Questions & answers

How long do solar PV systems tend to last? And how much maintenance do they require?

Solar panels are built to withstand the elements, and should last for a long time with little or no maintenance. Most reputable manufacturers offer a 25 year guarantee, but many manufacturers also offer performance guarantees. As panels age, the amount of power they generate reduces. A manufacturers' performance guarantee will ensure that if the power drops below a certain level, you'll be entitled to repair or replacement panels.

Do solar PV panels work in cold weather conditions? Will the energy they generate drop during the winter?

Yes, they do work in cold weather. In fact, many people are unaware that PV panels are actually at their most efficient in lower temperatures. Although it seems obvious, it's easy to forget that PV panels only generate electricity from light- not heat. In more extreme conditions, light can become obstructed by a buildup of snow or ice on the panels. However this rarely causes a long term problem as, coupled with the incline on most roofs, the panels usually give off enough heat to thaw most of the buildup without additional maintenance being required.

Do PV panels produce electricity in all weather conditions, such as in a cloudy or overcast day?

The simple answer is "yes". PV panels produce electricity in almost all weather conditions. Solar panels don't just absorb the visible parts of the electromagnetic spectrum, but also the parts that the human eye can't detect, and which also pass through clouds more easily. That said, the output would be noticeably lower on a cloudy day than it would be on a clear sunny day.

Is it necessary to seek planning permission before installing rooftop solar panels on a residential property?

So long as your property is not a listing building, we're pleased to say that you do not need planning permission or approval from any authority before going ahead and installing solar panels on your roof. There are however a few government guidelines that you should adhere to:

  • The panels should be positioned as much is practical in order to minimise the visual impact on the building;
  • When no longer required or being used to generate electricity, panels should be removed as soon as possible;
  • Panels should project no more than 200mm from the surface of the roof.

We've already decided to install solar panels, but have only received combined quotes for the supply of panels and components, and the installation of the system. Is it cheaper to buy the panels ourselves and contract an installer separately?

This is a good question and one which we hear often. We usually advice that the average installation cost for a family sized home is somewhere between £1500 and £3000. Often installation companies will add a slight markup to the price of panels they supply; however as the buy in bulk, they usually command cheaper prices than would be available to the individual buyer. We would recommend that unless you get a fantastic deal on panels, it's probably best to stick with the installation company.

Is my home suitable for a domestic PV system?

The vast majority of UK homes are suitable for solar PV systems, both in urban and rural settings. Whilst the amount of energy received from the Sun varies across the country, it is not by a large amount. The most important thing to watch out for is shade created by trees, buildings and other obstructions lying to the south. Whilst there are some small differences in the installation procedure of different types of roof, only houses with thatched roofs are truly problematic.

Where on my house will the solar panels be installed?

As the UK is in the Northern Hemisphere, a south facing roof will receive the most sunlight. The perfect house for solar panels has a roof orientated between south west and south east, with about 30° of slope and no shading. For homes that do not have a south-facing roof, east-west splits are quite common and produce about 85% of the energy a south-facing roof will.

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