How do solar panels work?
It’s normal to see solar panels on the roofs of houses these days. You may even be looking into having them installed on your own property, in which case it’s normal to wonder how solar panels work. We’ll explain in this guide.
What is a solar panel?
A solar panel is a device that converts sunlight into electricity, which can then be used to power your home.
There are two main types of solar panel in the UK: monocrystalline and polycrystalline. Monocrystalline panels are more efficient but also have a higher cost, while polycrystalline panels cost less, as they’re easier to produce, and have a slightly lower efficiency. The type of solar panel you choose will depend on your budget and how much energy your household uses. The table below shows the key differences between them.
| Comparison | Monocrystalline | Polycrystalline |
|---|---|---|
| Efficiency | 15-24% | 13-20% |
| Cost (per watt) | £1-£1.50 | £0.90-£1 |
| Appearance | Black finish, more sleek design, fewer required for equivalent output | Blue hue, more panels required for equivalent output |
| Lifespan (est.) | 30 years+ | 20 years |
How do solar panels work?
Solar panels consist of photovoltaic (PV) cells, which convert energy from sunlight into electricity. The cells are placed between layers of materials which have semiconducting properties, meaning they conduct electricity in some circumstances but not others. A commonly used material is silicon, which is popular because it’s readily available, durable, resistant to corrosion, non-toxic, and cost-effective. Silicon in solar panels has other atoms added to it, in order to improve its ability to capture and convert solar energy into electricity (this is known as doping).
A single PV cell produces up to two watts of power, so the cells are connected together to form solar panels. Multiple solar panels connected together are known as arrays, and these are connected to the electrical grid. Arrays can be as large or small as you need, making them ideal for properties of any size. Together with mounting structures and solar inverters, arrays make up what’s known as a PV system.
When the sun shines on a solar panel, the PV cells absorb energy from the light, which creates electrical charges. (PV cells don’t need direct sunlight in order to work, but will generate more electricity if there’s more sunshine.) The charges move in response to the internal electrical field in the cells, creating a current and sending electricity into a solar inverter. This inverter converts the electricity to an alternating current and is connected to your fuse board, which means the electricity can then be used in your home. Excess electricity is fed to the National Grid, or stored in a battery system if you have one.
You can use what’s known as a generation meter to see how much electricity your PV system generates.
Depending on location, number of panels, property size, and average energy consumption, solar panels can produce enough electricity to power a home, reducing reliance on the national grid and saving money on energy bills long-term.
For example, a 3.9kWp system without a battery installed in Southampton could offer a saving between £23,000 and £31,000 over a 30-year period.
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Solar panel inverters
The current produced by solar panels is a direct current (DC). However, the current required for household appliances and devices is an alternating current (AC), as most cannot handle the electrical surge of a DC. Because of this, a solar inverter is installed.
The standard DC-to-AC solar converter process involves the following steps:
- The inverter receives the DC.
- It channels the DC through its internal transformer.
- The transformer lowers the voltage, converting the DC to AC.
- The DC runs through two or more transistors.
- The transistors get turned on and off at a rapid pace to feed the two sides of the transformer.
You’ll have enough electricity to power your home once this process is complete.
Read our blog post about solar inverters for more information.
Solar panel batteries
Some PV systems send excess electricity to the National Grid. However, there’s also the option to store this energy in a solar panel battery system and save it for a time when your panels aren’t converting as much sunlight. The battery system will divert excess energy to the battery, then use it to power your home when demand for electricity exceeds supply.
Solar panel battery systems are ideal for households which generate more electricity than they need, as it can save you from relying on the National Grid during times when the solar panels aren’t as effective.
How much power can solar panels produce?
The amount of power produced by solar panels depends on a number of factors:
- The size of the property
- The average energy consumption of the household
- The number of solar panels installed
- The average amount of sunlight in the property’s location
Often, solar panels can produce enough power to meet a household’s needs. Some properties may require electricity from other sources, such as the National Grid or through renewable processes like wind and hydropower.
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It’s evident that solar panels are efficient and cost-effective, with more and more people choosing to have them installed. Hopefully, having an understanding of how they work gives you an insight into why investing in them can be beneficial for your long-term budget and the planet. Please get in touch with us if you have any questions.