should also look at your existing electrical installation, fuse box capacity, and meter setup. A survey conducted only via satellite imagery and online tools is not sufficient for an accurate design.

MCS stands for Microgeneration Certification Scheme. It's an industry standard for small-scale renewable energy technology and installation. Using an MCS-certified installer is a requirement for accessing the Smart Export Guarantee — the scheme through which energy suppliers pay for electricity you export to the grid. It also provides a level of quality assurance and access to a complaints procedure if things go wrong. You can verify an installer's certification on the MCS website.

In most cases, no. Solar panels on a residential roof in England typically fall under permitted development rights, meaning no planning application is required. Exceptions apply if your property is listed, if you're in a conservation area, or if the installation would protrude significantly above the roofline. Scotland and Wales have their own planning rules which are broadly similar. If in any doubt, your local planning authority can confirm before you commit to anything.

It depends on your situation. Battery storage allows you to use solar electricity generated during the day at times when you'd otherwise import from the grid — evenings, for example. Whether this makes sense financially depends on your consumption pattern, the size of your solar array, your electricity tariff, and the cost of the battery. It's worth modelling your own usage before assuming storage is a good addition. Some households benefit significantly; others see modest returns.

Battery manufacturers quote a rated (or nominal) capacity — the total energy the battery can store. Usable capacity is the amount you can actually draw on in normal operation. Lithium-ion batteries are typically not discharged to zero, as doing so repeatedly degrades the battery faster. Usable capacity is usually around 80-90% of rated capacity, though this varies by product. Always compare usable capacity figures when evaluating storage products, not just the headline number.

The Smart Export Guarantee (SEG) is a UK government scheme that requires larger energy suppliers to offer a tariff for electricity exported to the grid by small-scale renewable generators. The rate is set by each supplier and changes over time — it's not a fixed government rate. You need a smart meter and an MCS-certified installation to participate. Comparing SEG rates across suppliers is worth doing, as they vary.

Yes. You should inform your energy supplier when you install a solar system. This is required for grid connection notification and for participating in export tariff schemes. Your installer should handle the DNO (Distribution Network Operator) notification for systems up to a certain size, but it's worth confirming this is included in their service. Larger systems may require a more formal grid connection application process.