How Solar Panels Work | Energy From Daylight

Solar panels can provide energy for your whole house using only the energy of the sun. The journey that this energy take from the sun to your socket is quite the epic! You might be surprised by some of the steps along the way. Read on to learn more – the complete guide to how solar panels work.

Solar Energy From the Sun (Light)

Solar power starts 149,000,000 kilometers away at our nearest star, the sun. There, hydrogen fuses into Helium at a temperature of thousands of degrees. This reaction gives off an enormous amount of energy in the form of sunlight. Next, the sunlight begins its journey to the Earth, a trip that takes around 8 minutes.

Image of the sun.  Ultimately, all solar panels work based on energy that comes from the sun.
The Sun is the Ultimate Source of All Solar Energy

Solar Cells turn Light Into Electricity

Some particles of light from the sun reach the surface of a solar panel. Then they pass through the panel’s glass cover and reach the solar cells inside. These cells are called “photovoltaic” because they turn photons of light into Volts of electricity. Usually, one solar cell gives around 0.5 Volts and 10 amps in full sunshine. Brighter light gives you more amps, but doesn’t make much difference to the voltage. Interestingly though, you can increase the voltage of a solar cell by decreasing the temperature. That’s why solar panels work so well on cold days.

How solar cells work. Image License: CC-BY. Credit: energyd.ie

Many Cells Make a Solar Panel

A typical solar panel has 60 solar cells inside. These cells are soldered into a long chain to increase the voltage. The result is that a typical solar panel will be rated for around 30 volts and 10 amps. While solar cells are powerful, they are also delicate. That’s why solar panels have a tempered glass cover and a watertight back-sheet to protect the cells. Some back-sheets are transparent, letting extra light in from the back of the panel for added power output.

Solar panels by combining the output of many smaller solar cells. Image License: CC-BY. Credit: energyd.ie

Solar Panels Work in “Strings”

A single solar panel can provide 10 amps and 30 Volts, which is a decent amount of power. However, to power your home, you will need more. That’s why you’ll generally see at least 4 solar panels working together in a string. In the example below, 6 solar panels are connected in a string to give a total of 180 Volts.

How solar panels work as part of a string. Image License: CC-BY. Credit: energyd.ie
6 solar panels on the roof on house in Ireland.  Shows how a string of solar panels look on the roof of a house.
A string of 6 solar panels on the roof of a house in Ireland. Image License: CC-BY. Credit: energyd.ie

Solar Panels Need an Inverter to Work Correctly

A string of solar panels on your roof will work to provide you with a supply of clean, renewable electricity. However, there’s another key step before this electricity is ready to use. You see, solar panels produce a type of electricity called DC. On the other hand, your house runs on another type of electricity called AC. You need some way to change the DC from the panels to AC for your house. That’s where the inverter comes in.

The inverter is a device that converts DC from your solar panels into AC that you can use in your sockets. In practical terms, it’s a box that’s about the size of an old computer tower. This means that it’s easy to find an out-of-the way location to install your inverter. On the wall of a garage or in the attic are popular places to install inverters, for example.

Solar Power to Your Home

The last stage of how solar panels work is for the AC electricity to flow from the inverter to your electrical appliances. First of all, the electricity travels down a wire from your inverter to your fuse box. Once in your fuse box, the solar electricity can take a direct path to all the appliances in your house.

How solar panels work as part of a solar panel system.  DC from a string of solar panels is fed into a DC-AC inverter.  The AC output current from the inverter flows into the fuse box.  Finally, electricity from the fuse box flows into appliances in the home.
How solar panels provide electricity – from panels on your roof to appliances in your house. Image License: CC-BY. Credit: energyd.ie

Storing Surplus Solar Power for Later

In the middle of the day when your solar panels are working at their best, you’ll often have surplus electricity available. It makes to store this surplus electricity so that you can use it later. There are two main ways to do this. The first way is to store the electricity in a battery. The second way is to use the surplus electricity to heat a cylinder of water that you can use later. Follow this link to learn more about storing surplus solar electricity for later.

How Solar Panels Save You Money

In Ireland, solar panels can provide you with upwards of 50% of your electricity needs for the year. This means that you could cut your electricity bill by half or even more my installing solar panels on your roof. Better still, the government will give you a grant of up to €2,400 to install solar panels now. You can also earn money by exporting your surplus solar electricity to the grid.