How a solar PV system works

Solar PV systems are a great way to generate energy from the sun and reduce your carbon footprint.

To understand what they mean and how they work, let’s start with the basics —  “PV” is the abbreviation for “photovoltaics”. A solar PV system is a  power system  that convert sunlight into electricity by using the photovoltaic effect.  

What are the basic principles of a solar PV system, and how does it work?

Solar PV panels use cells to convert sunlight into electricity. When the sun shines on the cell it creates an electric field across the layers causing electricity to flow. The stronger the light, the greater the flow of electricity.

Each panel generates a relatively small amount of energy but when linked together with other panels, they produce higher amounts of energy.

What are the components ?

A solar PV system consists of two or more solar panels combined with an inverter and other electrical and mechanical accessories.

• Photovoltaic modules
• Support structures of modules
• Inverter
• Electric cables

Side note, solar PV systems greatly vary in size from rooftop systems and portable systems to  massive utility-scale generation plants.

A solar PV system can operate in different ways.

• They can operate by themselves as off-grid systems.  An off-grid residential solar system is completely disconnected from the traditional electric power grid.
• They can be connected to the utility grid.
• They can be grid-tied. On-grid – or in other words “grid-tied” – solar systems are considered to be the most common type of residential solar systems worldwide.

If you want to learn more about the types of solar PV systems, have a look at our article Types of Residential Solar Energy Systems.

Direct Current (DC) and Alternate Current (AC)

To understand how solar PV systems work, first we need to know what direct current and alternate current electricity are, and how they are generated by the system.

Solar panels generate direct current (DC) electricity which flows consistently in one direction. On the other hand, households and other buildings use current (AC) electricity for increased efficiency and decreased losses during transmission, where  the flow of electric charge periodically reverses.  That’s why an inverter is needed to convert the energy output from solar panels into a usable AC electricity form, so that you can use it  in your home or workplace.

Any building that is connected to the electrical grid will have a utility meter that your energy provider uses to measure and supply power to your home. When you install solar panels on your roof, they are eventually connected to your home’s utility meter. The production of your solar system can be accessed and measured by this meter.

When your solar power system is producing more electricity than you consume, it feeds the excess power back into the grid.

If you want to know more about solar batteries, we got you covered. To take a deep dive into what happens to the surplus energy, read our article Everything you need to know about solar batteries.

How a solar system works in 6 steps

As we mentioned before, the PV cells on the solar panels absorb the sun’s light and convert solar energy into electricity.  A module is created by stringing together these cells, which are made of a semiconductor that transmits energy, such as silicon.

1. The semiconductor in the solar panels absorbs sunlight.
2. Sunlight sets electrons free from their place in the semiconductor.
3. Dislodged electrons, each carrying a negative charge, flow across the cell toward the front surface.
4. This creates an imbalance in charge between the front and the back of the cell.
5. This imbalance creates a voltage potential like the negative and positive terminals of a battery
6. The current is collected on wires — it can be used immediately or stored in a solar battery.

Side note,  despite the common belief that “solar systems do not operate solar cells can still generate electricity even on cloudy days, but not as much as on sunny days, as we also mentioned in our article “10 Solar Myths and Facts You Need to Know“.

There are lots of advantages that come with a solar PV system. One of them is, you do not need to switch the system on in the morning or switch it off at night. The system will do it automatically.

You also do not need to switch between solar power and the grid, as your solar system can determine when to do so based on the amount of energy being consumed in your home.  In fact, a solar system requires very little maintenance which means you will hardly notice it is there.

The first thing you need to know about a solar PV system is, photovoltaic cells in the panel absorb sun’s light and convert solar energy to DC electricity.  The second important point is that an inverter converts DC electricity to AC electricity, for increased efficiency and decreased losses during the transmission. Congrats – now you are done with the basics of the solar PV systems!

A solar PV system offers many advantages from the possibility to store surplus in the energy in the battery and selling it back to the grid to the automated process of switching on and off.  You can learn more in our article “Types of Residential Solar Systems“.

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