Find a Solar Panel Installer you can trust in Brackley.

The lifetime of a solar panel depends on its quality and age. Generally, the older a solar panel gets, the less efficient it becomes. The majority of modern solar panels come with 20-30 year warranties, which means that they’ll stay at a good efficiency level for at least this long. Some panels can stay efficient for as long as 40 years, while others won’t last this long.

Solar panels are made up of photovoltaic (PV) cells. These cells are made from silicon semiconductors, which absorb sunlight and convert it into electricity.

There are three main types of PV cell: monocrystalline solar cells, polycrystalline solar cells, and thin film solar cells. Monocrystalline cells are usually the most efficient and expensive, and thin film solar cells are the cheapest and least efficient. These are all made from silicone, but are manufactured in different ways.

Solar PV panels work by converting sunlight into electricity. They’re made up of photovoltaic cells, which take in the sun’s rays and turn it into direct current (DC) electricity. The current is then channelled into an inverter, which converts it to alternating current (AC).

Once converted to AC, the electricity is ready to use. It’s fed through a meter and into your property’s consumer unit, and is automatically used to power appliances and heating systems. Your system will automatically switch between your solar electricity supply and the national grid, and export any solar electricity you don’t use to the national grid.

It’s important to get the right size solar panel system for your commercial property. Solar panels are usually installed on pitched roofs, although they can be fitted on stands on the ground if you have some unused outdoor space. The more panels you install, the more power you’ll generate, but there’s no point buying more panels than you have space for.

Solar panel system sizes are measured in kW. 4-10kW solar panel systems are usually too big for domestic properties but are ideal for smaller commercial properties. Here’s an idea of how many panels and space you’ll need for a few different system sizes:

System size, Number of panels, Area required (approximate)

4kW, 16, 23m²

6kW, 24, 35m²

8kW, 32, 46m²

10kw, 40, 58m²

Bear in mind that solar panels can’t be less than 30cm away from a roof edge, so you’ll need more space than the area that the panels take up.

How long your solar panels will last depends on their age and quality. Most modern solar panels have 20-30 year warranties, but this doesn’t mean that they’ll stop working at this point. Many will stay at a good efficiency level for up to 40 years, while others will start to decline earlier.

There are a few trusted companies in the UK that make solar panels. While there are other solar thermal panels out there that are made by Chinese and American companies, we’ll focus on the brands with a longstanding presence in the UK since these are the panels MCS-registered solar companies are likely to recommend to you.

Viessmann, Worcester Bosch, Solar UK and Dimplex make some of the best solar thermal panels in the UK. Dimplex and Viessmann offer both flat plate and evacuated tube solar panels, while Solar UK only offers evacuated tubes. Worcester Bosch’s Greenskies range are all flat plate collectors. Viessmann’s panels come with a 5-year warranty, while Worcester Bosch and Dimplex offer extensive 10-year warranties. However, Solar UK offer a comprehensive 25-year warranty and guarantee that the panels will deliver the same level of performance for 25 years!

We’d recommend choosing evacuated tube solar thermal panels because they are the most efficient. While there won’t be much difference between evacuated tubes and flat plates in the summer, in the winter evacuated tubes are much better at taking heat from the sun than flat plates. Since our winters are long and cold with few daylight hours, we think it makes sense to go with evacuated tubes. However, if your priority is looks over maximising efficiency, you might want to choose flat plate collectors since they sit flat on the roof and look more like solar PV panels, whereas the evacuated tubes will stick out.