FAQs

Savings vary depending on your energy usage and system size, but most homeowners significantly reduce their electricity bills and protect themselves from rising energy costs.

Yes. Solar panels still generate electricity in cloudy conditions, just at a reduced output compared to direct sunlight.

Most residential solar installations are completed within 1–2 days, depending on the system size and property type.

In most cases, solar panel installations fall under permitted development and do not require planning permission. We'll confirm this during your survey.

Solar panels are designed to last 25–30 years, with many systems continuing to perform well beyond that timeframe.

Excess energy can be stored in a battery (if installed) or exported back to the grid for potential financial returns.

Mostly they are not — but the question is asked often enough to deserve a straight answer. Where panels do come off, it is usually one of three things, and none of them is "solar stopped working". The commonest by far is a roof replacement: the panels are removed and refitted around the roofing work. The second is a legacy rent-a-roof or leased-panel arrangement from the Feed-in Tariff era, where the homeowner never owned the system and the lease complicates a house sale — an ownership problem, not a technology one. The third is age: an inverter typically needs replacing somewhere around year ten to twelve, and an owner who was mis-sold on savings that never materialised may decide not to spend again. We would rather you knew all three before you buy than after.

It is not an official rule. There is no 20% rule in UK planning law, in MCS certification or in any government standard — it is a rule of thumb that circulates online, and it is worth knowing that people mean two different things by it. Sometimes it means sizing: design the system with roughly a fifth of headroom, because real output is trimmed by cloud, shading, dirt, panel degradation and inverter losses, so a system sized exactly to your consumption on paper will fall short in practice. Sometimes it means maintenance: if output drops around 20% below what the system should be producing for the season, something is worth investigating. Both are reasonable instincts. Neither is a substitute for modelling your actual roof, which is what a survey does.

Also not an official rule, and confusingly it is used for three unrelated things. The first is self-consumption: a rough claim that about a third of what you generate gets used in the home and the rest is exported — a starting assumption, not a fact about your house, and one you can move a long way with a battery or by shifting usage into daylight. The second is inverter oversizing: fitting panel capacity up to about a third above the inverter rating, on the basis that panels rarely hit their peak, so a 5kW inverter might carry around 6.6kW of panels. The third is physics: a conventional single-junction silicon cell cannot convert much more than a third of the sunlight hitting it into electricity — the Shockley–Queisser limit — which is why real-world panel efficiencies sit in the low-to-mid twenties. If someone quotes you "the 33% rule" as though it settles something, ask which of the three they mean.

We would rather point you at the source than paraphrase someone else's view. MoneySavingExpert, the consumer site Martin Lewis founded, publishes its own free guide to solar panels covering costs, payback and the Smart Export Guarantee, and it is a genuinely useful second opinion to read alongside any quote — including ours. What we will say is that the questions MSE tells people to ask are the right ones: what does it actually cost installed, how much of the generation will you use yourself rather than export, what happens when the inverter needs replacing, and is the installer still going to exist in year eight. If a quote cannot answer those four plainly, that tells you something.

Very little. Solar panels have no moving parts, and at the pitch of a typical UK roof, rainfall keeps them reasonably clean on its own — the Energy Saving Trust describes solar PV as needing little maintenance. It is sensible to glance at your monitoring app now and then: a sustained drop in generation that does not match the weather is the main sign something needs attention. An occasional professional clean can help if soiling is visible — bird droppings, lichen, or dust from nearby trees and fields. The component most likely to need work during the system’s life is the inverter rather than the panels themselves, which is covered in the next answer.

It is optional, but worth considering if pigeons are active in your area. The gap between the panels and the roof is sheltered, warm and safe from predators, which makes it an attractive nesting spot. Nesting birds bring droppings that soil the panels and reduce output, debris that can block airflow, and occasionally pecked cabling. Bird-proofing is a mesh fitted around the perimeter of the array, clipped to the panel frames so nothing is drilled through your roof. Having it fitted at installation time is straightforward; retrofitting later means paying for scaffolding or roof access all over again, which usually costs more than the mesh itself. Ask at the survey stage whether your property is in an area where it is worth doing.

The inverter converts the DC electricity your panels generate into the AC electricity your home and the grid use — every solar system has one, and it works all day, every day. Typical manufacturer warranties on inverters run from around 5 to 12 years depending on the brand and model, and hybrid inverters (which also manage a battery) sit in the same range. Because the panels themselves are designed to last 25 to 30 years, it is realistic to plan for the possibility of one inverter replacement during the system’s lifetime. Your monitoring app usually flags inverter faults early. When comparing quotes, check the inverter warranty length in writing rather than assuming it matches the panels — the two are covered separately.

You do not need to arrange anything yourself, but your local Distribution Network Operator (DNO) — the company that runs the wires in your area, separate from your supplier — must be told about any generation connected to the grid. The rules, set by the Energy Networks Association, come in two forms. Systems up to 3.68kW per phase fall under G98: they can be installed first and notified within 28 days of commissioning. Larger systems fall under G99 and need the DNO’s approval before installation starts, which can add lead time to bigger projects. Submitting the right paperwork is the installer’s job as part of the MCS process, so a certified installer handles both routes and tells you which applies to your system.

None at the moment. Installing energy-saving materials in residential properties in Great Britain — including solar panels, and battery storage whether fitted with panels or on its own — carries 0% VAT until 31 March 2027, under HMRC’s VAT notice 708/6. From 1 April 2027 the rate is due to revert to the reduced rate of 5%, not the full 20%. The zero rate covers the whole installed job: equipment, labour and scaffolding billed together by your installer. It does not apply to equipment you buy separately and fit yourself. If you are weighing up timing, the current window is a meaningful saving on a typical system compared with the position after March 2027.

Off-street parking — a driveway or an allocated space — is the main practical requirement, and it is also a condition of the current grants. The charger needs its own dedicated circuit from your consumer unit, and since June 2022 every home chargepoint sold in Great Britain must have smart functionality built in, so charging can be scheduled for cheaper off-peak hours. Your installer notifies the network operator and self-certifies the electrical work under a competent person scheme. On grants: owners of single-occupancy houses are no longer eligible, but the EV chargepoint grant for flat owner-occupiers and renters pays 75% of the cost up to £500 per socket — raised from £350 on 1 April 2026 — and runs until 31 March 2027.