The sun is the largest nuclear power station in the universe, sending 430 quintillion Joules of energy towards the earth every hour!
Put simply, that is enough solar power to electrify the whole of the earth for a whole year, and the sun gives it free-of-charge in only one hour. To harness this ubiquitous energy and put it to good electrical use, all that is required are solar panels.
Millions of Americans today are adopting solar energy with PPM Solar and using solar panels for homes. But how do solar panels work to convert sun rays into electricity that powers our electricals?
What Are Solar Panels Made Of
To understand how solar works, first, we need to know what the panels are made of.
- Solar cells, made of silicon, are the most important feature of solar panels as they are responsible for capturing light energy from the sun and turning it into electricity. Everything else that makes up the panels is meant to shield these cells from damage and enhance how they convert light energy to electrical energy.
- Encapsulation films above, below, and between photovoltaic (PV) cells hold the cells together and act as an adhesive between the solar cells and the top and bottom surfaces of the panel. The most common material employed to fabricate this encapsulation foil is ethyl vinyl acetate (EVA).
- The top surface of solar panels is tempered glass which should be transparent enough to admit light waves which the solar cells can utilize to make electricity, and durable enough to prevent the cells from being damaged by wind, weather elements, dirt, and other forces. Also, the surface is usually roughened to reduce the reflection of light. The goal is to absorb as much light as possible, not to reflect it.
- At the bottom is a back sheet that provides mechanical support and water, electrical, and heat insulation.
- The weather-proof junction box provides cables to connect multiple panels and only allows current to move in one direction from the solar cells to prevent back current that can damage the solar cells.
- Finally, an aluminum frame holds all the above elements together into a strong structure capable of withstanding strong winds and forces. The frame also provides a platform through which the panels can be mounted to the roof, pole, or ground during solar installation, and should be water-tight to prevent the passage of water into the panel’s internals.
How Do Solar PV Cells Work?
Solar cells play the most vital role in generating solar energy for homes. Cells are made of two layers of silicon, n-type at the top and p-type at the bottom.
Light rays from the sun, made on tiny particles called photons, hit against the n-type layer and are absorbed, and travel through to the p-type layer where they lose energy to electrons in the p-type layer.
This gives the electrons energy to move up into the n-type layer and escape into the circuit. This flow of electrons through a circuit produces electricity which lights the lamps and powers your appliances.
What is a Solar Inverter and Why Do You Need One?
Electricity is produced and used in two forms, direct current (DC) and alternating current (AC), with the words “direct” and “alternating” describing the direction of circulation of electricity through circuits.
While some devices can utilize DC power, grid electricity is supplied as AC and since it is much faster to transmit over long distances, and reduces energy losses in transmission thus all houses connected to the grid are configured for AC power.
Solar panels transform light energy into DC electricity. It is, therefore, necessary to transform this DC electricity to AC before distribution around the house and that is where inverters come into play.
Solar inverters change DC power to AC. Furthermore, they also work as communication devices, sending operation information to installers and homeowners for remote monitoring.
Modern inverters are also equipped with a display through which information about the operation of the system can be monitored, and can also be connected to smartphones through apps and networks for remote monitoring.
How Do Solar Panels Generate Electricity? Step-by-Step Explanation
- Light from the sun is made up of energetic tiny particles called photons. When photons hit the cells in a solar panel, they release their energy to electrons in the cells, exciting the electrons.
- The excited electrons migrate from the negatively charged bottom layer of the cell into the positively charged upper layer and through to the circuit. This one-directional circulation of electrons creates DC electricity.
- DC from home solar panels travels through conductive copper wires to the inverter where it is changed into AC that powers the building.
- The AC power is sent through a breaker box for distribution to the building’s circuitry and used to power appliances in the home.
- In a net metering setup, any electricity not taken up by appliances is sent to the grid through your utility meter which turns backward to credit your house for the extra production. The more production goes into the grid, the more you enjoy financially saving with solar panels.