Secure Payments

Securely processed by Sagepay

Frequently asked questions about solar panels

With an increased focus on improving carbon emissions, reducing energy consumption and reducing our impact on the environment, considering opting for solar panels on your latest project has never been more popular. However, there are still a number of questions regarding solar panels that are commonly asked before making the decision to install solar panels, so we’ve put together a quick guide.

Table of Contents

1. How do solar panels work?
2. How long do solar panels last?
3. How many solar panels do I need?
4. How much are solar panels in the UK?

How do solar panels work?

Solar panels generate energy to power electrical appliances within your home, or to heat the water in your home, using sunlight. This conversion of sunlight into electrical energy is undertaken by photovoltaic cells.

A photovoltaic cell consists of two thin layers of silicon crystal. The top layer of silicon has been treated to destabilise the atoms within it, by ensuring each atom has one too many electrons, whilst the bottom layer has also been treated to ensure each atom doesn’t have enough electrons. Once the cell is exposed to light, the electrons from the top have enough energy to move down to the second layer. This creates a current, which when connected to two conducting materials either side, creates electricity.

Before the electricity is able to be used, it must be converted from DC to AC (direct current to alternating current). This is done via an inverter.

How long do solar panels last?

One question that often comes up when considering installing solar panels is how long do solar panels last? Solar panels can sometimes be a significant investment, so it is always worth knowing for how long they will be working and providing a form of return on investment.

There is not one single figure for the lifespan of a solar panel, as there are a number of different brands, different types of cell and different solar panel systems. However, most solar panels will come with a warrantee of around 25 years, but they will last for even longer. The estimated lifespan does not mean that the product will cease to work after the given time, but that you may experience a reduction in productivity – they can continue to work for several more years.

How many solar panels do I need (UK)?

The number of solar panels you need depends on a number of different factors. From the amount you’re looking to spend, to the amount of electricity you are hoping to replace, to your current electricity bills, and even the space you have available, there is a lot to consider, and there is no single answer to how many solar panels you’ll require.

To work out roughly how many solar panels you’ll require, complete the following steps:

1. Calculate your daily electricity usage

Use previous electricity bills to find out the average amount of electricity used in kWh, and divide by 30 if billed monthly, or 90 if billed quarterly.
Secondly, work out how many hours of sunlight your home gets. Monthly averages of daily sunlight hours can be found by searching on the internet, and then take an average of those figures to find out the average number of sunshine hours per day.

2. Calculate the electrical output of the specific solar panels you are considering.

This depends on the wattage of the solar panel, which can be anything from 320W or less to 4kW and more. Then multiply average hours of sunshine by the wattage of the solar panel. One of the most common solar panel wattages is 500W, and an average home in the UK will get approx. 4 hours of sunshine, so a 500W solar panel would produce 2kWh of electricity a day.

3. Work out how many solar panels are required

Use this information you have calculated so far to work out how many solar panels would be required to provide all of the home’s electricity usage – divide the daily electricity usage by the amount of electricity generated by the solar panel. For example if a home uses 10kWh a day of electricity, 20 500W solar panels would be required to provide all electricity (10000/500).

Other considerations

However, solar panels aren’t always used to power the entire home, but often to simply subsidise electricity bills, and provide some of the electricity required to power the home. For example, if you wanted to reduce your electricity bills by approximately 60%, using the above figures you’d require 12 solar panels.

If you’re unsure of how many solar panels you require, the manufacturers, suppliers or installers will often be more than happy to help with your calculations.

How much are solar panels?

Solar panels have a wide price range, depending on the number of solar panels, the specifications, and the electricity you’re looking to produce. Although the costs may seem high up front, it is always worth remembering that not only will you be reducing your contribution to carbon emissions and your impact on the environment, but also that it won’t take too long for them to start producing a return on investment.

Solar panels typically cost between £6000 and £9000, including installation, but as always, there are plenty of options outside of this price range. Here at Insulation Superstore we have a number of solar panels from Plug-In Solar and from the LG NeON range that provide between 320W and 4kW of electricity.

The Plug-In Solar kits are solar panels that can be mounted on roofs, or simply mounted on the ground. They are great options for outhouses, workshops and other installations, and can installed by DIY enthusiasts, or by professionals if preferred.

Alternatively, the LG solar panel kits have been engineered for modern aesthetics and high performance, and the comprehensive installation kits have everything required to meet Part L of building regulations, necessary for new builds, offices and other projects.

Feed in Tariff

Another thing to consider is the Feed in Tariff. The Feed in Tariff is a government scheme, which aims to encourage the uptake of renewable energy, and reduction in consumption of energy produced in traditional, carbon emitting ways. If your application is successful, you’ll receive a set amount per kWh of electricity produced, but you can also receive extra money by selling any excess energy produced back to the electricity supplier. This is a great scheme and provides another incentive for installing solar panels on your home or building, whilst reducing the overall cost, but the scheme is ending on 31st March 2019 – any applications made after this date will not be considered.

If you have any questions or queries regarding solar panels, their cost, where they can be used, or how many solar panels you need, feel free to call our team on 01752 692206 and they will be happy to help.


It seems you are running an older version of Internet Explorer. Our site does not support these old browsers as they do not house the technology that allows our site to be safe and secure.

If you wish to access our site please either upgrade your browser or download an alternative.