Solar panels UK: Definition, installation and efficiency

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solar panels

As we all become more conscious of the environment and climate change, more and more people are looking for sources of green energy to reduce our use of the world’s natural resources. Solar energy is one way that many households and businesses in the UK are turning to. In this guide, we’ll look at everything to do with solar panels - how they work, how efficient they are, and how much they cost.

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How do solar panels work?

Solar panels - also known as pv solar panels or photovoltaic solar panels - are made up of cells that use semi-conducting materials, such as silicon. Between each layer of semi-conducting cells is a layer of photovoltaic cells, and it is these that turn the sun’s energy into electricity.

When light shines on the solar panel, photons from the sun’s light create an electric field. Solar panels generate direct current (DC) electricity whereas in our homes and businesses across the country we use alternate current (AC) to power our appliances. That is why an inverter is needed to convert DC to AC. The electricity generated from the solar panels can then be used to feed into the National Grid or power our homes.

How efficient are solar panels?Solar panels don't need direct sunlight to work - they also create electricity on cloudy days. However, the more sunlight there is, the more electricity they will generate. In terms of efficiency, according to Solar Guide, solar panels are about 10 - 20% efficient, meaning that of all the light received, 10 - 20% will end up being generated into electricity.

Types of solar panels

types of solar panels

If you are thinking of installing solar panels, you should be aware there are two main types on the market: monocrystalline and polycrystalline solar panels. Both are made up of the same materials, but have a slightly different configuration. This can affect things such as cost and efficiency.

  • The monocrystalline panel: as its name suggests, it consists of a single silicon crystal. Due to the complexity of its manufacture, the monocrystalline panel is generally more expensive. It also has better efficiency (between 16 and 24%) and higher power (between 300 and 375 Wp).
  • The polycrystalline panel: conversely, it is made up of several silicon crystals. It is less expensive, but also has a lower efficiency (between 14 and 18%) and a lower power (between 250 and 275 Wp).

The choice of the type of solar panels depends a lot on the power of the installation that is needed, as well as the surface available for the installation of the panels. Their installation can have a fairly substantial cost, but solar energy represents a profitable investment, without forgetting that it is clean, free and inexhaustible.

What is solar thermal energy?By installing thermal solar panels, it is possible to take advantage of solar thermal energy. Unlike photovoltaic solar energy which directly converts part of the sun's electromagnetic radiation into electricity, solar thermal energy converts the sun's heat.

How to install solar panels?

There are many companies across the UK that specialise in the installation of solar panels, if you decide you would like to install roof solar panels. However, many people opt to do it themselves. If you go down that route, there are a number of things you should be aware of first:

  1. Check that amateur installation is permitted by both your utility supplier and your local building authority;
  2. Ensure you have the standard roof tiles to install the pv panels - asphalt shingles, standing-seam metal, wood shingles, and a standard flat roof. If you don’t, it’s not the end of the world. You should check with roofing specialist before you start though;
  3. Make sure your homeowner’s association (if you have one) allows the installation of solar panels;
  4. Be prepared for physical work. Depending on the amount of panels you need to install, you could be working on a roof for a couple of days. Always make sure you take appropriate safety measures.

Portable solar panels: What can you use them for?

As well as solar panels for homes, you can also try using a portable solar panel, popular with people who want to use solar power for camping or use a solar panel for their caravan instead of relying on a generator.

These types of solar panels are not as big as permanent fixtures, and will generate less electricity - normally around the 100 watt mark. The advantage of portable solar panels is that you can take advantage of the sun’s energy when you are travelling off the beaten track. Portable solar panels and chargers can be used to power numerous appliances, including your mobile phone if you are out hiking and running out of battery.

In addition to their versatility, they are often very simple to use, and include unique design features, such as being foldable.

How much do solar panels cost?

While the cost of installing solar panels has reduced in recent years, they are still a considered purchase. The initial outlay can be quite expensive and the return on investment can take up to 15 years, so you should think carefully before deciding.

According to the Solar Guide, it can cost around £6,000 – £7,000 to install solar panels on the average UK household. The cost of installing solar panels does vary depending on the size of the house and the amount of electricity needed to be generated. The table below is a guide as to how much it costs to install, bearing in mind the average 3-bed property in the UK will need 3-4 kw of power.

The cost of installing solar panels in the UK
Solar panel power Cost
1 kw £1,840
2 kw £3,680
3 kw £5,520
4 kw £6,040


Solar panels grants: What help is available?There are currently no grants available for installing solar panels in the UK. There used to be between 2013 and 2015 before the Government’s Green Deal was scrapped. However, homeowners can make money under the Small Export Guarantee, a government-backed initiative in which large energy suppliers with more than 150,000 customers pay homeowners for any solar-generated electricity they send back to the National Grid.

Advantages of solar panels

By deciding to use solar panels, you will be helping reduce carbon emissions by not relying on fossil fuels. There are, however, numerous other advantages to using solar panels, including:

advantages of solar panels
  • Saving money on energy bills: You could save up to £220 per year on your electricity bills, according to The amount you are able to save depends on two main factors - how much energy your solar panels produce, and how much electricity you use. One option is to use a solar panel with battery storage to save the electricity generated when you are out of your house;
  • Get cash back from generating electricity: Most homes with solar panels in the UK actually generate more electricity than they need. The government has in place the Small Export Guarantee in which you can get money for generating electricity and connecting it into the National Grid;
  • Environmental impact: Solar panels drastically reduce the amount of carbon emissions generated by UK households. The Energy Savings Trust estimates that the average household can reduce their carbon emissions by 1.6 tonnes every year thanks to solar panels;
  • Low maintenance: Once installed, solar panels are very easy to maintain and at very low cost too. You don’t need to keep an eye on them 24-hours a day. Indeed, most just need to be kept clean from time-to-time. The majority of solar panels come with a 25-year warranty, so if anything does go wrong, you should be covered anyway.

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Disadvantages of solar panels

As with anything, there are of course some disadvantages of solar panels. Some of the main cons are:

  • They take up lots of space: The standard solar panel is around 2 m2. The more electricity you want to generate, the more panels you’ll need - so you may need to have a large roof;
  • They are dependent on the weather: As mentioned previously, the more sunlight they receive, the more electricity solar panels generate. The UK isn’t famous for its sunny weather, so homeowners who install solar panels, while still generating electricity on cloudy days, will find they need to rely on the grid too;
  • Long return on investment: On average, UK households will see their return on investment in around 15 years after installation - so you will need to be patient.

Find all our other practical guides on the protection of the environment and the development of green energies!