5 Facts You Need To Know About Solar Panels
Have you ever wondered how solar panels generate electricity from sun rays? While the technology behind solar energy might seem complex, when broken down, how solar panels work is easy to understand.
Solar panels convert the sun's rays into electricity by exciting electrons in silicon cells using the energy from the sun. This energy can then be used to run your appliances in your home.
To understand this process further, let’s look at it in five simple steps.
1. Photons Hit The Solar Cell
Solar cells consist of a positive and a negative film of silicon placed under a thin slice of glass, also called a PN (Positive/ Negative) junction. A solar cell is essentially a PN junction with a large surface area.
Sunlight travels in packets of energy called photons. As the photons of the sunlight beat down upon the solar cell, they knock the electrons off the silicon. This creates a free electron and a hole. The free electron and hole has sufficient energy to jump out of the depletion zone. If a wire is connected from the cathode (N-type silicon) to the anode (P-type silicon) electrons will flow through the wire. (See infographic)
2. Cells Produce Electricity
This creates an electric voltage that can be collected and channeled. The electricity produced at this stage is DC (direct current) and must be converted to AC (alternating current) suitable for use in your home. (See infographic)
3. Electricity Is Transformed From DC To AC
For regular consumer use an alternating current (AC) is needed – home appliances require AC electricity. This is where the inverter comes in. The DC electricity produced by the PV cells does not have a waveform, but is rather a direct line (hence its name, direct current.)
Basically, to become AC, it must become a sine wave. The inverter references the grid voltage and manipulates the DC voltage to imitate the grid's AC sine wave. Once the solar inverter has transformed DC to the correct amounts of current, voltage and frequency that your AC appliances need to operate, this AC electricity can then be fed into your home safely.
4. Generating Enough Electricity For Your Appliances
An individual solar cell working on its own only produces a very small amount of electricity, about 4 Watts (depending on the materials used). To make your solar panels produce enough electricity to run your appliances, lots of these cells are connected together.
For one solar panel, a typical configuration would be 60 cells which would make a solar panel that produces 60 x 4W = 240W of power. However these days they are finding better materials to make the cells which can create much more power.
5. Feeding Electricity Back Into The Grid
When your solar power system is producing more electricity than required, it will either be fed into the grid (electrical power lines) or into home battery storage.
The excess power that is fed back into the grid is measured by your electrical meter in your switchboard that must be setup to read net export. It will be regulated on your power bill as a feed-in tariff. If you would like to find out more about the best feed-in tariffs currently on the market, fill out the contact form and one of our friendly solar experts will get in touch with you.