Category - Solar
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Will Scholfield, Engineer

15 Sep : Updated 9 Apr ● 6 min read

How do solar panels work?

If you're ready to embrace a greener future, take charge of your energy consumption, and leave a lighter footprint on our planet then you’ll likely be exploring the pros and cons of installing solar panels. Even more so, since technological advancements have seen solar panels becoming increasingly affordable for UK homeowners. 

But, before making the investment into solar panels, you’ll need to have a clear understanding of how they work. This is so you can determine what maintenance is required and how you can best utilise them to meet your property’s electricity requirements.

In this guide, we’ll take things right back to basics and explain how solar panels work in simple, straightforward terms, empowering you with all the information you need to decide if going solar is right for you and your home.

How do solar panels generate electricity?

Solar panels are a source of renewable energy that, when well maintained and looked after, can see a return on investment (ROI) anywhere between 8-12 years. 

Also known as photovoltaic (PV) panels, solar panels use the photovoltaic effect* to turn sunlight into electricity. And they work as follows: 

  1. When the sun shines on a solar panel, they absorb energy (or photons**). This energy generates electricity that moves to an internal electrical field in the cell, resulting in the flow of electricity and thus, providing your home with power. 
  2. An electric field is formed in the solar cells by inserting a layer of negatively charged material on one side of the cell and a layer of positively charged material on the other. This electric field aids in the separation of newly freed electrons from the positively charged "holes" left behind.
  3. The freed electrons are forced to migrate towards the negatively charged layer of the solar cell due to the electric field, resulting in a flow of electrons or an electric current. This movement of electrons is known as electricity.
  4. PV cells on the panels convert light into direct current (DC) electricity. The current passes into an inverter, which converts it to usable alternating current (AC). The current is routed through a metre and then into the consumer unit in your home.

*The photovoltaic effect is the process by which PV cells convert absorbed sunlight energy into electricity.

**Photons when referring to anything solar are “tiny packets of light” that originate in the sun’s core. They are produced when hydrogen cores crash together to make helium. 

What are some of the advantages of solar energy?

Renewable energy source

One of the most significant benefits of solar energy is its renewable nature. The sun is a rich source of energy with practically endless capacity. Unlike scarce and declining fossil resources, solar energy provides a long-term answer to satisfying our energy needs.

Environmentally friendly

Solar energy is a clean energy source that emits no damaging pollutants or greenhouse gases. Whereas, traditional energy sources like coal and natural gas pollute the air and contribute significantly to climate change.

Being energy independent

Households, communities, and even countries can minimise their dependency on imported fossil fuels by embracing solar energy. Solar power provides energy independence by allowing consumers to generate their own electricity, and reducing their reliance on shifts in fuel prices or geopolitical concerns.

Saving money

Whilst the initial investment into renewable energy is substantial, solar energy provides long-term cost benefits. These include, being low-maintenance, having a longer life-span than traditional energy sources and, overall, saving you money on your bills.  

Variety of applications

Solar energy can be used for a variety of purposes, ranging from small-scale home systems to large-scale power facilities. It has the potential to power homes, companies, and perhaps entire cities. 

Do solar panels work on cloudy days?

Yes, even on cloudy or overcast days, solar panels can generate electricity. This is because some, albeit not all, of the sun’s solar energy will be able to pass through any cloud cover and onto the panels.

Solar panels can generate power from either direct or indirect sunlight, though they are more effective under direct sunlight. They will continue to function even if light is deflected or partially covered by clouds and any unpleasant weather, such as rain is good - because it helps your panels run more efficiently by cleaning away dust and debris.

Does it need to be hot for solar panels to work?

Solar panels do not require hot temperatures to operate well. In fact, too much heat can reduce their efficiency. Solar panels are mostly built of silicon, a semiconductor with a negative temperature coefficient. This means that when the temperature rises, the silicon's electrical conductivity decreases. 

The temperature coefficient for most solar panels ranges between - 0.3% and - 0.5% per °C. For example, if a solar panel has a temperature coefficient of - 0.4% per °C, its efficiency drops by 0.4% for every 1°C increase in temperature. As a result, a panel working at 40°C may see a 12% efficiency reduction relative to its rated performance.

As a result, a hotter environment can reduce the panel's energy output.

Whilst they still work, there are a few steps you can take to ensure you are getting the most out of your panels when the sun hasn’t got his hat on: 

  • Ensuring adequate airflow around the solar panels by using proper ventilation aids in heat depletion and temperature control, resulting in increased performance
  • Mounting panels with enough space between them and the mounting surface can aid with air circulation and minimise heat buildup
  • Adjusting the tilt and angle of the panels to maximise exposure to sunlight while minimising heat absorption can improve overall efficiency
  • Investing in high-quality panels with lower temperature coefficients can help to reduce efficiency loss in hot weather

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Can I install solar panels?

If you’re looking to add solar panels to your home, then you should leave it to the professional rather than attempting to install them yourself, as it is an intricate job that requires skill, knowledge and experience. What’s more, there are a number of technical aspects that not every DIYer has, such as electrician training.

To replace traditional energy sources, an average-sized home in the UK (2,480 square feet) will require between 12 and 20 full-sized solar panels. Having said that, the exact amount of solar panels required for your home is determined by a number of other factors.

In most cases, with the help of an experienced professional, you can install solar panels on your property. However, there are some instances when solar panels cannot be installed. These include: 

  • Having a north-facing roof
  • Having little to no roof space
  • Having a lot of shade over your roof
  • Living in a listed building 

How much does it cost to install solar panels?

The cost of installing solar panels depends on a number of factors, including the size of your system, the type of panels you select, and your location. Without factoring in the cost of labour and installation, each panel could cost you anywhere between £150 and £400 per panel. 

Before any applicable discounts or Government grants, a typical 4 kW solar panel installation can cost upwards of £8,000. It's important to remember that these prices are estimates and can vary, so we recommend acquiring quotes from a range of installers to get the most exact pricing for your needs.

With BOXT, our solar panel installation service is unrivalled - simply enter your postcode to get started. 

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