How Do Solar Panels Work? A Simple Guide (With Facts for Kids)

Written-by

Janet Richardson

Reviewed-by

Richard Burdett

Updated on

Feb 12, 2026

How Do Solar Panels Work? A Simple Guide (With Facts for Kids)

Welcome! In the video below you can get an animated and simplified look at how solar panels convert sunlight into usable electricity, for a bit more depth read on.

 

Solar panels work by harnessing the energy from the sun and converting it into electricity through a process known as the photovoltaic effect. 

You have probably seen a lot of solar panels recently, as more and more people are having them installed on their roofs. You may also have seen huge fields of solar panels when you have been out and about. However, do you know what they are or how they work? Take a look at this solar panel guide and find out just what solar power is! This article explains how solar panels work in simple terms, with helpful facts for younger readers too.

How a Solar Panel Works

The solar panels that are installed on the roof of a house capture energy from the sun. They take this energy and use it to provide the house with electricity (and, with solar thermal panels, hot water). Solar panels can even work on cloudy days when the sun isn’t very visible at all. Each panel is made up of a layer of silicon cells, a metal frame, a glass casing surrounded by a special film, and wiring. To make the most of the energy from the sun the panels are grouped together into “arrays” and placed on rooftops or in large outdoor spaces.

The solar cells also known as photovoltaic cells absorb sunlight during daylight hours. Solar cells use the sun’s light rather than its heat. When the sun shines on a solar cell, the cell turns the light energy into electricity. As a single solar cell will only make a little electricity, they are grouped together so that they can provide electricity for whole buildings. Of course, solar panels cannot provide a home with power at night, so most people still have to remain connected to the National Grid (this is where you get your electricity from). However, there are some advantages to staying connected to the National Grid, as you will see in this step-by-step guide on how solar power provides energy for your home. 

• The sun shines on the solar panels and the panels absorb the energy, creating direct current (DC) electricity. Within each solar cell is a thin semiconductor wafer consisting of two layers of silicon. One of these layers is positively charged and the other is negatively charged which forms an electric field. When light energy from the sun hits a photovoltaic cell, it stimulates the cell causing electrons to ‘come loose’ from atoms within the semiconductor wafer. Those loose electrons are set into motion by the electric field surrounding the wafer, and this motion creates the electrical current. 
• Because the direct current (or DC) is not the type of electricity that powers most homes it needs to be converted into alternating current (or AC) electricity. Fortunately, DC electricity can easily be changed into AC electricity by a gadget called an inverter. The electricity is fed into the solar inverter which converts the DC electricity into alternating current (AC) electricity. In modern solar power systems, one inverter can work for the entire system or individual microinverters can be attached behind the panels. 
• The AC electricity is then distributed within the home to power your appliances. It works in the same way as the electrical power generated through the grid by your electric utility company, so you don’t need to change anything within your home. 
• On cloudy days and during the night your solar panels may not be able to capture enough sunlight to use for energy. However, since you are still connected to your traditional power company, you can automatically draw additional electricity from the grid to make up for any solar shortages. The reverse can also happen, and your solar panels may collect surplus energy, more than is needed to operate your home, especially if there is no one at home during the day. Any power that your home does not need gets sent back or sold to the National Grid for others to use. In the UK, exported electricity may qualify for payment under the Smart Export Guarantee (SEG), depending on your supplier and tariff.

Having learned the basics about solar power you can only be amazed at how photovoltaic technology today can capture the huge power of the sun to operate our homes. It’s not quite rocket science, but it is an example of human ingenuity at its best. 
 

How do Solar Panels Work diagram:

Photovoltaic Cells

Photovoltaics has been around for a good few years now. Back in the late 1950s PV cells were almost exclusively used to power things like satellites. And many of us remember having calculators at school that didn’t need a battery because they were powered by the sun. The desire to harness that energy has been the Holy Grail of renewables for the last 30 to 40 years.

The great thing about solar cells is that they don’t need bright sunshine to work. They just require light and can produce electricity even on a cloudy day – which is great news here in the UK.

There are several types of photovoltaic cell used in solar panels UK. They are made from silicon, an excellent semi-conductor. These different cells vary in the efficiency of their electricity production, their purity and their cost. Put simply, the cells absorb the light from the sun and convert it to electricity. By placing a connection either end of the cell you can then collect that current and use it to power all your energy needs. Find out more about the different types of photovoltaic cells.  

The Solar Panels

The photovoltaic cells are bunched together into modules that make up a panel. In a typical solar panel, you will have two thin layers of silicon that have been treated in slightly different ways. The top layer, facing the sun, has atoms that are unstable so that when an energy source hits them, electrons fly off. The lower layer has a number of ‘gaps’ in the atoms that are in dire need of an electron or two.

When sunlight hits the top layer, electrons are energised and move through the material, creating an electrical current that can be captured through metal contacts and used as electricity.

Types of Solar Panel We are all familiar with the glass style solar panels we see on roofs around town. There are a number of different varieties now available, including ones that look like normal tiles. Find out more about the different types of solar panels on the specific page dedicated to this answer.

Converting the Electricity

How do solar panels work on a house UK? The current created in the solar panels by the excitation of electrons is called direct current or DC current. DC electricity is not suitable for running our household appliances or feeding into the National Grid. To be of any use at all, a conversion to AC electricity or alternating current is necessary. For this you need a box called an inverter. This usually sits outside your panel array, somewhere like the attic. The DC current enters it and emerges as AC and can be fed into your house. More on inverters here.

Efficiency of Solar Panels

If you want to buy solar panels for your home or business then there are a number of considerations to make that will have an effect on the efficiency of electricity production including the location and type of array. Efficiency of the photovoltaic cells: There are different types of cell that produce more or less energy depending on their size, thickness and purity. The purer kind tend to be more efficient and hence more expensive.

A South facing roof: To get the optimum energy production you need a South facing roof. This will ensure the panels catch more of the direct sunshine. That said, you can generally install east to west through south. 

Potential shade: Do you have trees surrounding your roof? Then you need to consider how much it will be in shade over the summer months. An oak tree may seem fine in winter when the branches are bare, but when it is in full bloom that may have an adverse effect on the amount of electricity you can produce.

Roof angle: Most installers of solar panels recommend an inclination of between 22 and 75 degrees to get the most out of the sunlight. The ideal angle will also depend where in the UK your house located. For a house in London the ideal roof or solar panel array angle is 51 degrees, while in Aberdeen that is 57. The ideal angle also changes slightly throughout the seasons, although most fixed UK systems perform well year-round without adjustment.

Size and number of panels: Of course, you will need to have enough room on your roof to cope with the right number of panels. There will need to be enough to provide all your energy needs. You will want to be able to produce a surplus for selling onto the National Grid. As a rule, higher purity, more expensive photovoltaic cells need less space than cheaper alternatives. It’s a question of getting the right balance between cost and efficiency and the space you must devote to the installation.

What are Solar farms?

Solar farms also known as solar parks or solar power plants are large areas of land that are covered with thousands of solar panels that generate lots of electricity. They are large-scale grid-connected photovoltaic power systems (PV systems). Some solar farms have fixed solar panels that always face in the same direction while others have moving panels that turn so that they always directly face the sun. This helps them to generate as much electricity as possible. 

Some modern solar farms include battery storage systems to store excess energy, although many still rely on the wider electricity grid to balance supply and demand.

Some large solar farms in the UK are now being developed alongside battery storage to help extend supply beyond daylight hours.

Agrivoltaics

The large areas of land taken up by solar farms can also be used for agriculture. A recent study found that the value of solar-generated electricity combined with shade-tolerant crop production created an over 30% increase in economic value from farms deploying agrivoltaics systems instead of conventional agriculture. 

Solar Battery Storage 

Solar batteries store the excess energy generated by your solar panels to power your home when the weather is gloomy, rainy or the sun has set. 

Solar batteries can be an alternative to feeding energy back to the grid as you can use the energy stored in the battery when you actually need it. Chemical reactions take place within the battery to store the surplus electricity as potential energy. Any solar power not used during daylight hours is captured by the solar panels and stored within the battery ready to be converted back into usable electricity for future use. 

The Advantages and Disadvantages of Solar Power

The advantages:

• Solar panels produce clean energy. They create no harmful gases, so they are very environmentally friendly.
• Solar panels help to reduce your carbon footprint. A carbon footprint is the total amount of greenhouse gases including carbon dioxide and methane that are generated by our actions. Reducing our carbon footprint helps the UK to reduce its overall carbon emissions. 
• Solar panels produce a completely renewable and inexhaustible source of energy as the sun’s energy is not going to run out for billions of years.
• Solar panels require little maintenance because there are no moving parts. Post-installation maintenance is similar to that of a normal electrical system with the addition of some periodic cleaning.  
• Solar panels are reliable. Sunlight is an energy source that can be used anywhere on the planet. Solar photovoltaics is a mature technology that has been developing since the last part of the twentieth century. Solar cell efficiency is improving all the time and is now over 20%. At the same time as, solar cells are becoming more efficient, they are also becoming cheaper making them increasingly more accessible and available. Many modern solar panels come with performance warranties of 20–25 years and can continue generating electricity beyond that period, although output gradually declines over time.
• Solar panels don’t produce any noise as there are no moving parts.
• If the sun is shining on your solar panels, you can use the energy for free, and so reduce your electricity bills.
• It is possible to make money from solar panels. Energy suppliers in the UK have to pay households for the renewable energy they export to the National Grid. This is achieved via the Smart Export Guarantee, a government-backed initiative. Energy suppliers set different rates for the electricity they buy thus making this a competitive market. 

The disadvantages:

• Solar panels are expensive to buy and install. With most solar panel installations lasting between 20 and 25 years and more, with the right maintenance, the initial cost can usually be paid back within the first 8 to 12 years. However, homeowners will need an initial investment of around £6,000 to £8,000 for a 4kW system which is the go-to system size. 
• Solar panels don’t work very well in cloudy conditions though they will still receive some sunlight. 
• Solar panels don’t generate power at night. This is where solar battery storage comes into play. Solar batteries can store energy that is generated but not used during the day for use during the night or on gloomy days when the sun isn’t shining much. 
• As solar panels can't store energy, you have to use the electricity they generate when the sun is shining. Solar batteries can be used to store excess energy, but they are expensive. 
• Solar panels are not very efficient yet.  Solar panel efficiency rates are expected to improve slowly over time, as developers make small gains each year or two. Multi-layered panels like the perovskite-silicon tandem panel have the potential to increase solar efficiency, but development is ongoing. 

Solar Energy Facts for Kids

Here are some fun and interesting facts about solar power that you probably didn’t know before!

• The Earth receives more energy from the sun in one hour than the planet uses in one year!
• Solar energy is almost 200 years old! In 1839, Alexandre Edmond Becquerel discovered the ‘photovoltaic effect’ which explains how electricity is generated from direct sunlight, otherwise known as solar energy.
• For solar panels to supply the world’s electrical needs, less than 1% of the land would need to be covered in solar panels.
• Wind is actually a form of solar power. It is created by the uneven heating of the Earth’s surface.
• Solar panels can work for decades. In fact, some of the panels that were installed in the 1970s are still working and generating electricity today.
• The solar cell was invented by Russell Ohl in 1941. National Aeronautics and Space Administration (NASA) was the first to adopt solar technology in the 1950s, using it aboard the satellite Vanguard. 
• Solar energy can be stored in salt. Known as molten-salt technology or molten-salt energy storage (MSES), this process uses concentrated sunlight to melt salt at 220 degrees Celsius. The salt is kept in its liquid form in an insulated storage tank. The thermal energy can be usefully stored for up to a week if it is properly insulated. When electricity is required, the hot molten salt is pumped to a conventional steam generator to produce superheated steam for powering a conventional turbine/generator set, the same as those used in any coal, oil, or nuclear power plant. Many solar thermal power plants now use this technology. 
• Some of the world’s largest solar power plants are located in China, India, and the Middle East, with capacities reaching several gigawatts (GW). These vast installations cover many square kilometres and generate electricity for hundreds of thousands of homes.
• Over their lifetime, solar panels generate far more electricity than is used in their manufacture, and they do so without producing radioactive waste.
• The amount of energy that is used to create solar panels is actually paid back through clean electricity production within one or two years, making it much cleaner than people think.

How much do Solar Panels Cost?

Now that you know how solar panels work, you may be ready to ask the big question.. How much do solar panels cost?

How do solar panels work with your electricity bill? Three things can happen with the electricity your panels generate during daylight hours. 

• It is used at the point of generation within your home or business. Most homes have an idle electrical demand, for things like your fridge, phones, alarms, heating controls etc
• It is sent to your battery for use on demand when your electrical usage is higher than the output of the solar panels. Especially, at night. 
• It is sent back to the grid (basically to your neighbours). In this case you may be applicable for the Smart Export Guarantee (SEG). Check with your energy provider for their terms and conditions.   
   

Please check this guide for all the information you need. The infographic below will give you a vague idea, if that's all you're looking for. 

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